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Mwaanga G, Ford J, Yukich J, Chanda B, Ashton RA, Chanda J, Munsanje B, Muntanga E, Mulota M, Simuyandi C, Mulala B, Simubali L, Saili K, Simulundu E, Miller J, Hamainza B, Orange E, Wagman J, Mburu MM, Harris AF, Entwistle J, Littrell M. Residual bioefficacy of attractive targeted sugar bait stations targeting malaria vectors during seasonal deployment in Western Province of Zambia. Malar J 2024; 23:169. [PMID: 38811947 PMCID: PMC11138038 DOI: 10.1186/s12936-024-04990-3] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/20/2023] [Accepted: 05/18/2024] [Indexed: 05/31/2024] Open
Abstract
BACKGROUND The primary vector control interventions in Zambia are long-lasting insecticidal nets and indoor residual spraying. Challenges with these interventions include insecticide resistance and the outdoor biting and resting behaviours of many Anopheles mosquitoes. Therefore, new vector control tools targeting additional mosquito behaviours are needed to interrupt transmission. Attractive targeted sugar bait (ATSB) stations, which exploit the sugar feeding behaviours of mosquitoes, may help in this role. This study evaluated the residual laboratory bioefficacy of Westham prototype ATSB® Sarabi v.1.2.1 Bait Station (Westham Ltd., Hod-Hasharon, Israel) in killing malaria vectors in Western Province, Zambia, during the first year of a large cluster randomized phase-III trial (Clinical Trials.gov Identifier: NCT04800055). METHODS This was a repeat cross-sectional study conducted within three districts, Nkeyema, Kaoma, and Luampa, in Western Province, Zambia. The study was conducted in 12 intervention clusters among the 70 trial clusters (35 interventions, 35 controls) between December 2021 and June 2022. Twelve undamaged bait stations installed on the outer walls of households were collected monthly (one per cluster per month) for bioassays utilizing adult female and male Anopheles gambiae sensu stricto (Kisumu strain) mosquitoes from a laboratory colony. RESULTS A total of 84 field-deployed ATSB stations were collected, and 71 ultimately met the study inclusion criteria for remaining in good condition. Field-deployed stations that remained in good condition (intact, non-depleted of bait, and free of dirt as well as mold) retained high levels of bioefficacy (mean induced mortality of 95.3% in males, 71.3% in females, 83.9% combined total) over seven months in the field but did induce lower mortality rates than non-deployed ATSB stations (mean induced mortality of 96.4% in males, 87.0% in females, 91.4% combined total). There was relatively little variation in corrected mortality rates between monthly rounds for those ATSB stations that had been deployed to the field. CONCLUSION While field-deployed ATSB stations induced lower mortality rates than non-deployed ATSB stations, these stations nonetheless retained relatively high and stable levels of bioefficacy across the 7-month malaria transmission season. While overall mean mosquito mortality rates exceeded 80%, mean mortality rates for females were 24 percentage points lower than among males and these differences merit attention and further evaluation in future studies. The duration of deployment was not associated with lower bioefficacy. Westham prototype ATSB stations can still retain bioefficacy even after deployment in the field for 7 months, provided they do not meet predetermined criteria for replacement.
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Affiliation(s)
| | - Jacob Ford
- Center for Applied Malaria Research and Evaluation, Department of Tropical Medicine, Tulane University School of Public Health and Tropical Medicine, New Orleans, USA
| | - Joshua Yukich
- Center for Applied Malaria Research and Evaluation, Department of Tropical Medicine, Tulane University School of Public Health and Tropical Medicine, New Orleans, USA
| | | | - Ruth A Ashton
- Center for Applied Malaria Research and Evaluation, Department of Tropical Medicine, Tulane University School of Public Health and Tropical Medicine, New Orleans, USA
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2
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Kuetche MTC, Tabue RN, Fokoua-Maxime CD, Evouna AM, Billong S, Kakesa O. Prevalence and risk factors determinants of the non-use of insecticide-treated nets in an endemic area for malaria: analysis of data from Cameroon. Malar J 2023; 22:205. [PMID: 37407962 DOI: 10.1186/s12936-023-04510-9] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/19/2022] [Accepted: 02/21/2023] [Indexed: 07/07/2023] Open
Abstract
BACKGROUND Malaria is the main cause of morbidity and mortality in Cameroon. Insecticide-treated nets (ITNs) significantly reduce malaria transmission, but their use is not common in the population. This study aimed to estimate the nationwide prevalence of the non-use of ITNs and identify its major determinants. METHODS A cross-sectional study was conducted on interview data collected in households selected across all the regions of Cameroon through a non-probabilistic, random, 2-stage stratified sampling process. Descriptive statistics were used to describe the distribution of baseline characteristics across the households, and statistical tests assessed if the distribution of these characteristics differed significantly based on the non-use of ITNs, with 0.05 serving as a threshold of the p-value for statistical significance. The prevalence of the non-use of ITNs was estimated, and logistic regression models were used to tally the odds ratios of the associations between various factors and the non-use of ITNs, along with their 95% confidence intervals. The sensitivity, specificity, and area under the receiver operating characteristic (ROC) curve (AUC) were determined, and the Hosmer Lemeshow test was used to measure the goodness of fit of each statistical model. RESULTS Of the 7593 households interviewed, 77% had at least one ITN and 59% of the population used ITNs. Only 72% of the population with at least one ITN used it. The logistic model of the multivariate analysis was significant at a 5% threshold. The AUC was 0.7087 and the error rate was 18.01%. The sensitivity and specificity of the model were 97.56% and 13.70%, respectively. The factors that were associated with ITN use were the presence of sufficient nets in the household (p < 0.0001), the region of residence (p < 0.0001), the level of education of the respondent (p < 0.0001), and the standard of living (p = 0.0286). Sex, age, colour preferences, as well as the shape and size of the nets were not associated with ITN use. CONCLUSIONS The use of ITNs in Cameroon was low and varied according to specific factors. These identified factors could be used as the foundations of effective sensitization campaigns on the importance of ITNs.
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Affiliation(s)
| | | | - C D Fokoua-Maxime
- School of Public Health, New York State University at Albany, Albany, NY, USA
| | - Armel M Evouna
- Cameroon Field Epidemiology Training Program, Yaoundé, Cameroon
| | - Serge Billong
- National Committee Against HIV-AIDS, Yaoundé, Cameroon
| | - Olivier Kakesa
- President's Malaria Initiative (PMI)-Measure Malaria Project, Yaoundé, Cameroon
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3
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Unwin HJT, Sherrard-Smith E, Churcher TS, Ghani AC. Quantifying the direct and indirect protection provided by insecticide treated bed nets against malaria. Nat Commun 2023; 14:676. [PMID: 36750566 PMCID: PMC9905482 DOI: 10.1038/s41467-023-36356-9] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/19/2022] [Accepted: 01/27/2023] [Indexed: 02/09/2023] Open
Abstract
Long lasting insecticidal nets (LLINs) provide both direct and indirect protection against malaria. As pyrethroid resistance evolves in mosquito vectors, it will be useful to understand how the specific benefits LLINs afford individuals and communities may be affected. Here we use modelling to show that there is no minimum LLIN usage needed for users and non-users to benefit from community protection. Modelling results also indicate that pyrethroid resistance in local mosquitoes will likely diminish the direct and indirect benefits from insecticides, leaving the barrier effects intact, but LLINs are still expected to provide enhanced benefit over untreated nets even at high levels of pyrethroid resistance.
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Affiliation(s)
- H Juliette T Unwin
- MRC Centre for Global Infectious Disease Analysis, Department of Infectious Disease Epidemiology, Faculty of Medicine, Imperial College London, London, UK.
| | - Ellie Sherrard-Smith
- MRC Centre for Global Infectious Disease Analysis, Department of Infectious Disease Epidemiology, Faculty of Medicine, Imperial College London, London, UK
| | - Thomas S Churcher
- MRC Centre for Global Infectious Disease Analysis, Department of Infectious Disease Epidemiology, Faculty of Medicine, Imperial College London, London, UK
| | - Azra C Ghani
- MRC Centre for Global Infectious Disease Analysis, Department of Infectious Disease Epidemiology, Faculty of Medicine, Imperial College London, London, UK
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4
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Ngonghala CN. Assessing the impact of insecticide-treated nets in the face of insecticide resistance on malaria control. J Theor Biol 2022; 555:111281. [PMID: 36154815 DOI: 10.1016/j.jtbi.2022.111281] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/23/2022] [Revised: 09/01/2022] [Accepted: 09/17/2022] [Indexed: 01/14/2023]
Abstract
The mosquito-borne disease, malaria, continues to impose a devastating health and economic burden worldwide. In malaria-endemic areas, insecticide-treated nets (ITNs) have been useful in curtailing the burden of the disease. However, mosquito resistance to insecticides, decay in ITN efficacy, net attrition, etc., undermine the effectiveness of ITNs in combatting malaria. In this study, mathematical models that account for asymptomatic infectious humans (through a partially immune class or a separate asymptomatic infectious class), insecticide resistance, and decay in ITN efficacy are proposed and analyzed. Analytical and numerical results of the models when ITN efficacy is constant show that there are parameter regimes for which a backward bifurcation occurs. Local and global sensitivity analyses are performed to identify parameters (some of which are potential targets for disease control) with the most significant influence on the control reproduction (Rc) and disease prevalence. These influential parameters include the maximum biting rate of resistant mosquitoes, ITN coverage, initial ITN efficacy against sensitive mosquitoes, the probability that an infectious mosquito (human) infects a susceptible human (mosquito), and the rate at which adult mosquitoes develop (lose) resistance to insecticides. Simulations of the models show that accounting for asymptomatic infectious humans through a separate class, or not accounting for the decay in ITN efficacy leads to an underestimation of disease burden. In particular, if the initial efficacy of ITNs against sensitive and resistance mosquitoes is 96%, the minimum ITN coverage required to reduce Rc below one (and hence, contain malaria) is approximately 11% (27%) lower when ITN efficacy is averaged (constant) for a model with a separate asymptomatic class. For the model with a partially immune class and decaying ITN efficacy, reducing Rc below one is impossible even if the entire populace uses ITNs. The study shows that replacing ITNs before their prescribed lifespans, or designing ITNs with longer lifespans is important for malaria control. Furthermore, the study shows that piperonyl butoxide (PBO) ITNs (which inhibit or reverse insecticide resistance) outperform regular ITNs in malaria control. Hence, prospects for effectively controlling malaria are enhanced by widespread use of high quality ITNs (e.g. PBO ITNs), especially if the useful lifespans of the ITNs are long enough and the ITNs are replaced before the end of their useful lifespans.
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Affiliation(s)
- Calistus N Ngonghala
- Department of Mathematics, University of Florida, 1400 Stadium Rd, Gainesville, FL 32611, United States of America; Emerging Pathogens Institute, University of Florida, 2055 Mowry Rd, Gainesville, FL 32610, United States of America; Center for African Studies, University of Florida, 427 Grinter Hall 1523 Union Rd, Gainesville, FL 32611, United States of America.
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5
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Inferring the epidemiological benefit of indoor vector control interventions against malaria from mosquito data. Nat Commun 2022; 13:3862. [PMID: 35790746 PMCID: PMC9256631 DOI: 10.1038/s41467-022-30700-1] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/03/2022] [Accepted: 05/11/2022] [Indexed: 12/03/2022] Open
Abstract
The cause of malaria transmission has been known for over a century but it is still unclear whether entomological measures are sufficiently reliable to inform policy decisions in human health. Decision-making on the effectiveness of new insecticide-treated nets (ITNs) and the indoor residual spraying of insecticide (IRS) have been based on epidemiological data, typically collected in cluster-randomised control trials. The number of these trials that can be conducted is limited. Here we use a systematic review to highlight that efficacy estimates of the same intervention may vary substantially between trials. Analyses indicate that mosquito data collected in experimental hut trials can be used to parameterize mechanistic models for Plasmodium falciparum malaria and reliably predict the epidemiological efficacy of quick-acting, neuro-acting ITNs and IRS. Results suggest that for certain types of ITNs and IRS using this framework instead of clinical endpoints could support policy and expedite the widespread use of novel technologies. Estimating the effectiveness of malaria vector control interventions has typically relied on resource-intensive cluster randomised trials. Here, the authors estimate changes in malaria prevalence using entomological data from experimental hut trials, which may provide an alternative route to approval of interventions in some situations.
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6
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Nguyen TT, Nguyen XX, Wilson-Barthes M, Sawada I, Muela J, Hausmann-Muela S, Pham TV, Van Nguyen H, Van Nguyen V, Tran DT, Gryseels C, D'Alessandro U, Grietens KP, Erhart A. Why using bed nets is a challenge among minority populations in Central Vietnam. Malar J 2022; 21:87. [PMID: 35292018 PMCID: PMC8922825 DOI: 10.1186/s12936-022-04114-9] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/10/2021] [Accepted: 03/02/2022] [Indexed: 11/10/2022] Open
Abstract
BACKGROUND Despite freely distributed insecticide-treated nets (ITNs) and health information campaigns to increase their use among populations at risk, malaria transmission persists in forested areas in Vietnam, especially among ethnic minority communities. A mixed-methods study was conducted in four villages of Ca Dong and M'nong ethnicity in Central Vietnam between 2009 and 2011 to assess factors limiting the uptake of ITNs. METHODS The mixed-methods research design consisted of a qualitative study to explore the context and barriers to ITN use, and a cross-sectional household survey (n = 141) to quantify factors for limited and appropriate net use. RESULTS The Ca Dong and M'nong's livelihood was dependent on swidden farming in the forest. Poverty-related factors, including the lack of beds, blankets, the practice of sleeping around the kitchen fire and deteriorated ITNs due to open housing structures, were reasons for alternative and non-use of ITNs. When household members stayed overnight in plot huts at fields, ITNs were even more unavailable and easily deteriorated. 72.5% of households reported having received one net for every two persons, and 82.2% of participants reported to have used ITNs the night before the survey. However, only 18.4% of participants were estimated to be effectively protected by ITNs after accounting for the availability of torn ITNs and the way ITNs were used, for example as blankets, at both village and fields. Multi-variable logistic regression showed the effect of four significant factors for appropriate ITN use: i) being female (AOR = 8.08; p = 0.009); ii) aware of mosquito bites as the sole cause of malaria (AOR = 7.43; p = 0.008); iii) not sleeping around the kitchen fire (AOR = 24.57; p = 0.001); and iv) having sufficient number of ITNs in the household (AOR = 21.69; p = 0.001). CONCLUSION This study showed how social factors rooted in poverty and swidden agriculture limited the effective use of ITNs, despite high coverage, among ethnic minority populations in Central Vietnam. An in-depth understanding of the local context is essential to develop specific indicators for measuring ITN use.
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Affiliation(s)
- Thuan Thi Nguyen
- Socio-Ecological Health Research Unit, Department of Public Health, Institute of Tropical Medicine, Antwerp, Belgium. .,National Institute of Malariology, Parasitology and Entomology, Hanoi, Vietnam.
| | - Xa Xuan Nguyen
- National Institute of Malariology, Parasitology and Entomology, Hanoi, Vietnam
| | - Marta Wilson-Barthes
- International Health Institute, Brown University School of Public Health, Providence, USA
| | - Ikumi Sawada
- Department of Clinical Tropical Medicine, Institute of Tropical Medicine, Graduate School of Biomedical Science, Nagasaki University, Nagasaki, Japan
| | - Joan Muela
- University Ramon I Virgili, Tarragona, Spain.,Partners for Applied Social Sciences, PASS International, Tessenderlo, Belgium
| | | | - Thanh Vinh Pham
- National Institute of Malariology, Parasitology and Entomology, Hanoi, Vietnam
| | - Hong Van Nguyen
- National Institute of Malariology, Parasitology and Entomology, Hanoi, Vietnam
| | | | - Duong Thanh Tran
- National Institute of Malariology, Parasitology and Entomology, Hanoi, Vietnam
| | - Charlotte Gryseels
- Socio-Ecological Health Research Unit, Department of Public Health, Institute of Tropical Medicine, Antwerp, Belgium
| | - Umberto D'Alessandro
- Medical Research Council Unit The Gambia at the London School of Hygiene and Tropical Medicine, Fajara, The Gambia
| | - Koen Peeters Grietens
- Socio-Ecological Health Research Unit, Department of Public Health, Institute of Tropical Medicine, Antwerp, Belgium.,Partners for Applied Social Sciences, PASS International, Tessenderlo, Belgium.,School of Tropical Medicine and Global Health, Nagasaki University, Nagasaki, Japan
| | - Annette Erhart
- Medical Research Council Unit The Gambia at the London School of Hygiene and Tropical Medicine, Fajara, The Gambia
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7
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Grant J, Sagara I, Zongo I, Cairns M, Yerbanga RS, Diarra M, Zoungrana C, Issiaka D, Nikièma F, Sompougdou F, Tapily A, Kaya M, Haro A, Sanogo K, Sienou AA, Traore S, Thera I, Yalcouye H, Kuepfer I, Snell P, Milligan P, Ockenhouse C, Ofori-Anyinam O, Tinto H, Djimde A, Chandramohan D, Greenwood B, Dicko A, Ouédraogo JB. Impact of seasonal RTS,S/AS01 E vaccination plus seasonal malaria chemoprevention on the nutritional status of children in Burkina Faso and Mali. Malar J 2022; 21:59. [PMID: 35193608 PMCID: PMC8864823 DOI: 10.1186/s12936-022-04077-x] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/08/2021] [Accepted: 02/06/2022] [Indexed: 11/10/2022] Open
Abstract
BACKGROUND A recent trial in Burkina Faso and Mali showed that combining seasonal RTS,S/AS01E malaria vaccination with seasonal malaria chemoprevention (SMC) substantially reduced the incidence of uncomplicated and severe malaria in young children compared to either intervention alone. Given the possible negative effect of malaria on nutrition, the study investigated whether these children also experienced lower prevalence of acute and chronic malnutrition. METHODS In Burkina Faso and Mali 5920 children were randomized to receive either SMC alone, RTS,S/AS01E alone, or SMC combined with RTS,S/AS01E for three malaria transmission seasons (2017-2019). After each transmission season, anthropometric measurements were collected from all study children at a cross-sectional survey and used to derive nutritional status indicators, including the binary variables wasted and stunted (weight-for-height and height-for-age z-scores below - 2, respectively). Binary and continuous outcomes between treatment groups were compared by Poisson and linear regression. RESULTS In 2017, compared to SMC alone, the combined intervention reduced the prevalence of wasting by approximately 12% [prevalence ratio (PR) = 0.88 (95% CI 0.75, 1.03)], and approximately 21% in 2018 [PR = 0.79 (95% CI 0.62, 1.01)]. Point estimates were similar for comparisons with RTS,S/AS01E, but there was stronger evidence of a difference. There was at least a 30% reduction in the point estimates for the prevalence of severe wasting in the combined group compared to the other two groups in 2017 and 2018. There was no difference in the prevalence of moderate or severe wasting between the groups in 2019. The prevalence of stunting, low-MUAC-for-age or being underweight did not differ between groups for any of the three years. The prevalence of severe stunting was higher in the combined group compared to both other groups in 2018, and compared to RTS,S/AS01E alone in 2017; this observation does not have an obvious explanation and may be a chance finding. Overall, malnutrition was very common in this cohort, but declined over the study as the children became older. CONCLUSIONS Despite a high burden of malnutrition and malaria in the study populations, and a major reduction in the incidence of malaria in children receiving both interventions, this had only a modest impact on nutritional status. Therefore, other interventions are needed to reduce the high burden of malnutrition in these areas. TRIAL REGISTRATION https://www.clinicaltrials.gov/ct2/show/NCT03143218 , registered 8th May 2017.
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Affiliation(s)
- Jane Grant
- London School of Hygiene and Tropical Medicine, Keppel St., London, WC1E 7HT, UK.
| | - Issaka Sagara
- Malaria Research and Training Center, University of Science, Techniques, and Technologies of Bamako, Bamako, Mali
| | - Issaka Zongo
- Institut de Recherche en Sciences de La Santé, Bobo-Dioulasso, Burkina Faso
| | - Matthew Cairns
- London School of Hygiene and Tropical Medicine, Keppel St., London, WC1E 7HT, UK
| | | | - Modibo Diarra
- Malaria Research and Training Center, University of Science, Techniques, and Technologies of Bamako, Bamako, Mali
| | - Charles Zoungrana
- Institut de Recherche en Sciences de La Santé, Bobo-Dioulasso, Burkina Faso
| | - Djibrilla Issiaka
- Malaria Research and Training Center, University of Science, Techniques, and Technologies of Bamako, Bamako, Mali
| | - Frédéric Nikièma
- Institut de Recherche en Sciences de La Santé, Bobo-Dioulasso, Burkina Faso
| | | | - Amadou Tapily
- Malaria Research and Training Center, University of Science, Techniques, and Technologies of Bamako, Bamako, Mali
| | - Mahamadou Kaya
- Malaria Research and Training Center, University of Science, Techniques, and Technologies of Bamako, Bamako, Mali
| | - Alassane Haro
- Institut de Recherche en Sciences de La Santé, Bobo-Dioulasso, Burkina Faso
| | - Koualy Sanogo
- Malaria Research and Training Center, University of Science, Techniques, and Technologies of Bamako, Bamako, Mali
| | - Abdoul Aziz Sienou
- Institut de Recherche en Sciences de La Santé, Bobo-Dioulasso, Burkina Faso
| | - Seydou Traore
- Malaria Research and Training Center, University of Science, Techniques, and Technologies of Bamako, Bamako, Mali
| | - Ismaila Thera
- Malaria Research and Training Center, University of Science, Techniques, and Technologies of Bamako, Bamako, Mali
| | - Hama Yalcouye
- Malaria Research and Training Center, University of Science, Techniques, and Technologies of Bamako, Bamako, Mali
| | - Irene Kuepfer
- London School of Hygiene and Tropical Medicine, Keppel St., London, WC1E 7HT, UK
| | - Paul Snell
- London School of Hygiene and Tropical Medicine, Keppel St., London, WC1E 7HT, UK
| | - Paul Milligan
- London School of Hygiene and Tropical Medicine, Keppel St., London, WC1E 7HT, UK
| | | | | | - Halidou Tinto
- Institut de Recherche en Sciences de La Santé, Bobo-Dioulasso, Burkina Faso
| | - Abdoulaye Djimde
- Malaria Research and Training Center, University of Science, Techniques, and Technologies of Bamako, Bamako, Mali
| | - Daniel Chandramohan
- London School of Hygiene and Tropical Medicine, Keppel St., London, WC1E 7HT, UK
| | - Brian Greenwood
- London School of Hygiene and Tropical Medicine, Keppel St., London, WC1E 7HT, UK
| | - Alassane Dicko
- Malaria Research and Training Center, University of Science, Techniques, and Technologies of Bamako, Bamako, Mali
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Kamau E, Yates A, Maisiba R, Singoei V, Opot B, Adeny R, Arima CO, Otieno V, Sumbi CS, Okoth RO, Abdi F, Mwalo M, Ochola J, Otieno J, Ake J, Imbach M, Turley HA, Juma D, Akala HM, Owuoth J, Andagalu B, Crowell TA, Nwoga C, Cowden J, Polyak CS. Epidemiological and clinical implications of asymptomatic malaria and schistosomiasis co-infections in a rural community in western Kenya. BMC Infect Dis 2021; 21:937. [PMID: 34503469 PMCID: PMC8431856 DOI: 10.1186/s12879-021-06626-2] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/10/2021] [Accepted: 07/30/2021] [Indexed: 11/10/2022] Open
Abstract
BACKGROUND Malaria and schistosomiasis present considerable disease burden in tropical and sub-tropical areas and severity is worsened by co-infections in areas where both diseases are endemic. Although pathogenesis of these infections separately is well studied, there is limited information on the pathogenic disease mechanisms and clinical disease outcomes in co-infections. In this study, we investigated the prevalence of malaria and schistosomiasis co-infections, and the hematologic and blood chemistry abnormalities in asymptomatic adults in a rural fishing community in western Kenya. METHODS This sub-study used samples and data collected at enrollment from a prospective observational cohort study (RV393) conducted in Kisumu County, Kenya. The presence of malaria parasites was determined using microscopy and real-time-PCR, and schistosomiasis infection by urine antigen analysis (CCA). Hematological analysis and blood chemistries were performed using standard methods. Statistical analyses were performed to compare demographic and infection data distribution, and hematologic and blood chemistry parameters based on different groups of infection categories. Clinically relevant hematologic conditions were analyzed using general linear and multivariable Poisson regression models. RESULTS From February 2017 to May 2018, we enrolled 671 participants. The prevalence of asymptomatic Plasmodium falciparum was 28.2% (157/556) and schistosomiasis 41.2% (229/562), with 18.0% (100/556) of participants co-infected. When we analyzed hematological parameters using Wilcoxon rank sum test to evaluate median (IQR) distribution based on malarial parasites and/or schistosomiasis infection status, there were significant differences in platelet counts (p = 0.0002), percent neutrophils, monocytes, eosinophils, and basophils (p < 0.0001 each). Amongst clinically relevant hematological abnormalities, eosinophilia was the most prevalent at 20.6% (116/562), whereas thrombocytopenia was the least prevalent at 4.3% (24/562). In univariate model, Chi-Square test performed for independence between participant distribution in different malaria parasitemia/schistosomiasis infection categories within each clinical hematological condition revealed significant differences for thrombocytopenia and eosinophilia (p = 0.006 and p < 0.0001, respectively), which was confirmed in multivariable models. Analysis of the pairwise mean differences of liver enzyme (ALT) and kidney function (Creatinine Clearance) indicated the presence of significant differences in ALT across the infection groups (parasite + /CCA + vs all other groups p < .003), but no differences in mean Creatinine Clearance across the infection groups. CONCLUSIONS Our study demonstrates the high burden of asymptomatic malaria parasitemia and schistosomiasis infection in this rural population in Western Kenya. Asymptomatic infection with malaria or schistosomiasis was associated with laboratory abnormalities including neutropenia, leukopenia and thrombocytopenia. These abnormalities could be erroneously attributed to other diseases processes during evaluation of diseases processes. Therefore, evaluating for co-infections is key when assessing individuals with laboratory abnormalities. Additionally, asymptomatic infection needs to be considered in control and elimination programs given high prevalence documented here.
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Affiliation(s)
- Edwin Kamau
- U.S. Military HIV Research Program, Walter Reed Army Institute of Research, Silver Spring, MD, USA
| | - Adam Yates
- U.S. Military HIV Research Program, Walter Reed Army Institute of Research, Silver Spring, MD, USA.,Henry M. Jackson Foundation for the Advancement of Military Medicine, 6720A Rockledge Drive, Suite 400, Bethesda, MD, 20817, USA
| | - Risper Maisiba
- United States Army Medical Research Directorate-Africa, Nairobi, Kenya.,Kenya Medical Research Institute, Kisumu, Kenya
| | - Valentine Singoei
- United States Army Medical Research Directorate-Africa, Nairobi, Kenya.,HJF Medical Research International, Kisumu, Kenya
| | - Benjamin Opot
- United States Army Medical Research Directorate-Africa, Nairobi, Kenya.,Kenya Medical Research Institute, Kisumu, Kenya
| | - Rose Adeny
- United States Army Medical Research Directorate-Africa, Nairobi, Kenya.,Kenya Medical Research Institute, Kisumu, Kenya
| | - Cornel O Arima
- United States Army Medical Research Directorate-Africa, Nairobi, Kenya.,Kenya Medical Research Institute, Kisumu, Kenya
| | - Victor Otieno
- United States Army Medical Research Directorate-Africa, Nairobi, Kenya.,Kenya Medical Research Institute, Kisumu, Kenya
| | - Catherine S Sumbi
- United States Army Medical Research Directorate-Africa, Nairobi, Kenya.,Kenya Medical Research Institute, Kisumu, Kenya
| | - Raphael O Okoth
- United States Army Medical Research Directorate-Africa, Nairobi, Kenya.,Kenya Medical Research Institute, Kisumu, Kenya
| | - Farid Abdi
- United States Army Medical Research Directorate-Africa, Nairobi, Kenya.,Kenya Medical Research Institute, Kisumu, Kenya
| | - Maurine Mwalo
- United States Army Medical Research Directorate-Africa, Nairobi, Kenya.,Kenya Medical Research Institute, Kisumu, Kenya
| | - Jew Ochola
- United States Army Medical Research Directorate-Africa, Nairobi, Kenya.,HJF Medical Research International, Kisumu, Kenya
| | - June Otieno
- United States Army Medical Research Directorate-Africa, Nairobi, Kenya.,Kenya Medical Research Institute, Kisumu, Kenya
| | - Julie Ake
- U.S. Military HIV Research Program, Walter Reed Army Institute of Research, Silver Spring, MD, USA
| | - Michelle Imbach
- U.S. Military HIV Research Program, Walter Reed Army Institute of Research, Silver Spring, MD, USA.,Henry M. Jackson Foundation for the Advancement of Military Medicine, 6720A Rockledge Drive, Suite 400, Bethesda, MD, 20817, USA
| | - Hannah A Turley
- U.S. Military HIV Research Program, Walter Reed Army Institute of Research, Silver Spring, MD, USA.,Henry M. Jackson Foundation for the Advancement of Military Medicine, 6720A Rockledge Drive, Suite 400, Bethesda, MD, 20817, USA
| | - Dennis Juma
- United States Army Medical Research Directorate-Africa, Nairobi, Kenya.,Kenya Medical Research Institute, Kisumu, Kenya
| | - Hoseah M Akala
- United States Army Medical Research Directorate-Africa, Nairobi, Kenya.,Kenya Medical Research Institute, Kisumu, Kenya
| | - John Owuoth
- United States Army Medical Research Directorate-Africa, Nairobi, Kenya.,HJF Medical Research International, Kisumu, Kenya
| | - Ben Andagalu
- United States Army Medical Research Directorate-Africa, Nairobi, Kenya.,Kenya Medical Research Institute, Kisumu, Kenya
| | - Trevor A Crowell
- U.S. Military HIV Research Program, Walter Reed Army Institute of Research, Silver Spring, MD, USA.,Henry M. Jackson Foundation for the Advancement of Military Medicine, 6720A Rockledge Drive, Suite 400, Bethesda, MD, 20817, USA
| | - Chiaka Nwoga
- U.S. Military HIV Research Program, Walter Reed Army Institute of Research, Silver Spring, MD, USA.,Henry M. Jackson Foundation for the Advancement of Military Medicine, 6720A Rockledge Drive, Suite 400, Bethesda, MD, 20817, USA
| | - Jessica Cowden
- United States Army Medical Research Directorate-Africa, Nairobi, Kenya
| | - Christina S Polyak
- U.S. Military HIV Research Program, Walter Reed Army Institute of Research, Silver Spring, MD, USA. .,Henry M. Jackson Foundation for the Advancement of Military Medicine, 6720A Rockledge Drive, Suite 400, Bethesda, MD, 20817, USA.
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Prusty D, Gupta N, Upadhyay A, Dar A, Naik B, Kumar N, Prajapati VK. Asymptomatic malaria infection prevailing risks for human health and malaria elimination. INFECTION GENETICS AND EVOLUTION 2021; 93:104987. [PMID: 34216796 DOI: 10.1016/j.meegid.2021.104987] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/11/2020] [Revised: 06/23/2021] [Accepted: 06/27/2021] [Indexed: 01/09/2023]
Abstract
There has been a consistent rise in malaria cases in the last few years. The existing malaria control measures are challenged by insecticide resistance in the mosquito vector, drug résistance in parasite populations, and asymptomatic malaria (ASM) in healthy individuals. The absence of apparent malaria symptoms and the presence of low parasitemia makes ASM a hidden reservoir for malaria transmission and an impediment in malaria elimination efforts. This review focuses on ASM in malaria-endemic countries and the past and present research trends from those geographical locations. The harmful impacts of asymptomatic malaria on human health and its contribution to disease transmission are highlighted. We discuss certain crucial genetic changes in the parasite and host immune response necessary for maintaining low parasitemia leading to long-term parasite survival in the host. Since the chronic health effects and the potential roles for disease transmission of ASM remain mostly unknown to significant populations, we offer proposals for developing general awareness. We also suggest advanced technology-based diagnostic methods, and treatment strategies to eliminate ASM.
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Affiliation(s)
- Dhaneswar Prusty
- Department of Biochemistry, School of Life Sciences, Central University of Rajasthan, Bandarsindri, Kishangarh, Ajmer, 305817, Rajasthan, India.
| | - Nidhi Gupta
- Department of Biochemistry, School of Life Sciences, Central University of Rajasthan, Bandarsindri, Kishangarh, Ajmer, 305817, Rajasthan, India
| | - Arun Upadhyay
- Department of Biochemistry, School of Life Sciences, Central University of Rajasthan, Bandarsindri, Kishangarh, Ajmer, 305817, Rajasthan, India
| | - Ashraf Dar
- Department of Biochemistry, University of Kashmir, Hazaratbal, Srinagar 190006, Jammu and Kashmir, India
| | - Biswajit Naik
- Department of Biochemistry, School of Life Sciences, Central University of Rajasthan, Bandarsindri, Kishangarh, Ajmer, 305817, Rajasthan, India
| | - Navin Kumar
- School of Biotechnology, Gautam Buddha University, Greater Noida, 201308, UP, India
| | - Vijay Kumar Prajapati
- Department of Biochemistry, School of Life Sciences, Central University of Rajasthan, Bandarsindri, Kishangarh, Ajmer, 305817, Rajasthan, India
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10
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Omotayo AI, Ande AT, Oduola AO, Olakiigbe AK, Ghazali AK, Adeneye A, Awolola ST. Community Knowledge, Attitude and Practices on Malaria Vector Control Strategies in Lagos State, South-West Nigeria. JOURNAL OF MEDICAL ENTOMOLOGY 2021; 58:1280-1286. [PMID: 33420501 DOI: 10.1093/jme/tjaa278] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/02/2020] [Indexed: 06/12/2023]
Abstract
Malaria is a leading public health challenge causing mortality and morbidity in sub-Saharan Africa. Prominent malaria vector control methods employed in sub-Saharan Africa include Long Lasting Insecticide Nets (LLINs) and Indoor Residual spraying (IRS). This study investigated knowledge, attitude and practices (KAP) of malaria vector control methods in Lagos, South-West Nigeria. Structured questionnaires were employed for the cross-sectional survey which was carried out between May and August 2018. Multi-stage sampling technique was used to select Lagos Mainland, Kosofe, and Ojo local government areas (LGAs). Five hundred and twenty questionnaires were used for the study. Data were analyzed for descriptive statistics, whereas χ 2 was used to determine influence of respondents' LGA, level of education and type of dwelling on respondents' attitude and practice. Respondents' LGAs have no significant impact on attitude and practice to malaria vector control methods. However, 'level of education' as well as 'type of dwelling structure' impacted significantly on some practices and attitude. Basically, IRS is the major tool employed in malaria vector control, but sometimes it is used in combination with other methods. A good number of residents also use LLINs. 'Choice of method' employed is mainly based on the effectiveness of method. General perception about LLINs and IRS is that they are effective, cheap and safer. Considering the widespread use of IRS and LLINs for malaria vector control in Lagos, implementation of malaria control programs should consider KAP to these two strategies.
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Affiliation(s)
- Ahmed I Omotayo
- Department of Zoology, University of Ilorin, Ilorin, Nigeria
- Department of Public Health and Epidemiology, Nigeria Institute of Medical Research, Yaba, Lagos, Nigeria
| | - Adeolu T Ande
- Department of Zoology, University of Ilorin, Ilorin, Nigeria
| | | | - Abiodun K Olakiigbe
- Department of Public Health and Epidemiology, Nigeria Institute of Medical Research, Yaba, Lagos, Nigeria
| | - Aishat K Ghazali
- Department of Pharmacy, National Orthopaedic Hospital, Igbobi, Lagos, Nigeria
| | - Adeniyi Adeneye
- Department of Public Health and Epidemiology, Nigeria Institute of Medical Research, Yaba, Lagos, Nigeria
| | - Samson T Awolola
- Department of Public Health and Epidemiology, Nigeria Institute of Medical Research, Yaba, Lagos, Nigeria
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11
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Zebaze Temgoua Kemleu SG, Ngando L, Nguekeng E, Fogang B, Mafo Kapen M, Fopa SI, Biabi MF, Essangui E, Assob Nguedia JC, Ayong L. Diagnostic performance of a rapid whole blood-based RT-LAMP method for malaria diagnosis among apparently healthy blood donors and febrile neonates in Cameroon. PLoS One 2021; 16:e0246205. [PMID: 33508016 PMCID: PMC7842973 DOI: 10.1371/journal.pone.0246205] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/15/2020] [Accepted: 01/14/2021] [Indexed: 11/23/2022] Open
Abstract
Light microscopy and rapid diagnostic tests are the two commonly used methods for malaria diagnosis that rely on the direct use of unprocessed blood samples. However, both methods do not have the level of sensitivity required for malaria diagnosis in cases of low density parasitaemia. We report here the diagnostic performance of a whole blood-based reverse transcription loop-mediated isothermal amplification method for Plasmodium falciparum malaria diagnosis in apparently healthy blood donors and febrile neonates in Cameroon. The presence of malaria parasites in whole blood samples was determined by light microscopy, antigen-based rapid diagnostic test (RDT), and by RT-LAMP using a "lyse and amplify" experimental protocol. Of the 256 blood donors tested, 36 (14.1%) were positive for malaria parasites by light microscopy, 38 (14.8%) were positive by RDT whereas 78 (30.5%) were positive by RT-LAMP. Only light microscopy and RT-LAMP detected infection among the febrile neonates (279 neonates, median age: 2 days, range: 1-9 days), with positivity rates of 8.6% and 12.2%, respectively. The overall concordance between the three methods were 75.9% for RT-LAMP and light microscopy, 75.1% for RT-LAMP and RDT, and 83.9% for light microscopy and RDT. Blood parasite densities were significantly lower in the neonates (mean: 97.6, range: 61-192 parasites/μL) compared to the blood donors (mean: 447.8, range: 63-11 000 parasites/μL). Together, the study demonstrates the usefulness of whole blood RT-LAMP for use in rapid pre-screening of blood donors and suspected neonates to avert severe consequences of P. falciparum infections.
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Affiliation(s)
- Sylvie Georgette Zebaze Temgoua Kemleu
- Malaria Research Unit, Centre Pasteur du Cameroun, Yaounde, Cameroon
- Department of Medical Laboratory Sciences, Faculty of Health Sciences, University of Buea, Buea, Cameroon
| | - Laure Ngando
- Bacteriology Unit, Centre Pasteur du Cameroun, Yaounde, Cameroon
| | | | - Balotin Fogang
- Malaria Research Unit, Centre Pasteur du Cameroun, Yaounde, Cameroon
| | - Marie Mafo Kapen
- Malaria Research Unit, Centre Pasteur du Cameroun, Yaounde, Cameroon
| | | | | | - Estelle Essangui
- Malaria Research Unit, Centre Pasteur du Cameroun, Yaounde, Cameroon
| | - Jules Clement Assob Nguedia
- Department of Medical Laboratory Sciences, Faculty of Health Sciences, University of Buea, Buea, Cameroon
- Faculty of Medicine and Pharmaceutical Sciences, University of Douala, Douala, Cameroon
| | - Lawrence Ayong
- Malaria Research Unit, Centre Pasteur du Cameroun, Yaounde, Cameroon
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12
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Wu L, Mwesigwa J, Affara M, Bah M, Correa S, Hall T, Singh SK, Beeson JG, Tetteh KKA, Kleinschmidt I, D’Alessandro U, Drakeley C. Sero-epidemiological evaluation of malaria transmission in The Gambia before and after mass drug administration. BMC Med 2020; 18:331. [PMID: 33183292 PMCID: PMC7664049 DOI: 10.1186/s12916-020-01785-6] [Citation(s) in RCA: 14] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/06/2020] [Accepted: 09/16/2020] [Indexed: 11/22/2022] Open
Abstract
BACKGROUND As The Gambia aims to achieve malaria elimination by 2030, serological assays are a useful surveillance tool to monitor trends in malaria incidence and evaluate community-based interventions. METHODS Within a mass drug administration (MDA) study in The Gambia, where reduced malaria infection and clinical disease were observed after the intervention, a serological sub-study was conducted in four study villages. Spatio-temporal variation in transmission was measured with a panel of recombinant Pf antigens on a multiplexed bead-based assay. Village-level antibody levels were quantified as under-15 sero-prevalence, sero-conversion rates, and age-adjusted antibody acquisition rates. Antibody levels prior to MDA were assessed for association with persistent malaria infection after community chemoprophylaxis. RESULTS Seasonal changes in antibodies to Etramp5.Ag1 were observed in children under 15 years in two transmission settings-the West Coast and Upper River Regions (4.32% and 31.30% Pf prevalence, respectively). At the end of the malaria season, short-lived antibody responses to Etramp5.Ag1, GEXP18, HSP40.Ag1, EBA175 RIII-V, and Rh2.2030 were lower amongst 1-15 year olds in the West Coast compared to the Upper River, reflecting known differences in transmission. Prior to MDA, individuals in the top 50th percentile of antibody levels had two-fold higher odds of clinical malaria during the transmission season, consistent with previous findings from the Malaria Transmission Dynamics Study, where individuals infected before the implementation of MDA had two-fold higher odds of re-infection post-MDA. CONCLUSIONS Serological markers can serve dual functions as indicators of malaria exposure and incidence. By monitoring age-specific sero-prevalence, the magnitude of age-stratified antibody levels, or identifying groups of individuals with above-average antibody responses, these antigens have the potential to complement conventional malaria surveillance tools. Further studies, particularly cluster randomised trials, can help establish standardised serological protocols to reliably measure transmission across endemic settings.
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Affiliation(s)
- Lindsey Wu
- Faculty of Infectious Tropical Diseases, Department of Infection Biology, London School of Hygiene and Tropical Medicine (LSHTM), London, WC1E 7HT UK
| | - Julia Mwesigwa
- Medical Research Council Unit The Gambia at London School of Hygiene and Tropical Medicine, Fajara, The Gambia
| | - Muna Affara
- Bernhard Nocht Institute for Tropical Medicine (BNITM), Arusha, Tanzania
| | - Mamadou Bah
- Medical Research Council Unit The Gambia at London School of Hygiene and Tropical Medicine, Fajara, The Gambia
| | - Simon Correa
- Medical Research Council Unit The Gambia at London School of Hygiene and Tropical Medicine, Fajara, The Gambia
| | - Tom Hall
- St. George’s University of London (SGUL), London, SW17 0RE UK
| | - Susheel K. Singh
- Department for Congenital Disorders, Statens Serum Institut, Copenhagen, Denmark
- Centre for Medical Parasitology at Department of Immunology and Microbiology, University of Copenhagen, Copenhagen, Denmark
| | - James G. Beeson
- Burnet Institute, Melbourne, Victoria 3004 Australia
- Central Clinical School, Monash University, Melbourne, Victoria Australia
- Department of Medicine, University of Melbourne, Melbourne, Victoria Australia
| | - Kevin K. A. Tetteh
- Faculty of Infectious Tropical Diseases, Department of Infection Biology, London School of Hygiene and Tropical Medicine (LSHTM), London, WC1E 7HT UK
| | - Immo Kleinschmidt
- Faculty of Epidemiology and Population Health, Department of Infectious Disease Epidemiology, London School of Hygiene and Tropical Medicine (LSHTM), London, WC1E 7HT UK
- School of Pathology, Wits Institute for Malaria Research, Faculty of Health Science, University of Witwatersrand, Johannesburg, South Africa
| | - Umberto D’Alessandro
- Medical Research Council Unit The Gambia at London School of Hygiene and Tropical Medicine, Fajara, The Gambia
| | - Chris Drakeley
- Faculty of Infectious Tropical Diseases, Department of Infection Biology, London School of Hygiene and Tropical Medicine (LSHTM), London, WC1E 7HT UK
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13
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Abstract
The coherent and coordinated strategy put in place since the beginning of the century to fight malaria has led to a significant reduction in the global burden of the disease. Of the various elements composing this strategy, it appears that vector control and, in the first place, the massive distribution of LLIN (long-lasting impregnated nets) have contributed significantly to this success. The idea, a priori trivial, of impregnating nets with insecticide to make them more effective, emerged in the late 1980s in Benin. Since then, thanks to the ongoing support of WHO and collaboration with industry, there has been a paradigm shift that puts LLIN at the forefront of malaria control. This chapter summarizes, in chronological order, the different steps that led to the use of LLIN, starting with simple mosquito nets. It provides a brief overview of the studies that have shown their effectiveness both from the entomological and the morbidity and mortality point of view. Finally, it presents the limitations and challenges that will need to be overcome if LLIN are to remain an effective tool in the fight against malaria.
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Affiliation(s)
- Pierre Carnevale
- Institut de Recherche pour le Développement (IRD), Portiragnes, France
| | - Frédérick Gay
- UMR S 1136 équipe SUMO, Institut National de la Santé et de la Recherche Médicale (INSERM), Institut Pierre Louis d'Epidémiologie et de Santé Publique (iPLESP), Sorbonne Université, Paris, France.
- Assistance Publique Hôpitaux de Paris (AP-HP), Hôpital Pitié-Salpêtrière, Paris, France.
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14
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Jarvis CI, Multerer L, Lewis D, Binka F, Edmunds WJ, Alexander N, Smith TA. Spatial Effects of Permethrin-Impregnated Bed Nets on Child Mortality: 26 Years on, a Spatial Reanalysis of a Cluster Randomized Trial. Am J Trop Med Hyg 2020; 101:1434-1441. [PMID: 31595867 PMCID: PMC6896878 DOI: 10.4269/ajtmh.19-0111] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022] Open
Abstract
In addition to the direct effect of insecticide-treated nets (ITNs), there has been evidence for spatial indirect effects. Spatial analyses in cluster randomized trials (CRTs) are rare, but a large-scale CRT from 1993 was one of the first to conduct a spatial analysis of ITNs in CRTs. We revisit these data by applying a broader range of contemporary spatial methods to further explore spatial spillover. We conducted three analyses: 1) exploratory spatial analysis, considering spatial patterns and spillover in the data; 2) spatial modeling, estimating the intervention effect considering spatial effects; and 3) analysis of distance-based spillover and interaction with the intervention, characterizing the functional distance over which the spillover effect was present. There were consistent indications of spatial patterns from the exploratory analysis. Bed nets were associated with a 17% reduction in all-cause mortality for children aged 6-59 months, and the intervention estimate remained robust when allowing for the spatial structure of the data. There was strong evidence of a spatial spillover effect: for every additional 100 m that a control household was from an intervention household (and vice versa), the standardized mortality ratio (SMR) increased by 1.7% (SMR 1.017, 95% credible interval 1.006-1.026). Despite evidence of a spatial spillover effect, the conclusions of the trial remain unaffected by spatial model specifications. Use of ITNs was clearly beneficial for individuals, and there was compelling evidence that they provide an indirect benefit to individuals living nearby. This article demonstrates the extra utility that spatial methods can provide when analyzing a CRT.
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Affiliation(s)
- Christopher I Jarvis
- MRC London Hub for Trials Methodology Research, London, United Kingdom.,London School of Hygiene and Tropical Medicine, London, United Kingdom
| | - Lea Multerer
- University of Basel, Basel, Switzerland.,Department of Epidemiology and Public Health, Swiss Tropical and Public Health Institute, Basel, Switzerland
| | - Daniel Lewis
- London School of Hygiene and Tropical Medicine, London, United Kingdom
| | - Fred Binka
- School of Public Health, University of Health and Allied Sciences, Ho, Ghana
| | - W John Edmunds
- London School of Hygiene and Tropical Medicine, London, United Kingdom
| | - Neal Alexander
- London School of Hygiene and Tropical Medicine, London, United Kingdom
| | - Thomas A Smith
- University of Basel, Basel, Switzerland.,Department of Epidemiology and Public Health, Swiss Tropical and Public Health Institute, Basel, Switzerland
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15
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N'do S, Bayili K, Bayili B, Namountougou M, Sanou R, Ouattara A, Dabiré RK, Malone D, Ouédraogo AG, Borovsky J, Borovsky D, Diabaté A. Effect of Bacillus thuringiensis var. israelensis Sugar Patches on Insecticide Resistant Anopheles gambiae s.l. Adults. JOURNAL OF MEDICAL ENTOMOLOGY 2019; 56:1312-1317. [PMID: 31329914 DOI: 10.1093/jme/tjz058] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/23/2018] [Indexed: 06/10/2023]
Abstract
BACKGROUND Large distribution of long-lasting insecticidal nets (LLINs) and indoor residual spraying (IRS) contributed to a significant decrease in malarial mortality. Unfortunately, large insecticide resistance in malaria vectors occurred and is a threat to the future use of these control approaches. The purpose of this study was to explore a new approach for vector control. Patches containing Bacillus thuringiensis var. israelensis (Bti) solubilized Cry toxins mixed with sugar were developed and tested in the laboratory with pyrethroid-resistant Anopheles gambiae s.l. using tunnel tests. METHODS Mosquitoes were released at 6:00 p.m. into a large tunnel separated by a bed net, perforated with nine holes, from a smaller chamber with a guinea pig. Nine Bti sugar patches (BSPs) were attached to the bed net between the nine holes. Fourteen hours later (8:00 a.m.), mosquitoes were collected from the tunnel and the guinea pig chamber. Live females were kept in cups and were fed a sugar solution (5%) for 72 h and delayed mortality was followed. The results were reported as passing, blood fed and mortality rates. RESULTS Mosquito populations that are resistant to the insecticides in the bed net, exhibited high mortality (60%) in the presence of the BSPs. Untreated bed nets with patches in the tunnel test killed 66-95% of the mosquitoes that landed and untreated bed nets were superior to treated bed nets. CONCLUSION BSPs efficiently kill resistant mosquitoes that land on treated and untreated bed nets and thus could ultimately reduce the number of vector-borne malarial mosquitoes.
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Affiliation(s)
- Sévérin N'do
- Institut de Recherche en Sciences de la Santé/Centre Muraz, Bobo-Dioulasso, Ouagadougou, Burkina Faso
- Department of Tropical Diseases, Vector Control, Médecins Sans Frontières OCBA, Barcelona, Spain
| | - Koama Bayili
- Institut de Recherche en Sciences de la Santé/Centre Muraz, Bobo-Dioulasso, Ouagadougou, Burkina Faso
- Université Nazi Boni, Bobo-Dioulasso, Ouagadougou, Burkina Faso
| | - Bazoma Bayili
- Institut de Recherche en Sciences de la Santé/Centre Muraz, Bobo-Dioulasso, Ouagadougou, Burkina Faso
| | - Moussa Namountougou
- Institut de Recherche en Sciences de la Santé/Centre Muraz, Bobo-Dioulasso, Ouagadougou, Burkina Faso
- Université Nazi Boni, Bobo-Dioulasso, Ouagadougou, Burkina Faso
| | - Roger Sanou
- Institut de Recherche en Sciences de la Santé/Centre Muraz, Bobo-Dioulasso, Ouagadougou, Burkina Faso
| | - Abdoulaye Ouattara
- Institut de Recherche en Sciences de la Santé/Centre Muraz, Bobo-Dioulasso, Ouagadougou, Burkina Faso
| | - Roch K Dabiré
- Institut de Recherche en Sciences de la Santé/Centre Muraz, Bobo-Dioulasso, Ouagadougou, Burkina Faso
| | - David Malone
- Innovative Vector Control Consortium, Liverpool, United Kingdom
- Department of Vector Control, Sumitomo Chemical, Liverpool, United Kingdom
| | | | | | - Dov Borovsky
- Vector Busters International LLC, New Albany, OH
- Anschutz Medical School, Department of Biochemistry and Molecular Genetics, University of Colorado, Aurora, CO
| | - Abdoulaye Diabaté
- Institut de Recherche en Sciences de la Santé/Centre Muraz, Bobo-Dioulasso, Ouagadougou, Burkina Faso
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Malaria morbidity and mortality following introduction of a universal policy of artemisinin-based treatment for malaria in Papua, Indonesia: A longitudinal surveillance study. PLoS Med 2019; 16:e1002815. [PMID: 31167228 PMCID: PMC6541239 DOI: 10.1371/journal.pmed.1002815] [Citation(s) in RCA: 29] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/22/2018] [Accepted: 04/30/2019] [Indexed: 01/13/2023] Open
Abstract
BACKGROUND Malaria control activities can have a disproportionately greater impact on Plasmodium falciparum than on P. vivax in areas where both species are coendemic. We investigated temporal trends in malaria-related morbidity and mortality in Papua, Indonesia, before and after introduction of a universal, artemisinin-based antimalarial treatment strategy for all Plasmodium species. METHODS AND FINDINGS A prospective, district-wide malariometric surveillance system was established in April 2004 to record all cases of malaria at community clinics and the regional hospital and maintained until December 2013. In March 2006, antimalarial treatment policy was changed to artemisinin combination therapy for uncomplicated malaria and intravenous artesunate for severe malaria due to any Plasmodium species. Over the study period, a total of 418,238 patients presented to the surveillance facilities with malaria. The proportion of patients with malaria requiring admission to hospital fell from 26.9% (7,745/28,789) in the pre-policy change period (April 2004 to March 2006) to 14.0% (4,786/34,117) in the late transition period (April 2008 to December 2009), a difference of -12.9% (95% confidence interval [CI] -13.5% to -12.2%). There was a significant fall in the mortality of patients presenting to the hospital with P. falciparum malaria (0.53% [100/18,965] versus 0.32% [57/17,691]; difference = -0.21% [95% CI -0.34 to -0.07]) but not in patients with P. vivax malaria (0.28% [21/7,545] versus 0.23% [28/12,397]; difference = -0.05% [95% CI -0.20 to 0.09]). Between the same periods, the overall proportion of malaria due to P. vivax rose from 44.1% (30,444/69,098) to 53.3% (29,934/56,125) in the community clinics and from 32.4% (9,325/28,789) to 44.1% (15,035/34,117) at the hospital. After controlling for population growth and changes in treatment-seeking behaviour, the incidence of P. falciparum malaria fell from 511 to 249 per 1,000 person-years (py) (incidence rate ratio [IRR] = 0.49 [95% CI 0.48-0.49]), whereas the incidence of P. vivax malaria fell from 331 to 239 per 1,000 py (IRR = 0.72 [95% CI 0.71-0.73]). The main limitations of our study were possible confounding from changes in healthcare provision, a growing population, and significant shifts in treatment-seeking behaviour following implementation of a new antimalarial policy. CONCLUSIONS In this area with high levels of antimalarial drug resistance, adoption of a universal policy of efficacious artemisinin-based therapy for malaria infections due to any Plasmodium species was associated with a significant reduction in total malaria-attributable morbidity and mortality. The burden of P. falciparum malaria was reduced to a greater extent than that of P. vivax malaria. In coendemic regions, the timely elimination of malaria will require that safe and effective radical cure of both the blood and liver stages of the parasite is widely available for all patients at risk of malaria.
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17
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Salako AS, Ahogni I, Aïkpon R, Sidick A, Dagnon F, Sovi A, Sominahouin AA, Agossa F, Iyikirenga L, Akogbeto MC. Insecticide resistance status, frequency of L1014F Kdr and G119S Ace-1 mutations, and expression of detoxification enzymes in Anopheles gambiae (s.l.) in two regions of northern Benin in preparation for indoor residual spraying. Parasit Vectors 2018; 11:618. [PMID: 30509288 PMCID: PMC6278060 DOI: 10.1186/s13071-018-3180-2] [Citation(s) in RCA: 22] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/14/2018] [Accepted: 10/30/2018] [Indexed: 11/10/2022] Open
Abstract
BACKGROUND This study aims to provide baseline data on the resistance status to insecticides, the frequency of mechanisms involved and the impact of the association with the synergist piperonyl butoxide (PBO) on resistant Anopheles gambiae (s.l.) populations in two regions of northern Benin, prior to an indoor residual spraying campaign and introduction of next generation long-lasting insecticidal nets (LLINs) incorporating PBO. METHODS Adult Anopheles gambiae (s.l.) originating from larvae collected in two study regions (Alibori within the Kandi-Gogounou-Segbana districts and Donga within the Djougou-Copargo-Ouake districts) were tested with impregnated papers (bendiocarb 0.1%, pirimiphos-methyl 0.25%, permethrin 0.75% and deltamethrin 0.05%). The synergist PBO was used to check for the involvement of detoxification enzymes in pyrethroid resistant populations. Molecular analyses were performed for the identification of species within the Anopheles gambiae (s.l.) complex and kdr L1014F and G119S Ace-1 mutations. Biochemical assays assessed the activity of detoxification enzymes. RESULTS Anopheles gambiae (s.l.) was resistant to pyrethroids, with a mortality range of 25-83% with deltamethrin and 6-55% with permethrin. A significant increase in mortality was observed after pre-exposure to PBO for both deltamethrin (63-99%) and permethrin (56-99%). With bendiocarb, An. gambiae (s.l.) were susceptible in Kandi (99% mortality), with possible resistance (92-95%) recorded in Djougou, Copargo, Gogounou, Ouake and Segbana. All study populations were fully susceptible to pirimiphos-methyl. The frequencies of resistant mutations varied according to species and sites: 0.67-0.88 for L1014F kdr and 0-0.06 for G119S Ace-1. Three study locations (Djougou, Gogounou and Kandi) showed high oxidase activity and four sites (Djougou, Ouake, Copargo and Kandi) showed elevated esterase activity. CONCLUSIONS This study confirms resistance to pyrethroids and suggests emerging bendiocarb resistance in An. gambiae (s.l.) populations in northern Benin. However, recovery of susceptibility to pyrethroids after PBO exposure, and susceptibility to organophosphates in the An. gambiae (s.l.) populations indicate that next generation LLINs incorporating PBO synergist combined with an indoor residual spraying (IRS) campaign with organophosphate insecticides may be regarded as alternative control tools.
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Affiliation(s)
- Albert Sourou Salako
- Centre de Recherche entomologique de Cotonou (CREC), Cotonou, Benin. .,Faculté des Sciences et Techniques de l'Université d'Abomey-Calavi, Abomey-Calavi, Benin.
| | - Idelphonse Ahogni
- Centre de Recherche entomologique de Cotonou (CREC), Cotonou, Benin.,Faculté des Sciences et Techniques de l'Université d'Abomey-Calavi, Abomey-Calavi, Benin
| | - Rock Aïkpon
- Centre de Recherche entomologique de Cotonou (CREC), Cotonou, Benin.,Technologies, Ingénierie et Mathématiques, Université Nationale des Sciences, Abomey, Bénin
| | - Aboubakar Sidick
- Centre de Recherche entomologique de Cotonou (CREC), Cotonou, Benin
| | - Fortune Dagnon
- US Agency for International Development, US President's Malaria Initiative, Cotonou, Benin
| | - Arthur Sovi
- PMI VectorLink project, Abt associates, Bamako, Mali
| | - André Aimé Sominahouin
- Centre de Recherche entomologique de Cotonou (CREC), Cotonou, Benin.,Faculté des Sciences Humaines et Sociales de l'Université d'Abomey-Calavi, Abomey-Calavi, Benin
| | - Fiacre Agossa
- Centre de Recherche entomologique de Cotonou (CREC), Cotonou, Benin
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18
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Abstract
BACKGROUND A previous version of this Cochrane Review identified that insecticide-treated nets (ITNs) are effective at reducing child mortality, parasite prevalence, and uncomplicated and severe malaria episodes. Insecticide-treated nets have since become a core intervention for malaria control and have contributed greatly to the dramatic decline in disease incidence and malaria-related deaths seen since the turn of the millennium. However, this time period has also seen a rise in resistance to pyrethroids (the insecticide used in ITNs), raising questions over whether the evidence from trials conducted before resistance became widespread can be applied to estimate the impact of ITNs on malaria transmission today. OBJECTIVES The primary objective of this review was to assess the impact of ITNs on mortality and malaria morbidity, incorporating any evidence published since the previous update into new and existing analyses, and assessing the certainty of the resulting evidence using GRADE. SEARCH METHODS We searched the Cochrane Infectious Diseases Group Specialized Register, the Cochrane Central Register of Controlled Trials (CENTRAL) published in the Cochrane Library, MEDLINE, Embase, LILACS, the World Health Organization (WHO) International Clinical Trials Registry Platform, ClinicalTrials.gov, and the ISRCTN registry for new trials published since 2004 and up to 18 April 2018. SELECTION CRITERIA We included individual randomized controlled trials (RCTs) and cluster RCTs comparing bed nets or curtains treated with a synthetic pyrethroid insecticide at a minimum target impregnation dose recommended by the WHO with no nets or untreated nets. DATA COLLECTION AND ANALYSIS One review author assessed the identified trials for eligibility and risk of bias, and extracted data. We compared intervention and control data using risk ratios (RRs), rate ratios, and mean differences, and presented all results with their associated 95% confidence intervals (CIs). We assessed the certainty of evidence using the GRADE approach. We drew on evidence from a meta-analysis of entomological outcomes stratified by insecticide resistance from 2014 to inform the GRADE assessments. MAIN RESULTS Our updated search identified three new trials. A total of 23 trials met the inclusion criteria, enrolling more than 275,793 adults and children. The included studies were conducted between 1987 and 2001.ITN versus no netsInsecticide-treated nets reduce child mortality from all causes by 17% compared to no nets (rate ratio 0.83, 95% CI 0.77 to 0.89; 5 trials, 200,833 participants, high-certainty evidence). This corresponds to a saving of 5.6 lives (95% CI 3.6 to 7.6) each year for every 1000 children protected with ITNs. Insecticide-treated nets also reduce the incidence of uncomplicated episodes of Plasmodium falciparum malaria by almost a half (rate ratio 0.55, 95% CI 0.48 to 0.64; 5 trials, 35,551 participants, high-certainty evidence) and probably reduce the incidence of uncomplicated episodes of Plasmodium vivax malaria (risk ratio (RR) 0.61, 95% CI 0.48 to 0.77; 2 trials, 10,967 participants, moderate-certainty evidence).Insecticide-treated nets were also shown to reduce the prevalence of P falciparum malaria by 17% compared to no nets (RR 0.83, 95% CI 0.71 to 0.98; 6 trials, 18,809 participants, high-certainty evidence) but may have little or no effect on the prevalence of P vivax malaria (RR 1.00, 95% CI 0.75 to 1.34; 2 trials, 10,967 participants, low-certainty evidence). A 44% reduction in the incidence of severe malaria episodes was seen in the ITN group (rate ratio 0.56, 95% CI 0.38 to 0.82; 2 trials, 31,173 participants, high-certainty evidence), as well as an increase in mean haemoglobin (expressed as mean packed cell volume) compared to the no-net group (mean difference 1.29, 95% CI 0.42 to 2.16; 5 trials, 11,489 participants, high-certainty evidence).ITN versus untreated netsInsecticide-treated nets probably reduce child mortality from all causes by a third compared to untreated nets (rate ratio 0.67, 95% CI 0.36 to 1.23; 2 trials, 25,389 participants, moderate-certainty evidence). This corresponds to a saving of 3.5 lives (95% CI -2.4 to 6.8) each year for every 1000 children protected with ITNs. Insecticide-treated nets also reduce the incidence of uncomplicated P falciparum malaria episodes (rate ratio 0.58, 95% CI 0.44 to 0.78; 5 trials, 2036 participants, high-certainty evidence) and may also reduce the incidence of uncomplicated P vixax malaria episodes (rate ratio 0.73, 95% CI 0.51 to 1.05; 3 trials, 1535 participants, low-certainty evidence).Use of an ITN probably reduces P falciparum prevalence by one-tenth in comparison to use of untreated nets (RR 0.91, 95% CI 0.78 to 1.05; 3 trials, 2,259 participants, moderate-certainty evidence). However, based on the current evidence it is unclear whether or not ITNs impact on P vivax prevalence (1 trial, 350 participants, very low certainty evidence) or mean packed cell volume (2 trials, 1,909 participants, low certainty evidence). AUTHORS' CONCLUSIONS Although there is some evidence that insecticide resistance frequency has some effects on mosquito mortality, it is unclear how quantitatively important this is. It appeared insufficient to downgrade the strong evidence of benefit on mortality and malaria illness from the trials conducted earlier.
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Affiliation(s)
- Joseph Pryce
- Liverpool School of Tropical MedicineDepartment of Clinical SciencesPembroke PlaceLiverpoolUKL3 5QA
| | - Marty Richardson
- Liverpool School of Tropical MedicineDepartment of Clinical SciencesPembroke PlaceLiverpoolUKL3 5QA
| | - Christian Lengeler
- Swiss Tropical and Public Health InstitutePublic Health and EpidemiologyBaselSwitzerland4002
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19
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Wilson AL, Bradley J, Kandeh B, Salami K, D'Alessandro U, Pinder M, Lindsay SW. Is chronic malnutrition associated with an increase in malaria incidence? A cohort study in children aged under 5 years in rural Gambia. Parasit Vectors 2018; 11:451. [PMID: 30081945 PMCID: PMC6090805 DOI: 10.1186/s13071-018-3026-y] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/27/2018] [Accepted: 07/19/2018] [Indexed: 11/10/2022] Open
Abstract
Background Malnutrition is common in children in sub-Saharan Africa and is thought to increase the risk of infectious diseases, including malaria. The relationship between malnutrition and malaria was examined in a cohort of 6–59 month-old children in rural Gambia, in an area of seasonal malaria transmission. The study used data from a clinical trial in which a cohort of children was established and followed for clinical malaria during the 2011 transmission season. A cross-sectional survey to determine the prevalence of malaria and anaemia, and measure the height and weight of these children was carried out at the beginning and end of the transmission season. Standard anthropometric indices (stunting, wasting and underweight) were calculated using z-scores. Results At the beginning of the transmission season, 31.7% of children were stunted, 10.8% wasted and 24.8% underweight. Stunting was more common in Fula children than other ethnicities and in children from traditionally constructed houses compared to more modern houses. Stunted children and underweight children were significantly more likely to have mild or moderate anaemia. During the transmission season, 13.7% of children had at least one episode of clinical malaria. There was no association between stunting and malaria incidence (odds ratio = 0.79, 95% CI: 0.60–1.05). Malaria was not associated with differences in weight or height gain. Conclusions Chronic malnutrition remains a problem in rural Gambia, particularly among the poor and Fula ethnic group, but it was not associated with an increased risk of malaria. Trial registration Trial registration: ISRCTN, ISRCTN01738840, registered: 27/08/2010 (Retrospectively registered).
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Affiliation(s)
- Anne L Wilson
- Department of Biosciences, Durham University, Stockton Road, Durham, DH1 3LE, UK.
| | - John Bradley
- Medical Research Council Tropical Epidemiology Group, Department of Infectious Disease Epidemiology, Faculty of Epidemiology and Population Health, London School of Hygiene and Tropical Medicine, Keppel Street, London, WC1E 7HT, UK
| | - Ballah Kandeh
- National Malaria Control Programme, Banjul, The Gambia
| | - Kolawole Salami
- Medical Research Council Unit The Gambia at the London School of Hygiene and Tropical Medicine, Banjul, The Gambia
| | - Umberto D'Alessandro
- Medical Research Council Unit The Gambia at the London School of Hygiene and Tropical Medicine, Banjul, The Gambia.,Department of Disease Control, Faculty of Infectious and Tropical Diseases, London School of Hygiene and Tropical Medicine, Keppel Street, London, WC1E 7HT, UK
| | - Margaret Pinder
- Department of Biosciences, Durham University, Stockton Road, Durham, DH1 3LE, UK.,Medical Research Council Unit The Gambia at the London School of Hygiene and Tropical Medicine, Banjul, The Gambia
| | - Steven W Lindsay
- Department of Biosciences, Durham University, Stockton Road, Durham, DH1 3LE, UK.,Department of Disease Control, Faculty of Infectious and Tropical Diseases, London School of Hygiene and Tropical Medicine, Keppel Street, London, WC1E 7HT, UK
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20
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Silva BOD, Olivatti TOF, Kanda RG, Marco GND, Santaella FJ, Madeira NG, Haddad Junior V, Miot HA. Efficacy of the main repellents available in the Brazilian market against Aedes aegypti bites under concentrations applied to pediatric populations. Rev Soc Bras Med Trop 2018; 51:256-257. [PMID: 29768569 DOI: 10.1590/0037-8682-0438-2016] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/25/2017] [Accepted: 03/28/2018] [Indexed: 11/22/2022] Open
Affiliation(s)
- Bruna Oliveira da Silva
- Departamento de Dermatologia e Radioterapia, Faculdade de Medicina de Botucatu, Universidade Estadual Paulista, Botucatu, SP, Brasil
| | - Thainá Oliveira Felicio Olivatti
- Departamento de Dermatologia e Radioterapia, Faculdade de Medicina de Botucatu, Universidade Estadual Paulista, Botucatu, SP, Brasil
| | - Rafael Guimarães Kanda
- Departamento de Dermatologia e Radioterapia, Faculdade de Medicina de Botucatu, Universidade Estadual Paulista, Botucatu, SP, Brasil
| | - Gustavo Noé de Marco
- Departamento de Dermatologia e Radioterapia, Faculdade de Medicina de Botucatu, Universidade Estadual Paulista, Botucatu, SP, Brasil
| | - Felipe José Santaella
- Departamento de Dermatologia e Radioterapia, Faculdade de Medicina de Botucatu, Universidade Estadual Paulista, Botucatu, SP, Brasil
| | - Newton Goulart Madeira
- Departamento de Parasitologia, Instituto de Biociências, Universidade Estadual Paulista, Botucatu, SP, Brasil
| | - Vidal Haddad Junior
- Departamento de Dermatologia e Radioterapia, Faculdade de Medicina de Botucatu, Universidade Estadual Paulista, Botucatu, SP, Brasil
| | - Hélio Amante Miot
- Departamento de Dermatologia e Radioterapia, Faculdade de Medicina de Botucatu, Universidade Estadual Paulista, Botucatu, SP, Brasil
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21
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Mwesigwa J, Achan J, Di Tanna GL, Affara M, Jawara M, Worwui A, Hamid-Adiamoh M, Kanuteh F, Ceesay S, Bousema T, Drakeley C, Grietens KP, Lindsay SW, Van geertruyden JP, D’Alessandro U. Residual malaria transmission dynamics varies across The Gambia despite high coverage of control interventions. PLoS One 2017; 12:e0187059. [PMID: 29095834 PMCID: PMC5667860 DOI: 10.1371/journal.pone.0187059] [Citation(s) in RCA: 41] [Impact Index Per Article: 5.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/17/2017] [Accepted: 10/12/2017] [Indexed: 01/08/2023] Open
Abstract
Over the last decades, malaria has declined substantially in The Gambia but its transmission has not been interrupted. In order to better target control interventions, it is essential to understand the dynamics of residual transmission. This prospective cohort study was conducted between June 2013 and April 2014 in six pairs of villages across The Gambia. Blood samples were collected monthly during the transmission season (June-December) from all residents aged ≥6 months (4,194 individuals) and then in April (dry season). Entomological data were collected monthly throughout the malaria transmission season. Ownership of Long-Lasting Insecticidal Nets was 71.5% (2766/3869). Incidence of malaria infection and clinical disease varied significantly across the country, with the highest values in eastern (1.7/PYAR) than in central (0.2 /PYAR) and western (0.1/PYAR) Gambia. Malaria infection at the beginning of the transmission season was significantly higher in individuals who slept outdoors (HR = 1.51, 95% CI: 1.02-2.23, p = 0.04) and in those who had travelled outside the village (HR = 2.47, 95% CI: 1.83-3.34, p <0.01). Sub-patent infections were more common in older children (HR = 1.35, 95% CI: 1.04-1.6, p <0.01) and adults (HR = 1.53, 95% CI: 1.23-1.89, p<0.01) than in younger children. The risk of clinical malaria was significantly higher in households with at least one infected individual at the beginning of the transmission season (HR = 1.76, p<0.01). Vector parity was significantly higher in the eastern part of the country, both in the south (90.7%, 117/129, p<0.01) and the north bank (81.1%, 227/280, p<0.01), than in the western region (41.2%, 341/826), indicating higher vector survival. There is still significant residual malaria transmission across The Gambia, particularly in the eastern region. Additional interventions able to target vectors escaping Long-Lasting Insecticidal Nets and indoor residual spraying are needed to achieve malaria elimination.
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Affiliation(s)
- Julia Mwesigwa
- Medical Research Council Unit The Gambia, Banjul, The Gambia
- Department of Global Health, Faculty of Medicine and Health Sciences, University of Antwerp, Antwerp, Belgium
| | - Jane Achan
- Medical Research Council Unit The Gambia, Banjul, The Gambia
| | - Gian Luca Di Tanna
- Centre for Primary Care and Public Health, Queen Mary University of London, London, United Kingdom
| | - Muna Affara
- Medical Research Council Unit The Gambia, Banjul, The Gambia
| | - Musa Jawara
- Medical Research Council Unit The Gambia, Banjul, The Gambia
| | | | - Majidah Hamid-Adiamoh
- West African Centre for Cell Biology of Infectious Pathogens, Department of Biochemistry, Cell & Molecular Biology University of Ghana, Accra, Ghana
| | | | - Sainey Ceesay
- Medical Research Council Unit The Gambia, Banjul, The Gambia
| | - Teun Bousema
- Department of Medical Microbiology, Radboud University Medical Center, Nijmegen, The Netherlands
| | - Chris Drakeley
- Faculty of Infectious and Tropical Diseases, London School of Hygiene and Tropical Medicine, London, United Kingdom
| | - Koen Peeters Grietens
- Department of Public Health, Institute of Tropical Medicine, Antwerp, Belgium
- Amsterdam Institute for Social Science Research, University of Amsterdam, Amsterdam, The Netherlands
- School of Tropical Medicine and Global Health, Nagasaki University, Nagasaki, Japan
| | - Steve W. Lindsay
- School of Biological & Biomedical Sciences, Durham University, Durham, United Kingdom
| | - Jean-Pierre Van geertruyden
- Department of Global Health, Faculty of Medicine and Health Sciences, University of Antwerp, Antwerp, Belgium
| | - Umberto D’Alessandro
- Medical Research Council Unit The Gambia, Banjul, The Gambia
- Faculty of Infectious and Tropical Diseases, London School of Hygiene and Tropical Medicine, London, United Kingdom
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22
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Kesteman T, Randrianarivelojosia M, Rogier C. The protective effectiveness of control interventions for malaria prevention: a systematic review of the literature. F1000Res 2017; 6:1932. [PMID: 29259767 PMCID: PMC5721947 DOI: 10.12688/f1000research.12952.1] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Accepted: 10/27/2017] [Indexed: 12/22/2022] Open
Abstract
Background: Thanks to a considerable increase in funding, malaria control interventions (MCI) whose efficacy had been demonstrated by controlled trials have been largely scaled up during the last decade. Nevertheless, it was not systematically investigated whether this efficacy had been preserved once deployed on the field. Therefore, we sought the literature to assess the disparities between efficacy and effectiveness and the effort to measure the protective effectiveness (PE) of MCI. Methods: The PubMed database was searched for references with keywords related to malaria, to control interventions for prevention and to study designs that allow for the measure of the PE against parasitemia or against clinical outcomes. Results: Our search retrieved 1423 references, and 162 articles were included in the review. Publications were scarce before the year 2000 but dramatically increased afterwards. Bed nets was the MCI most studied (82.1%). The study design most used was a cross-sectional study (65.4%). Two thirds (67.3%) were conducted at the district level or below, and the majority (56.8%) included only children even if the MCI didn’t target only children. Not all studies demonstrated a significant PE from exposure to MCI: 60.6% of studies evaluating bed nets, 50.0% of those evaluating indoor residual spraying, and 4/8 showed an added PE of using both interventions as compared with one only; this proportion was 62.5% for intermittent preventive treatment of pregnant women, and 20.0% for domestic use of insecticides. Conclusions: This review identified numerous local findings of low, non-significant PE –or even the absence of a protective effect provided by these MCIs. The identification of such failures in the effectiveness of MCIs advocates for the investigation of the causes of the problem found. Ideal evaluations of the PE of MCIs should incorporate both a large representativeness and an evaluation of the PE stratified by subpopulations.
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Affiliation(s)
- Thomas Kesteman
- Fondation Mérieux, Lyon, France.,Malaria Research Unit, Institut Pasteur de Madagascar, Antananarivo, Madagascar
| | | | - Christophe Rogier
- Malaria Research Unit, Institut Pasteur de Madagascar, Antananarivo, Madagascar.,Ecole doctorale Sciences de la vie et de l'environnement, Université d'Antananarivo, Antananarivo, Madagascar.,Institute for Biomedical Research of the French Armed Forces (IRBA), Brétigny-Sur-Orge , France.,Unité de recherche sur les maladies infectieuses et tropicales émergentes - (URMITE), Marseille, France
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23
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Florey LS, Bennett A, Hershey CL, Bhattarai A, Nielsen CF, Ali D, Luhanga M, Taylor C, Eisele TP, Yé Y. Impact of Insecticide-Treated Net Ownership on All-Cause Child Mortality in Malawi, 2006-2010. Am J Trop Med Hyg 2017; 97:65-75. [PMID: 28990922 PMCID: PMC5619930 DOI: 10.4269/ajtmh.15-0929] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022] Open
Abstract
Insecticide-treated nets (ITNs) have been shown to be highly effective at reducing malaria morbidity and mortality in children. However, there are limited studies that assess the association between increasing ITN coverage and child mortality over time, at the national level, and under programmatic conditions. Two analytic approaches were used to examine this association: a retrospective cohort analysis of individual children and a district-level ecologic analysis. To evaluate the association between household ITN ownership and all-cause child mortality (ACCM) at the individual level, data from the 2010 Demographic and Health Survey (DHS) were modeled in a Cox proportional hazards framework while controlling for numerous environmental, household, and individual confounders through the use of exact matching. To evaluate population-level association between ITN ownership and ACCM between 2006 and 2010, program ITN distribution data and mortality data from the 2006 Multiple Indicator Cluster Survey and the 2010 DHS were aggregated at the district level and modeled using negative binomial regression. In the Cox model controlling for household, child and maternal health factors, children between 1 and 59 months in households owning an ITN had significantly lower mortality compared with those without an ITN (hazard ratio = 0.75, 95% confidence interval [CI] = 0.62–90). In the district-level model, higher ITN ownership was significantly associated with lower ACCM (incidence rate ratio = 0.77; 95% CI = 0.60–0.98). These findings suggest that increasing ITN ownership may have contributed to the decline in ACCM during 2006–2010 in Malawi and represent a novel use of district-level data from nationally representative surveys.
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Affiliation(s)
| | - Adam Bennett
- Malaria Elimination Initiative, University of California, San Francisco, California
| | - Christine L Hershey
- President's Malaria Initiative, United States Agency for International Development, Arlington, Virginia
| | - Achuyt Bhattarai
- President's Malaria Initiative, Malaria Branch, Centers for Disease Control and Prevention, Atlanta, Georgia
| | - Carrie F Nielsen
- President's Malaria Initiative, Malaria Branch, Centers for Disease Control and Prevention, Atlanta, Georgia
| | - Doreen Ali
- National Malaria Control Programme, Ministry of Health, Lilongwe, Malawi
| | - Misheck Luhanga
- National Malaria Control Programme, Ministry of Health, Lilongwe, Malawi
| | | | - Thomas P Eisele
- Center for Applied Malaria Research and Evaluation, School of Public Health and Tropical Medicine, Tulane University, New Orleans, Louisiana
| | - Yazoume Yé
- ICF, MEASURE Evaluation, Rockville, Maryland
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24
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Wang X, Zhao XQ. A climate-based malaria model with the use of bed nets. J Math Biol 2017; 77:1-25. [PMID: 28965238 DOI: 10.1007/s00285-017-1183-9] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/16/2016] [Revised: 05/03/2017] [Indexed: 11/26/2022]
Abstract
Insecticide-treated bed nets (ITNs) are among the most important and effective intervention measures against malaria. In order to investigate the impact of bed net use on disease control, we formulate a periodic vector-bias malaria model incorporating the juvenile stage of mosquitoes and the use of ITNs. We derive the vector reproduction ratio [Formula: see text] and the basic reproduction ratio [Formula: see text]. We show that the global dynamics of the model is completely determined by these two reproduction ratios. More precisely, the mosquito-free periodic solution is globally attractive if [Formula: see text]; the unique disease-free periodic solution is globally attractive if [Formula: see text] and [Formula: see text]; and the model admits a unique positive periodic solution and it is globally attractive if [Formula: see text] and [Formula: see text]. Numerically, we study the malaria transmission case in Port Harcourt, Nigeria. Our findings show that the use of ITNs has a positive effect on reducing [Formula: see text], and that malaria may be eliminated from this area if over 75% of the human population were to use ITNs. The simulation about the long term behavior of solutions has good agreement with the obtained analytic result. Moreover, we find that the ignorance of the vector-bias effect may result in underestimation of the basic reproduction ratio [Formula: see text]. Another notable result is that the infection risk would be underestimated if the basic reproduction ratio [Formula: see text] of the time-averaged autonomous system were used.
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Affiliation(s)
- Xiunan Wang
- Department of Mathematics and Statistics, Memorial University of Newfoundland, St. John's, NL, A1C 5S7, Canada.
| | - Xiao-Qiang Zhao
- Department of Mathematics and Statistics, Memorial University of Newfoundland, St. John's, NL, A1C 5S7, Canada
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25
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Stobaugh HC, Bollinger LB, Adams SE, Crocker AH, Grise JB, Kennedy JA, Thakwalakwa C, Maleta KM, Dietzen DJ, Manary MJ, Trehan I. Effect of a package of health and nutrition services on sustained recovery in children after moderate acute malnutrition and factors related to sustaining recovery: a cluster-randomized trial. Am J Clin Nutr 2017; 106:657-666. [PMID: 28615258 PMCID: PMC6482975 DOI: 10.3945/ajcn.116.149799] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/21/2016] [Accepted: 05/15/2017] [Indexed: 11/14/2022] Open
Abstract
Background: Children who recover from moderate acute malnutrition (MAM) have high rates of relapse in the year after nutritional recovery. Interventions to decrease these adverse outcomes are needed to maximize the overall effectiveness of supplemental feeding programs (SFPs).Objective: We evaluated the effectiveness of a package of health and nutrition interventions on improving the proportion of children who sustained recovery for 1 y after MAM treatment. We further explored factors related to sustained recovery.Design: We conducted a cluster-randomized clinical effectiveness trial involving rural Malawian children aged 6-62 mo who were enrolled on discharge from an SFP for MAM. We enrolled 718 children at 10 control sites and 769 children at 11 intervention sites. In addition to routine health and nutrition counseling, the intervention group received a package of health and nutrition interventions that consisted of a lipid nutrient supplement, deworming medication, zinc supplementation, a bed net, and malaria chemoprophylaxis. A survival analysis was used to determine the effectiveness of the intervention as well as to identify factors associated with sustained recovery.Results: Of 1383 children who returned for the full 12-mo follow-up period, 407 children (56%) and 347 children (53%) sustained recovery in the intervention and control groups, respectively. There was no significant difference in relapse-free survival curves between the treatment and control groups (P = 0.380; log-rank test). The risk factors for relapse or death after initial recovery were a smaller midupper arm circumference on SFP admission (P = 0.01) and discharge (P < 0.001), a lower weight-for-height z score on discharge (P < 0.01), and the receipt of ready-to-use supplementary food as opposed to ready-to-use therapeutic food during treatment (P < 0.05).Conclusion: The provision of a package of health and nutrition services in addition to traditional SFP treatment has no significant effect on improving sustained recovery in children after treatment of MAM. This trial was registered at clinicaltrials.gov as NCT02351687.
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Affiliation(s)
- Heather C Stobaugh
- Friedman School of Nutrition Science and Policy, Tufts University, Boston, MA
- Department of Pediatrics, Washington University in St. Louis, St. Louis, MO
| | - Lucy B Bollinger
- Department of Pediatrics, Washington University in St. Louis, St. Louis, MO
| | - Sara E Adams
- Department of Pediatrics, Washington University in St. Louis, St. Louis, MO
| | - Audrey H Crocker
- Department of Pediatrics, Washington University in St. Louis, St. Louis, MO
| | - Jennifer B Grise
- Department of Pediatrics, Washington University in St. Louis, St. Louis, MO
| | - Julie A Kennedy
- Department of Pediatrics, Washington University in St. Louis, St. Louis, MO
| | | | | | - Dennis J Dietzen
- Department of Pediatrics, Washington University in St. Louis, St. Louis, MO
| | - Mark J Manary
- Department of Pediatrics, Washington University in St. Louis, St. Louis, MO
- School of Public Health and Family Medicine and
- Children's Nutrition Research Center, Baylor College of Medicine, Houston, TX; and
| | - Indi Trehan
- Department of Pediatrics, Washington University in St. Louis, St. Louis, MO;
- Department of Pediatrics and Child Health, University of Malawi, Blantyre, Malawi
- Partners In Health, Harper, Liberia
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Alout H, Labbé P, Chandre F, Cohuet A. Malaria Vector Control Still Matters despite Insecticide Resistance. Trends Parasitol 2017; 33:610-618. [PMID: 28499699 DOI: 10.1016/j.pt.2017.04.006] [Citation(s) in RCA: 35] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/10/2017] [Revised: 04/14/2017] [Accepted: 04/18/2017] [Indexed: 11/26/2022]
Abstract
Mosquito vectors' resistance to insecticides is usually considered a major threat to the recent progresses in malaria control. However, studies measuring the impact of interventions and insecticide resistance reveal inconsistencies when using entomological versus epidemiological indices. First, evaluation tests that do not reflect the susceptibility of mosquitoes when they are infectious may underestimate insecticide efficacy. Moreover, interactions between insecticide resistance and vectorial capacity reveal nonintuitive outcomes of interventions. Therefore, considering ecological interactions between vector, parasite, and environment highlights that the impact of insecticide resistance on the malaria burden is not straightforward and we suggest that vector control still matters despite insecticide resistance.
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Affiliation(s)
- Haoues Alout
- Institut des Sciences de l'Evolution de Montpellier, CNRS, IRD, University of Montpellier, ISEM - UMR 5554, Montpellier, France.
| | - Pierrick Labbé
- Institut des Sciences de l'Evolution de Montpellier, CNRS, IRD, University of Montpellier, ISEM - UMR 5554, Montpellier, France
| | - Fabrice Chandre
- Institut de recherche pour le développement (IRD), Maladies Infectieuses et Vecteurs, Ecologie, Génétique, Evolution et Contrôle (MIVEGEC), UM-CNRS 5290 IRD 224, Montpellier, France
| | - Anna Cohuet
- Institut de recherche pour le développement (IRD), Maladies Infectieuses et Vecteurs, Ecologie, Génétique, Evolution et Contrôle (MIVEGEC), UM-CNRS 5290 IRD 224, Montpellier, France.
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Hien AS, Soma DD, Hema O, Bayili B, Namountougou M, Gnankiné O, Baldet T, Diabaté A, Dabiré KR. Evidence that agricultural use of pesticides selects pyrethroid resistance within Anopheles gambiae s.l. populations from cotton growing areas in Burkina Faso, West Africa. PLoS One 2017; 12:e0173098. [PMID: 28253316 PMCID: PMC5333875 DOI: 10.1371/journal.pone.0173098] [Citation(s) in RCA: 54] [Impact Index Per Article: 7.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/03/2016] [Accepted: 02/15/2017] [Indexed: 11/19/2022] Open
Abstract
Many studies have shown the role of agriculture in the selection and spread of resistance of Anopheles gambiae s.l. to insecticides. However, no study has directly demonstrated the presence of insecticides in breeding sources as a source of selection for this resistance. It is in this context that we investigated the presence of pesticide residues in breeding habitats and their formal involvement in vector resistance to insecticides in areas of West Africa with intensive farming. This study was carried out from June to November 2013 in Dano, southwest Burkina Faso in areas of conventional (CC) and biological cotton (BC) growing. Water and sediment samples collected from breeding sites located near BC and CC fields were submitted for chromatographic analysis to research and titrate the residual insecticide content found there. Larvae were also collected in these breeding sites and used in toxicity tests to compare their mortality to those of the susceptible strain, Anopheles gambiae Kisumu. All tested mosquitoes (living and dead) were analyzed by PCR for species identification and characterization of resistance genes. The toxicity analysis of water from breeding sites showed significantly lower mortality rates in breeding site water from biological cotton (WBC) growing sites compared to that from conventional cotton (WCC) sites respective to both An. gambiae Kisumu (WBC: 80.75% vs WCC: 92.75%) and a wild-type strain (49.75% vs 66.5%). The allele frequencies L1014F, L1014S kdr, and G116S ace -1R mutations conferring resistance, respectively, to pyrethroids and carbamates / organophosphates were 0.95, 0.4 and 0.12. Deltamethrin and lambda-cyhalothrin were identified in the water samples taken in October/November from mosquitoes breeding in the CC growing area. The concentrations obtained were respectively 0.0147ug/L and 1.49 ug/L to deltamethrin and lambdacyhalothrin. Our results provided evidence by direct analysis (biological and chromatographic tests) of the role of agriculture as a source of selection pressure on vectors to insecticides used in growing areas.
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Affiliation(s)
- Aristide Sawdetuo Hien
- IRSS/DRO, Malaria and Tropical Neglected Research Unit, Bobo-Dioulasso, Burkina Faso
- * E-mail: (ASH); (KRD)
| | - Dieudonné Diloma Soma
- IRSS/DRO, Malaria and Tropical Neglected Research Unit, Bobo-Dioulasso, Burkina Faso
| | - Omer Hema
- Programme Coton/INERA/ Farako-Ba, Bobo-Dioulasso, Burkina Faso
| | - Bazoma Bayili
- IRSS/DRO, Malaria and Tropical Neglected Research Unit, Bobo-Dioulasso, Burkina Faso
| | - Moussa Namountougou
- Institute of Rural Development, Université Polytechnique de Bobo-Dioulasso, Burkina Faso
| | - Olivier Gnankiné
- UFR/Life Science, Université Joseph Ki-Zerbo, Ouagadougou, Burkina Faso
| | | | - Abdoulaye Diabaté
- IRSS/DRO, Malaria and Tropical Neglected Research Unit, Bobo-Dioulasso, Burkina Faso
| | - Kounbobr Roch Dabiré
- IRSS/DRO, Malaria and Tropical Neglected Research Unit, Bobo-Dioulasso, Burkina Faso
- * E-mail: (ASH); (KRD)
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Molineaux L. Malaria and mortality: some epidemiological considerations. ANNALS OF TROPICAL MEDICINE AND PARASITOLOGY 2016. [DOI: 10.1080/00034983.1997.11813207] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/28/2022]
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Forastiere L, Mealli F, VanderWeele TJ. Identification and Estimation of Causal Mechanisms in Clustered Encouragement Designs: Disentangling Bed Nets using Bayesian Principal Stratification. J Am Stat Assoc 2016; 111:510-525. [PMID: 28008210 DOI: 10.1080/01621459.2015.1125788] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/22/2022]
Abstract
Exploration of causal mechanisms is often important for researchers and policymakers to understand how an intervention works and how it can be improved. This task can be crucial in clustered encouragement designs (CED). Encouragement design studies arise frequently when the treatment cannot be enforced because of ethical or practical constrains and an encouragement intervention (information campaigns, incentives, etc) is conceived with the purpose of increasing the uptake of the treatment of interest. By design, encouragements always entail the complication of non-compliance. Encouragements can also give rise to a variety of mechanisms, particularly when encouragement is assigned at cluster level. Social interactions among units within the same cluster can result in spillover effects. Disentangling the effect of encouragement through spillover effects from that through the enhancement of the treatment would give better insight into the intervention and it could be compelling for planning the scaling-up phase of the program. Building on previous works on CEDs and non-compliance, we use the principal stratification framework to define stratum-specific causal effects, that is, effects for specific latent subpopulations, defined by the joint potential compliance statuses under both encouragement conditions. We show how the latter stratum-specific causal effects are related to the decomposition commonly used in the literature and provide flexible homogeneity assumptions under which an extrapolation across principal strata allows one to disentangle the effects. Estimation of causal estimands can be performed with Bayesian inferential methods using hierarchical models to account for clustering. We illustrate the proposed methodology by analyzing a cluster randomized experiment implemented in Zambia and designed to evaluate the impact on malaria prevalence of an agricultural loan program intended to increase the bed net coverage. Farmer households assigned to the program could take advantage of a deferred payment and a discount in the purchase of new bed nets. Our analysis shows a lack of evidence of an effect of the offering of the program to a cluster of households through spillover effects, that is through a greater bed net coverage in the neighborhood.
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Laopaiboon M. Meta-analyses involving cluster randomization trials: a review of published literature in health care. Stat Methods Med Res 2016; 12:515-30. [PMID: 14653354 DOI: 10.1191/0962280203sm347oa] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/05/2022]
Abstract
Throughout the 1980s and 1990s cluster randomization trials have been increasingly used to evaluate effectivenessof health care intervention. Such trials have raised several methodologic challenges in analysis. Meta-analyses involving cluster randomization trials are becoming common in the area of health care intervention. However, as yet there has been no empirical evidence of current practice in the meta-analyses. Thus a review was performed to identify and examine synthesis approaches of meta-analyses involving cluster randomization trials in the published literature. Electronic databases were searched for meta-analyses involving cluster randomization trials from the earliest date available to 2000. Once a meta-analysis was identified, papers on the relevant cluster randomization trials included were also requested. Each of the original papers of cluster randomization trials included was examined for its randomized design and unit, and adjustment for clustering effect in analysis. Each of the selected meta-analyses was then evaluated as to its synthesis concerning clustering effect. In total, 25 eligible meta-analyses were reviewed. Of these, 15 meta-analyses reported simple conventional methods of the fixed-effect model as method of analysis, while six did not incorporate the cluster randomization trial results in the synthesis methods but described the trial results individually. Three meta-analyses attempted to account for the clustering effect in the synthesis methods but approaches were in arbitrary. Fifteen meta-analyses included more than one cluster randomization trial, each of which included cluster randomization trials with a mixture of randomized designs and units, and units of analysis. These mixture situations might increase heterogeneity, but have not been considered in any meta-analysis. Some methods dealing with a binary outcome for some specific situations have been discussed. In conclusion, some difficulties in the quantitative synthesis procedures were found in the meta-analyses involving cluster randomization trials. Recommendations in the applications of approaches to some specific situations in a binary outcome variable have also been provided. There are still, however, several methodologic issues of the meta-analyses involving cluster randomization trials that need to be investigated further.
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Affiliation(s)
- M Laopaiboon
- Department of Biostatistics and Demography, Khon Kaen University, Khon Kaen, Thailand.
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Song JS, Paul MM, Dhakal S, Smith MK, Michel MK, Cha E, Nam EW. Analysis of Insecticide-Treated Net Use by Pregnant Women: Implications for Donor Organizations. J Lifestyle Med 2016; 6:36-42. [PMID: 27358838 PMCID: PMC4915765 DOI: 10.15280/jlm.2016.6.1.36] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/07/2015] [Accepted: 01/08/2016] [Indexed: 11/22/2022] Open
Abstract
BACKGROUND The World Health Organization (WHO) recommends the use of insecticide-treated nets (ITNs) for the prevention of malaria and reduction of mortality and morbidity from mosquito-borne diseases. Although many countries, including the Democratic Republic of Congo, have adopted this recommendation and distributed bed nets to their inhabitants, the percentage of the population using ITNs remains low. METHODS This study was conducted with 400 mothers with at least one child under 5 years of age in health zones in the Bandundu province. Face-to-face interviews were conducted using structured pre-coded questionnaires. Chi-square tests and logistic regressions were calculated using the SPSS Version 21.0 software. RESULTS Among the studied variables, education status (p = 0.013), marital status (p = 0.004), ANC utilization (p = 0.13), suffering from malaria during pregnancy (p = 0.019), and knowledge of the seriousness of malaria (p = 0.013) were significant determinants of the use of ITNs in logistic regression analyses. CONCLUSION The results of this study indicate that the regular use of ITNs by women during pregnancy is associated with marital status, attending ANC services, and awareness of the serious nature of malaria. Therefore, education about the risk factors among populations is needed.
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Affiliation(s)
- Jin Sung Song
- Department of Health Administration, Graduate School, Yonsei University, Wonju, Korea; Yonsei Global Health Center, Yonsei University, Wonju, Korea; Socio-Economic Development Department, Korea International Cooperation Agency, Seongnam, Korea
| | - Mansiangi Mankadi Paul
- School of Public Health, University of Kinshasa, Kinshasa, Democratic Republic of the Congo
| | - Sarita Dhakal
- Department of Health Administration, Graduate School, Yonsei University, Wonju, Korea; Yonsei Global Health Center, Yonsei University, Wonju, Korea
| | - Mpaka Kiansiku Smith
- Public Health Research and Action Centre (CRASP), Kongo University, Mbanza-Ngungu, Democratic Republic of the Congo
| | | | - Eunju Cha
- Socio-Economic Development Department, Korea International Cooperation Agency, Seongnam, Korea
| | - Eun Woo Nam
- Department of Health Administration, Graduate School, Yonsei University, Wonju, Korea; Yonsei Global Health Center, Yonsei University, Wonju, Korea
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Chen I, Clarke SE, Gosling R, Hamainza B, Killeen G, Magill A, O’Meara W, Price RN, Riley EM. "Asymptomatic" Malaria: A Chronic and Debilitating Infection That Should Be Treated. PLoS Med 2016; 13:e1001942. [PMID: 26783752 PMCID: PMC4718522 DOI: 10.1371/journal.pmed.1001942] [Citation(s) in RCA: 230] [Impact Index Per Article: 28.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/16/2023] Open
Abstract
Roland Gosling and colleagues argue that "asymptomatic" malaria infections have significant health and societal consequences, and propose that they should be renamed "chronic" malaria infections.
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Affiliation(s)
- Ingrid Chen
- Global Health Sciences, Malaria Elimination Initiative, University of California, San Francisco, San Francisco, California, United States of America
| | - Siân E. Clarke
- Department of Disease Control, Faculty of Infectious and Tropical Diseases, London School of Hygiene & Tropical Medicine, London, United Kingdom
| | - Roly Gosling
- Global Health Sciences, Malaria Elimination Initiative, University of California, San Francisco, San Francisco, California, United States of America
- * E-mail:
| | - Busiku Hamainza
- Ministry of Health, National Malaria Control Centre, Lusaka, Zambia
| | - Gerry Killeen
- Liverpool School of Tropical Medicine, Vector Biology Department, Liverpool, United Kingdom
- Ifakara Health Institute, Ifakara, Morogoro, United Republic of Tanzania
| | - Alan Magill
- Bill & Melinda Gates Foundation, Seattle, Washington, United States of America
| | - Wendy O’Meara
- Duke Global Health Institute, Duke University, Durham, North Carolina, United States of America
| | - Ric N. Price
- Global and Tropical Health Division, Menzies School of Health Research and Charles Darwin University, Darwin, Australia
- Centre for Tropical Medicine and Global Health, Nuffield Department of Clinical Medicine, University of Oxford, Oxford, United Kingdom
| | - Eleanor M. Riley
- Department of Immunology and Infection, Faculty of Infectious and Tropical Diseases, London School of Hygiene & Tropical Medicine, London, United Kingdom
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Mwesigwa J, Okebe J, Affara M, Di Tanna GL, Nwakanma D, Janha O, Opondo K, Grietens KP, Achan J, D'Alessandro U. On-going malaria transmission in The Gambia despite high coverage of control interventions: a nationwide cross-sectional survey. Malar J 2015; 14:314. [PMID: 26268225 PMCID: PMC4535679 DOI: 10.1186/s12936-015-0829-6] [Citation(s) in RCA: 66] [Impact Index Per Article: 7.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/30/2015] [Accepted: 08/03/2015] [Indexed: 11/13/2022] Open
Abstract
Background As indicators of burden of malaria have substantially decreased in The Gambia, reaching a pre-elimination status may be attainable. Achieving this goal requires in-depth understanding of the current burden of Plasmodium falciparum infection. Methods A nationwide cross-sectional survey was conducted in 2012 to determine the prevalence of P.falciparum infection, and to describe its heterogeneity and associated risk factors. Finger-prick blood samples were collected for microscopy, species-specific PCR and haemoglobin measurement. Results A total of 9,094 participants were included and median
age was 11.9 years (IQR 5, 28). Overall prevalence of P. falciparum was 16.01 % with marked heterogeneity between sites (4.32–36.75 %) and within villages in each site (1.63–49.13 %). Across all sites, 51.17 % (745/1,456) of infections were asymptomatic and 35.61 % (448/1,258) were sub-microscopic. The odds of P. falciparum infection were higher in older children; 5–15 years (OR = 1.90; 95 % CI 1.60–2.26), adults (OR = 1.48; 95 % CI 1.24–1.78) and participants with moderate anaemia (OR = 1.62; 95 % CI 1.32–1.99). Conclusions The current malaria control interventions are not sufficient to interrupt transmission in The Gambia as malaria prevalence is still relatively high in the eastern part of the country. New interventions aiming at interrupting transmission are needed and should be urgently evaluated.
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Affiliation(s)
- Julia Mwesigwa
- Medical Research Council Unit, PO Box 273, Banjul, The Gambia.
| | - Joseph Okebe
- Medical Research Council Unit, PO Box 273, Banjul, The Gambia.
| | - Muna Affara
- Medical Research Council Unit, PO Box 273, Banjul, The Gambia.
| | | | - Davis Nwakanma
- Medical Research Council Unit, PO Box 273, Banjul, The Gambia.
| | - Omar Janha
- Medical Research Council Unit, PO Box 273, Banjul, The Gambia.
| | - Kevin Opondo
- Medical Research Council Unit, PO Box 273, Banjul, The Gambia.
| | - Koen Peeters Grietens
- Institute of Tropical Medicine, Antwerp, Belgium. .,School of International Health Development, Nagasaki University, Nagasaki, Japan. .,Partners for Applied Social Sciences (PASS) International, Tessenderlo, Belgium.
| | - Jane Achan
- Medical Research Council Unit, PO Box 273, Banjul, The Gambia.
| | - Umberto D'Alessandro
- Medical Research Council Unit, PO Box 273, Banjul, The Gambia. .,London School of Hygiene and Tropical Medicine, London, UK. .,Institute of Tropical Medicine, Antwerp, Belgium.
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Whidden CE, Premaratne RG, Jayanetti SR, Fernando SD. Patterns and predictive factors of long-lasting insecticidal net usage in a previously high malaria endemic area in Sri Lanka: a cross-sectional survey. Trans R Soc Trop Med Hyg 2015; 109:553-62. [PMID: 26187622 DOI: 10.1093/trstmh/trv056] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/10/2015] [Accepted: 06/25/2015] [Indexed: 11/12/2022] Open
Abstract
BACKGROUND Long-lasting insecticidal nets (LLINs) have been widely distributed in Sri Lanka for malaria control. Their effectiveness depends on proper utilisation and maintenance at the household level. METHODS A cross-sectional study was performed to examine the patterns and predictive factors of LLIN maintenance and use in Anuradhapura district. Data was collected and analysed from 530 LLIN-owning households, selected by a multi-stage cluster sampling technique. Multivariable logistic regression identified factors associated with proper maintenance at the household level. Hierarchical linear modelling identified factors associated with LLIN use the previous night. RESULTS Almost 75% (377/504) of households had used all their LLINs the previous night, while 82.9% (418/504) had used at least one. Only 3.2% (15/474) were maintaining the LLIN in such a way as to maximise its insecticidal efficacy. Six variables were significantly associated (p<0.05) with use the previous night: more residents, fewer plain nets, reporting practical benefits of LLINs, conical shape, newer nets and lack of side effects. Two variables were significantly associated with proper maintenance: increasing level of education and taking safety precautions while washing. CONCLUSIONS Results suggest LLIN practices could improve in settings of low malaria transmission if distribution programmes took into account recipient preferences, promoted LLIN use over plain nets, and emphasised the techniques and significance of proper net maintenance.
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Affiliation(s)
| | | | | | - S Deepika Fernando
- Department of Parasitology, Faculty of Medicine, P.O. Box 271, Kynsey Road, Colombo 8, Sri Lanka
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The implication of long-lasting insecticide-treated net use in the resurgence of malaria morbidity in a Senegal malaria endemic village in 2010-2011. Parasit Vectors 2015; 8:267. [PMID: 25963402 PMCID: PMC4489109 DOI: 10.1186/s13071-015-0871-9] [Citation(s) in RCA: 21] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/21/2014] [Accepted: 04/23/2015] [Indexed: 11/10/2022] Open
Abstract
BACKGROUND Although the burden of malaria has significantly declined in recent years in sub-Saharan Africa through the widespread use of long-lasting insecticide treated bed-nets (LLINs) and artemisinin-based combination therapy, resurgence of malaria is observed in some settings after several years of LLINs use. This study aimed to assess if LLINs use remains protective against malaria during a period of resurgence of malaria morbidity in Dielmo, a rural village of Senegal. METHODS In July 2008, LLINs were offered to all villagers and lately in July 2011, LLINs were renewed. A longitudinal study was conducted between July, 2010 and December, 2011 among inhabitants of the village of Dielmo to identify all episodes of fever. Thick smears stained with Giemsa were done for every febrile villager and malaria attacks were treated with combination of Artesunate plus Amodiaquine. Cross-sectional surveys were also conducted at the end of the rainy season (October 2010 and November 2011) to assess asymptomatic carriage. A survey on LLINs use was done every quarter of the year. A random-effect logistic regression was used to assess the effect of LLINs use on the risk of having a malaria attack after adjusting for the main risk factors. RESULTS The study population included 449 individuals corresponding to a total of 2140 observations. One hundred and fifteen (115) clinical malaria attacks attributed to P. falciparum (cases) have been recorded over the study period. Most of the malaria cases occurred in October-December 2010 (49/115 i.e. 43%) and among adults aged 15 years and over (50/115, i.e. 43%). During the study period, the use of LLINs was 61% among non-malaria cases and only 42% among malaria clinical cases but differenced according to age group. After adjusting on gender, age, rainfall and LLINs replacement, we found that LLINs use (AOR [95%CI] = 0.40 [0.25; 0.62], p < 0.001) remained a protective factor against malaria attacks during the study period. CONCLUSION LLINs use remains effective to reduce malaria burden. These results highlight the need to pursue LLINs implementation in the current context of malaria elimination and to provide positive incentives to increase its use in the population.
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The relationship between Plasmodium infection, anaemia and nutritional status in asymptomatic children aged under five years living in stable transmission zones in Kinshasa, Democratic Republic of Congo. Malar J 2015; 14:83. [PMID: 25880427 PMCID: PMC4336722 DOI: 10.1186/s12936-015-0595-5] [Citation(s) in RCA: 30] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/03/2014] [Accepted: 01/30/2015] [Indexed: 11/10/2022] Open
Abstract
BACKGROUND Malaria is preventable and treatable when recommended interventions are properly implemented. Thus, diagnosis and treatment focus on symptomatic individuals while asymptomatic Plasmodium infection (PI) plays a role in the sustainability of the transmission and may also have an impact on the morbidity of the disease in terms of anaemia, nutritional status and even cognitive development of children. The objective of this study was to assess PI prevalence and its relationship with known morbidity factors in a vulnerable but asymptomatic stratum of the population. METHODS A simple random sample, household survey in asymptomatic children under the age of five was conducted from April to September 2012 in two health areas of the health zone of Mont Ngafula 1, Kinshasa, Democratic Republic of Congo. RESULTS The PI prevalence were 30.9% (95% CI: 26.5-35.9) and 14.3% (95% CI: 10.5-18.1) in Cité Pumbu and Kindele health areas, respectively, (OR: 2.7; p <0.001). All were Plasmodium falciparum infected and 4% were co-infected with Plasmodium malariae. In Cité Pumbu and Kindele, the prevalence of anaemia (haemoglobin <11 g/dL) was 61.6% (95% CI: 56.6-66.5) and 39.3% (95% CI: 34.0-44.6), respectively, (OR: 2.5; p <0.001). The health area of Cité Pumbu had 32% (95% CI: 27.5-37.0) of chronic malnutrition (HAZ score ≤ -2SD) compared to 5.1% (95% CI: 2.8-7.6) in Kindele. PI was predictor factor for anaemia (aOR: 3.5, p =0.01) and within infected children, there was an inverse relationship between parasite density and haemoglobin level (β = -5*10(-5), p <0.001). Age older than 12 months (aOR: 3.8, p = 0.01), presence of anaemia (aOR: 3.4, p =0.001), chronic malnutrition (aOR: 1.8, p = 0.01), having a single parent/guardian (aOR: 1.6, p =0.04), and the non-use of insecticide-treated nets (aOR: 1.7, p = 0.04) were all predictors for PI in the overall population. CONCLUSION PI in asymptomatic children was correlated with anaemia and chronic malnutrition and was thus a harmful condition in the study population. Malaria control initiatives should not only focus on treatment of symptomatic infections but also take into consideration asymptomatic but infected children.
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Synergistic and antagonistic interactions between bednets and vaccines in the control of malaria. Proc Natl Acad Sci U S A 2015; 112:3014-9. [PMID: 25605894 DOI: 10.1073/pnas.1409467112] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
It is extremely likely that the malaria vaccines currently in development will be used in conjunction with treated bednets and other forms of malaria control. The interaction of different intervention methods is at present poorly understood in a disease such as malaria where immunity is more complex than for other pathogens that have been successfully controlled by vaccination. Here we develop a general mathematical model of malaria transmission to examine the interaction between vaccination and bednets. Counterintuitively, we find that the frailty of malaria immunity will potentially cause both synergistic and antagonistic interactions between vaccination and the use of bednets. We explore the conditions that create these tensions, and outline strategies that minimize their detrimental impact. Our analysis specifically considers the three leading vaccine classes currently in development: preerythrocytic (PEV), blood stage (BSV), and transmission blocking (TBV). We find that the combination of BSV with treated bednets can lead to increased morbidity with no added value in terms of elimination; the interaction is clearly antagonistic. In contrast, there is strong synergy between PEV and treated bednets that may facilitate elimination, although transient stages are likely to increase morbidity. The combination of TBV with treated bednets is synergistic, lowering both morbidity and elimination thresholds. Our results suggest that vaccines will not provide a straightforward solution to malaria control, and that future programs need to consider the synergistic and antagonistic interactions between vaccines and treated bednets.
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Wotodjo AN, Diagne N, Gaudart J, Richard V, Raoult D, Sokhna C. Malaria risk factors in Dielmo, a Senegalese malaria-endemic village, between October and November of 2013: a case-control study. Am J Trop Med Hyg 2015; 92:565-8. [PMID: 25582690 DOI: 10.4269/ajtmh.14-0485] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022] Open
Abstract
The incidence of malaria has decreased recently in parts of Africa, coinciding with the widespread use of long-lasting insecticide-treated nets (LLINs) and artemisinin-based combination therapy (ACT). This reduction was also observed in Dielmo, our study area, and it was associated with the use of ACT as the first-line treatment against malaria beginning in 2006 and the implementation of LLINs in 2008. However, an unexplained slight increase in malaria incidence was observed in October and November of 2013. The aim of this study was to identify individual and environmental risk factors for malaria using a case-control study approach. Thirty cases and sixty controls were investigated. The use of LLINs was protective against malaria (adjusted odds ratio [AOR] = 0.10; 95% confidence interval [95% CI] = 0.02-0.45; P = 0.003). The risk of malaria transmission was high among villagers who watched television outside the house or the bedroom during the night (AOR = 8.83; 95% CI = 1.39-56.22; P = 0.021). The use of LLINs should be reinforced by the use of individual protection measures to avoid malaria transmission outside of the home.
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Affiliation(s)
- Amélé N Wotodjo
- Unité de Recherche sur les Maladies Infectieuses et Tropicales Emergentes, IRD198, UM63, CNRS7278, INSERMU1095, Aix-Marseille Université, Campus UCAD-IRD, Dakar, Sénégal; Aix-Marseille Université, UMR912 SESSTIM (INSERM-IRD-AMU), Marseille, France; Institut Pasteur de Dakar, Unité d'Epidémiologie, Dakar, Sénégal; Institut Hospitalo Universitaire Mediterranee-Infection, Aix-Marseille Université, Unité de Recherche sur les Maladies Infectieuses et Tropicales Emergentes, IRD198, UM63, CNRS7278, INSERMU1095, Marseille, France
| | - Nafissatou Diagne
- Unité de Recherche sur les Maladies Infectieuses et Tropicales Emergentes, IRD198, UM63, CNRS7278, INSERMU1095, Aix-Marseille Université, Campus UCAD-IRD, Dakar, Sénégal; Aix-Marseille Université, UMR912 SESSTIM (INSERM-IRD-AMU), Marseille, France; Institut Pasteur de Dakar, Unité d'Epidémiologie, Dakar, Sénégal; Institut Hospitalo Universitaire Mediterranee-Infection, Aix-Marseille Université, Unité de Recherche sur les Maladies Infectieuses et Tropicales Emergentes, IRD198, UM63, CNRS7278, INSERMU1095, Marseille, France
| | - Jean Gaudart
- Unité de Recherche sur les Maladies Infectieuses et Tropicales Emergentes, IRD198, UM63, CNRS7278, INSERMU1095, Aix-Marseille Université, Campus UCAD-IRD, Dakar, Sénégal; Aix-Marseille Université, UMR912 SESSTIM (INSERM-IRD-AMU), Marseille, France; Institut Pasteur de Dakar, Unité d'Epidémiologie, Dakar, Sénégal; Institut Hospitalo Universitaire Mediterranee-Infection, Aix-Marseille Université, Unité de Recherche sur les Maladies Infectieuses et Tropicales Emergentes, IRD198, UM63, CNRS7278, INSERMU1095, Marseille, France
| | - Vincent Richard
- Unité de Recherche sur les Maladies Infectieuses et Tropicales Emergentes, IRD198, UM63, CNRS7278, INSERMU1095, Aix-Marseille Université, Campus UCAD-IRD, Dakar, Sénégal; Aix-Marseille Université, UMR912 SESSTIM (INSERM-IRD-AMU), Marseille, France; Institut Pasteur de Dakar, Unité d'Epidémiologie, Dakar, Sénégal; Institut Hospitalo Universitaire Mediterranee-Infection, Aix-Marseille Université, Unité de Recherche sur les Maladies Infectieuses et Tropicales Emergentes, IRD198, UM63, CNRS7278, INSERMU1095, Marseille, France
| | - Didier Raoult
- Unité de Recherche sur les Maladies Infectieuses et Tropicales Emergentes, IRD198, UM63, CNRS7278, INSERMU1095, Aix-Marseille Université, Campus UCAD-IRD, Dakar, Sénégal; Aix-Marseille Université, UMR912 SESSTIM (INSERM-IRD-AMU), Marseille, France; Institut Pasteur de Dakar, Unité d'Epidémiologie, Dakar, Sénégal; Institut Hospitalo Universitaire Mediterranee-Infection, Aix-Marseille Université, Unité de Recherche sur les Maladies Infectieuses et Tropicales Emergentes, IRD198, UM63, CNRS7278, INSERMU1095, Marseille, France
| | - Cheikh Sokhna
- Unité de Recherche sur les Maladies Infectieuses et Tropicales Emergentes, IRD198, UM63, CNRS7278, INSERMU1095, Aix-Marseille Université, Campus UCAD-IRD, Dakar, Sénégal; Aix-Marseille Université, UMR912 SESSTIM (INSERM-IRD-AMU), Marseille, France; Institut Pasteur de Dakar, Unité d'Epidémiologie, Dakar, Sénégal; Institut Hospitalo Universitaire Mediterranee-Infection, Aix-Marseille Université, Unité de Recherche sur les Maladies Infectieuses et Tropicales Emergentes, IRD198, UM63, CNRS7278, INSERMU1095, Marseille, France
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Affiliation(s)
- Melba F. Gomes
- Special Programme on Research and Training in Tropical Diseases (TDR), a co-sponsored Programme of UNICEF/UNDP/World Bank/WHO, based at the World Health Organization, Geneva, Switzerland
| | - Annette C. Kuesel
- Special Programme on Research and Training in Tropical Diseases (TDR), a co-sponsored Programme of UNICEF/UNDP/World Bank/WHO, based at the World Health Organization, Geneva, Switzerland
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Kaddumukasa M, Buwembo W, Sekikubo M, Naiwumbwe H, Namusoke F, Kiwuwa S, Oketch B, Noor R, Chilengi R, Mworozi E, Kironde F. Malariometric indices from Iganga, Uganda: baseline characterization in preparation of GMZ2 vaccine trial. BMC Res Notes 2014; 7:793. [PMID: 25380673 PMCID: PMC4232662 DOI: 10.1186/1756-0500-7-793] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/13/2013] [Accepted: 10/14/2014] [Indexed: 11/10/2022] Open
Abstract
BACKGROUND Malaria still remains the leading cause of childhood morbidity and mortality in Uganda. Interventions like malaria vaccines which reduce the malaria burden are needed in malaria endemic communities. There is need to establish baseline characteristics in vaccine trial study sites. This study determined the following baseline malariometric indices: spleen rates, bed net use, malaria parasitaemia and malaria episodes in an inception cohort of children aged 12 - 60 months in Iganga district, Uganda. METHODS In a longitudinal cohort study, 748 children were enrolled with 397 in an active follow up arm and 351 in a passive arm. The children in the two arms were followed for 6 months to determine the incidence of malaria episodes. RESULTS The overall baseline spleen rate was 8.2% (61/748) among the study participants. Of the households surveyed, about 36% reported using bed nets and almost 30% of the users had insecticide-treated nets. 274 (36.6%) of the study participants had a history of fever in the past 24 hrs at the time of the baseline survey. All participants had a peripheral blood smear for malaria parasites done at enrollment with 76.8% having the asexual form of malaria parasites. The malaria episodes per child per year were 1.5 and 0.79 in the active and passive follow up arms respectively. CONCLUSIONS There is a high prevalence of malaria asexual parasitaemia in children below five years. The bed net usage still remains low among this population. These baseline malariometric indices have important implication for malaria control interventions.
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Affiliation(s)
| | - William Buwembo
- Makerere University College of Health Sciences, Kampala, Uganda.
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Das LK, Padhi B, Sahu SS. Prediction of outcome of severe falciparum malaria in Koraput, Odisha, India: A hospital-based study. Trop Parasitol 2014; 4:105-10. [PMID: 25250231 PMCID: PMC4166794 DOI: 10.4103/2229-5070.138538] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/25/2014] [Accepted: 08/12/2014] [Indexed: 11/04/2022] Open
Abstract
BACKGROUND AND OBJECTIVES Infection with Plasmodium falciparum, caused 627,000 deaths in 2012 in the world. P. falciparum infection causes myriads of clinical manifestations. Exact clinical manifestation resulting in poor prognosis in hyper-endemic epidemiological settings need to be ascertained to save human lives. A hospital-based study was conducted to elucidate the different severe clinical presentations of falciparum malaria and to examine the critical clinical and laboratory parameters on the prognosis of these severe manifestations in a stable hyper-endemic falciparum area in the state of Odisha, India. MATERIALS AND METHODS Consecutive patients admitted in a tertiary care hospital with severe manifestations of malaria as per WHO criteria and confirmed by parasitological examination were included in the study. A detailed clinical and biochemical parameters were examined. Clinical data were reviewed before being double entered into a computer and analyzed. Statistical analyses were carried out using Epi Info 6.04. Continuous and normal distributed data were compared by two-tailed Student's t-test and proportions compared with χ(2) tests with Yates' correction or Fisher's exact test. RESULTS AND DISCUSSION A total of 1320 patients with clinical malaria, diagnosed at outpatients' department were admitted in the hospital during the 1 year study period of which, 292 (22.1%) were children under 14 years of age. The major clinical categories on admission were hyperpyrexia (70.7%), cerebral malaria (9.4%), malarial anemia (7.7%), algid malaria (1.5%), and malaria associated categories were respiratory infection (2.2%), hepatitis (2.0%), urinary tract infection (1.8%), enteric fever (3.3%), and sickle cell disease (1.2%). The overall case fatality rate (CFR) was 4.3 (57/1320). The CFR in children 12.3 (36/292) was significantly higher when compared to adults, that is, 2.0 (21/1028). The major causes of death were cerebral malaria (45.6%), malaria along with a respiratory infection (19.3%) and anemia (10.5%). Malarial anemia along sickle cell disease accounted for 19.3% of all malaria related deaths. Proportion of mortality due to acute renal failure was higher in adults. Biochemical parameters suggest involvement of multiple organs. The findings suggest that the area can be effectively managed by sustained and continuous preventive and curative efforts.
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Affiliation(s)
- Lalit Kumar Das
- Unit of Clinical Epidemiology and Chemotherapy, Vector Control Research Centre (Indian Council of Medical Research), Medical Complex, Indira Nagar, Puducherry, India
| | - Bishwanath Padhi
- Department of Internal Medicine, District Headquarters Hospital, Koraput, Odisha, India
| | - Sudhansu Sekar Sahu
- Unit of Clinical Epidemiology and Chemotherapy, Vector Control Research Centre (Indian Council of Medical Research), Medical Complex, Indira Nagar, Puducherry, India
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Murray CJL, Ortblad KF, Guinovart C, Lim SS, Wolock TM, Roberts DA, Dansereau EA, Graetz N, Barber RM, Brown JC, Wang H, Duber HC, Naghavi M, Dicker D, Dandona L, Salomon JA, Heuton KR, Foreman K, Phillips DE, Fleming TD, Flaxman AD, Phillips BK, Johnson EK, Coggeshall MS, Abd-Allah F, Abera SF, Abraham JP, Abubakar I, Abu-Raddad LJ, Abu-Rmeileh NM, Achoki T, Adeyemo AO, Adou AK, Adsuar JC, Agardh EE, Akena D, Al Kahbouri MJ, Alasfoor D, Albittar MI, Alcalá-Cerra G, Alegretti MA, Alemu ZA, Alfonso-Cristancho R, Alhabib S, Ali R, Alla F, Allen PJ, Alsharif U, Alvarez E, Alvis-Guzman N, Amankwaa AA, Amare AT, Amini H, Ammar W, Anderson BO, Antonio CAT, Anwari P, Arnlöv J, Arsenijevic VSA, Artaman A, Asghar RJ, Assadi R, Atkins LS, Badawi A, Balakrishnan K, Banerjee A, Basu S, Beardsley J, Bekele T, Bell ML, Bernabe E, Beyene TJ, Bhala N, Bhalla A, Bhutta ZA, Abdulhak AB, Binagwaho A, Blore JD, Basara BB, Bose D, Brainin M, Breitborde N, Castañeda-Orjuela CA, Catalá-López F, Chadha VK, Chang JC, Chiang PPC, Chuang TW, Colomar M, Cooper LT, Cooper C, Courville KJ, Cowie BC, Criqui MH, Dandona R, Dayama A, De Leo D, Degenhardt L, Del Pozo-Cruz B, Deribe K, Des Jarlais DC, Dessalegn M, Dharmaratne SD, Dilmen U, Ding EL, Driscoll TR, Durrani AM, Ellenbogen RG, Ermakov SP, Esteghamati A, Faraon EJA, Farzadfar F, Fereshtehnejad SM, Fijabi DO, Forouzanfar MH, Fra Paleo U, Gaffikin L, Gamkrelidze A, Gankpé FG, Geleijnse JM, Gessner BD, Gibney KB, Ginawi IAM, Glaser EL, Gona P, Goto A, Gouda HN, Gugnani HC, Gupta R, Gupta R, Hafezi-Nejad N, Hamadeh RR, Hammami M, Hankey GJ, Harb HL, Haro JM, Havmoeller R, Hay SI, Hedayati MT, Pi IBH, Hoek HW, Hornberger JC, Hosgood HD, Hotez PJ, Hoy DG, Huang JJ, Iburg KM, Idrisov BT, Innos K, Jacobsen KH, Jeemon P, Jensen PN, Jha V, Jiang G, Jonas JB, Juel K, Kan H, Kankindi I, Karam NE, Karch A, Karema CK, Kaul A, Kawakami N, Kazi DS, Kemp AH, Kengne AP, Keren A, Kereselidze M, Khader YS, Khalifa SEAH, Khan EA, Khang YH, Khonelidze I, Kinfu Y, Kinge JM, Knibbs L, Kokubo Y, Kosen S, Defo BK, Kulkarni VS, Kulkarni C, Kumar K, Kumar RB, Kumar GA, Kwan GF, Lai T, Balaji AL, Lam H, Lan Q, Lansingh VC, Larson HJ, Larsson A, Lee JT, Leigh J, Leinsalu M, Leung R, Li Y, Li Y, De Lima GMF, Lin HH, Lipshultz SE, Liu S, Liu Y, Lloyd BK, Lotufo PA, Machado VMP, Maclachlan JH, Magis-Rodriguez C, Majdan M, Mapoma CC, Marcenes W, Marzan MB, Masci JR, Mashal MT, Mason-Jones AJ, Mayosi BM, Mazorodze TT, Mckay AC, Meaney PA, Mehndiratta MM, Mejia-Rodriguez F, Melaku YA, Memish ZA, Mendoza W, Miller TR, Mills EJ, Mohammad KA, Mokdad AH, Mola GL, Monasta L, Montico M, Moore AR, Mori R, Moturi WN, Mukaigawara M, Murthy KS, Naheed A, Naidoo KS, Naldi L, Nangia V, Narayan KMV, Nash D, Nejjari C, Nelson RG, Neupane SP, Newton CR, Ng M, Nisar MI, Nolte S, Norheim OF, Nowaseb V, Nyakarahuka L, Oh IH, Ohkubo T, Olusanya BO, Omer SB, Opio JN, Orisakwe OE, Pandian JD, Papachristou C, Caicedo AJP, Patten SB, Paul VK, Pavlin BI, Pearce N, Pereira DM, Pervaiz A, Pesudovs K, Petzold M, Pourmalek F, Qato D, Quezada AD, Quistberg DA, Rafay A, Rahimi K, Rahimi-Movaghar V, Ur Rahman S, Raju M, Rana SM, Razavi H, Reilly RQ, Remuzzi G, Richardus JH, Ronfani L, Roy N, Sabin N, Saeedi MY, Sahraian MA, Samonte GMJ, Sawhney M, Schneider IJC, Schwebel DC, Seedat S, Sepanlou SG, Servan-Mori EE, Sheikhbahaei S, Shibuya K, Shin HH, Shiue I, Shivakoti R, Sigfusdottir ID, Silberberg DH, Silva AP, Simard EP, Singh JA, Skirbekk V, Sliwa K, Soneji S, Soshnikov SS, Sreeramareddy CT, Stathopoulou VK, Stroumpoulis K, Swaminathan S, Sykes BL, Tabb KM, Talongwa RT, Tenkorang EY, Terkawi AS, Thomson AJ, Thorne-Lyman AL, Towbin JA, Traebert J, Tran BX, Dimbuene ZT, Tsilimbaris M, Uchendu US, Ukwaja KN, Uzun SB, Vallely AJ, Vasankari TJ, Venketasubramanian N, Violante FS, Vlassov VV, Vollset SE, Waller S, Wallin MT, Wang L, Wang X, Wang Y, Weichenthal S, Weiderpass E, Weintraub RG, Westerman R, White RA, Wilkinson JD, Williams TN, Woldeyohannes SM, Wong JQ, Xu G, Yang YC, Yano Y, Yentur GK, Yip P, Yonemoto N, Yoon SJ, Younis M, Yu C, Jin KY, El Sayed Zaki M, Zhao Y, Zheng Y, Zhou M, Zhu J, Zou XN, Lopez AD, Vos T. Global, regional, and national incidence and mortality for HIV, tuberculosis, and malaria during 1990-2013: a systematic analysis for the Global Burden of Disease Study 2013. Lancet 2014; 384:1005-70. [PMID: 25059949 PMCID: PMC4202387 DOI: 10.1016/s0140-6736(14)60844-8] [Citation(s) in RCA: 668] [Impact Index Per Article: 66.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/28/2022]
Abstract
BACKGROUND The Millennium Declaration in 2000 brought special global attention to HIV, tuberculosis, and malaria through the formulation of Millennium Development Goal (MDG) 6. The Global Burden of Disease 2013 study provides a consistent and comprehensive approach to disease estimation for between 1990 and 2013, and an opportunity to assess whether accelerated progress has occured since the Millennium Declaration. METHODS To estimate incidence and mortality for HIV, we used the UNAIDS Spectrum model appropriately modified based on a systematic review of available studies of mortality with and without antiretroviral therapy (ART). For concentrated epidemics, we calibrated Spectrum models to fit vital registration data corrected for misclassification of HIV deaths. In generalised epidemics, we minimised a loss function to select epidemic curves most consistent with prevalence data and demographic data for all-cause mortality. We analysed counterfactual scenarios for HIV to assess years of life saved through prevention of mother-to-child transmission (PMTCT) and ART. For tuberculosis, we analysed vital registration and verbal autopsy data to estimate mortality using cause of death ensemble modelling. We analysed data for corrected case-notifications, expert opinions on the case-detection rate, prevalence surveys, and estimated cause-specific mortality using Bayesian meta-regression to generate consistent trends in all parameters. We analysed malaria mortality and incidence using an updated cause of death database, a systematic analysis of verbal autopsy validation studies for malaria, and recent studies (2010-13) of incidence, drug resistance, and coverage of insecticide-treated bednets. FINDINGS Globally in 2013, there were 1·8 million new HIV infections (95% uncertainty interval 1·7 million to 2·1 million), 29·2 million prevalent HIV cases (28·1 to 31·7), and 1·3 million HIV deaths (1·3 to 1·5). At the peak of the epidemic in 2005, HIV caused 1·7 million deaths (1·6 million to 1·9 million). Concentrated epidemics in Latin America and eastern Europe are substantially smaller than previously estimated. Through interventions including PMTCT and ART, 19·1 million life-years (16·6 million to 21·5 million) have been saved, 70·3% (65·4 to 76·1) in developing countries. From 2000 to 2011, the ratio of development assistance for health for HIV to years of life saved through intervention was US$4498 in developing countries. Including in HIV-positive individuals, all-form tuberculosis incidence was 7·5 million (7·4 million to 7·7 million), prevalence was 11·9 million (11·6 million to 12·2 million), and number of deaths was 1·4 million (1·3 million to 1·5 million) in 2013. In the same year and in only individuals who were HIV-negative, all-form tuberculosis incidence was 7·1 million (6·9 million to 7·3 million), prevalence was 11·2 million (10·8 million to 11·6 million), and number of deaths was 1·3 million (1·2 million to 1·4 million). Annualised rates of change (ARC) for incidence, prevalence, and death became negative after 2000. Tuberculosis in HIV-negative individuals disproportionately occurs in men and boys (versus women and girls); 64·0% of cases (63·6 to 64·3) and 64·7% of deaths (60·8 to 70·3). Globally, malaria cases and deaths grew rapidly from 1990 reaching a peak of 232 million cases (143 million to 387 million) in 2003 and 1·2 million deaths (1·1 million to 1·4 million) in 2004. Since 2004, child deaths from malaria in sub-Saharan Africa have decreased by 31·5% (15·7 to 44·1). Outside of Africa, malaria mortality has been steadily decreasing since 1990. INTERPRETATION Our estimates of the number of people living with HIV are 18·7% smaller than UNAIDS's estimates in 2012. The number of people living with malaria is larger than estimated by WHO. The number of people living with HIV, tuberculosis, or malaria have all decreased since 2000. At the global level, upward trends for malaria and HIV deaths have been reversed and declines in tuberculosis deaths have accelerated. 101 countries (74 of which are developing) still have increasing HIV incidence. Substantial progress since the Millennium Declaration is an encouraging sign of the effect of global action. FUNDING Bill & Melinda Gates Foundation.
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Affiliation(s)
| | | | | | - Stephen S Lim
- Institute for Health Metrics and Evaluation, Seattle, WA, USA
| | | | - D Allen Roberts
- Institute for Health Metrics and Evaluation, Seattle, WA, USA
| | | | - Nicholas Graetz
- Institute for Health Metrics and Evaluation, Seattle, WA, USA
| | - Ryan M Barber
- Institute for Health Metrics and Evaluation, Seattle, WA, USA
| | | | - Haidong Wang
- Institute for Health Metrics and Evaluation, Seattle, WA, USA
| | - Herbert C Duber
- Institute for Health Metrics and Evaluation, Seattle, WA, USA
| | - Mohsen Naghavi
- Institute for Health Metrics and Evaluation, Seattle, WA, USA
| | - Daniel Dicker
- Institute for Health Metrics and Evaluation, Seattle, WA, USA
| | - Lalit Dandona
- Institute for Health Metrics and Evaluation, Seattle, WA, USA; Public Health Foundation of India, New Delhi, India
| | | | - Kyle R Heuton
- Institute for Health Metrics and Evaluation, Seattle, WA, USA
| | | | | | | | | | | | | | | | | | | | - Jerry P Abraham
- University of Texas School of Medicine San Antonio, San Antonio, TX, USA
| | | | | | - Niveen Me Abu-Rmeileh
- Institute of Community and Public Health-Birzeti University, Ramallah, West Bank, Occupied Palestinian Territory
| | | | | | | | | | | | | | | | | | | | - Gabriel Alcalá-Cerra
- Grupo de Investigación en Ciencias de la Salud y Neurociencias (CISNEURO), Cartagena de Indias, Colombia
| | - Miguel Angel Alegretti
- Facultad de Medicina, Departamento de Medicina Preventiva y Social, Universidad de la República, Montevideo, Uruguay
| | | | | | | | | | - Francois Alla
- School of Public Health, University of Lorraine, Nancy, France
| | | | | | | | | | | | - Azmeraw T Amare
- Department of Epidemiology, University of Groningen, Groningen, The Netherlands; College of Medicine and Health Sciences, Bahir Dar University, Bahir Dar, Ethiopia
| | - Hassan Amini
- Kurdistan Environmental Health Research Center, Kurdistan University of Medical Sciences, Sanandaj, Kurdistan, Iran
| | | | | | | | | | | | | | | | - Rana J Asghar
- South Asian Public Health Forum, Islamabad, Pakistan
| | - Reza Assadi
- Mashhad University of Medical Sciences, Mashhad, Iran
| | - Lydia S Atkins
- Ministry of Health, Wellness, Human Services and Gender Relations, Castries, St. Lucia
| | - Alaa Badawi
- Public Health Agency of Canada, Toronto, ON, Canada
| | | | | | | | | | | | | | | | | | | | - Ashish Bhalla
- Postgraduate Institute of Medical Education and Research, Chandigarh, India
| | | | | | | | - Jed D Blore
- University of Melbourne, Melbourne, VIC, Australia
| | | | | | | | | | | | - Ferrán Catalá-López
- Division of Pharmacoepidemiology and Pharmacovigilance, Spanish Medicines and Healthcare Products Agency (AEMPS), Ministry of Health, Madrid, Spain
| | | | | | | | - Ting-Wu Chuang
- Department of Parasitology, College of Medicine, Taipei Medical University, Taipei, Taiwan; Center for International Tropical Medicine, College of Medicine, Taipei Medical University, Taipei, Taiwan
| | | | | | - Cyrus Cooper
- MRC Lifecourse Epidemiology Unit, University of Southampton, Southampton, UK
| | | | - Benjamin C Cowie
- Victorian Infectious Diseases Reference Laboratory, North Melbourne, VIC, Australia
| | | | | | - Anand Dayama
- Emory University School of Medicine, Atlanta, GA, USA
| | | | | | | | | | | | - Muluken Dessalegn
- Africa Medical and Research Foundation in Ethiopia, Addis Ababa, Ethiopia
| | | | | | - Eric L Ding
- Harvard School of Public Health, Cambridge, MA, USA
| | | | | | | | - Sergey Petrovich Ermakov
- The Institute of Social and Economic Studies of Population at the Russian Academy of Sciences, Moscow, Russia
| | - Alireza Esteghamati
- Endocrinology and Metabolism Research Center, Tehran University of Medical Sciences, Tehran, Iran
| | | | - Farshad Farzadfar
- Non-Communicable Diseases Research Center, Tehran University of Medical Sciences, Tehran, Iran
| | | | | | | | | | - Lynne Gaffikin
- Stanford University School of Medicine, Stanford, CA, USA
| | | | | | | | | | | | | | | | - Philimon Gona
- University of Massachusetts Medical School, Worcester, MA, USA
| | - Atsushi Goto
- Department of Diabetes Research, National Center for Global Health and Medicine, Tokyo, Japan
| | - Hebe N Gouda
- University of Queensland, Brisbane, QLD, Australia
| | | | | | - Rahul Gupta
- Kanawha Charleston Health Department, Charleston, WV, USA
| | - Nima Hafezi-Nejad
- Endocrinology and Metabolism Research Center, Tehran University of Medical Sciences, Tehran, Iran
| | | | - Mouhanad Hammami
- Wayne County Department of Health and Human Services, Detroit, MI, USA
| | - Graeme J Hankey
- School of Medicine and Pharmacology, University of Western Australia, Perth, WA, Australia
| | | | - Josep Maria Haro
- Parc Sanitari Sant Joan de Déu, CIBERSAM, University of Barcelona, Sant Boi de Llobregat, Barcelona, Spain
| | | | | | | | | | - Hans W Hoek
- Parnassia Psychiatric Institute, The Hague, Netherlands
| | | | | | | | - Damian G Hoy
- School of Population Health, Brisbane, QLD, Australia; Public Health Division, Secretariat of the Pacific Community, Noumea, New Caledonia
| | | | | | | | - Kaire Innos
- National Institute for Health Development, Tallinn, Estonia
| | | | | | | | - Vivekanand Jha
- Postgraduate Institute of Medical Education and Research, Chandigarh, India
| | - Guohong Jiang
- Tianjin Centers for Diseases Control and Prevention, Tianjin, China
| | - Jost B Jonas
- Department of Ophthalmology, Medical Faculty Mannheim of the University of Heidelberg, Mannheim, Germany
| | - Knud Juel
- The National Institute of Public Health, Copenhagen, Denmark
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- Helmholtz Centre for Infection Research, Braunschweig, Germany; German Center for Infection Research (DZIF), Hannover-Braunschweig site, Germany
| | | | - Anil Kaul
- Oklahoma State University, Tulsa, OK, USA
| | | | - Dhruv S Kazi
- University of California San Francisco, San Francisco, CA, USA
| | | | - Andre Pascal Kengne
- South African Medical Research Council, Cape Town, Western Cape, South Africa
| | - Andre Keren
- Cardiology, Hadassah Ein Kerem University Hospital, Jerusalem, Israel
| | - Maia Kereselidze
- National Centre for Disease Control and Public Health, Tbilisi, Georgia
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- Institute of Health Policy and Management, Seoul National University College of Medicine, Seoul, South Korea
| | - Irma Khonelidze
- National Centre for Disease Control and Public Health, Tbilisi, Georgia
| | | | | | - Luke Knibbs
- University of Queensland, Brisbane, QLD, Australia
| | - Yoshihiro Kokubo
- Department of Preventive Cardiology, Department of Preventive Medicine and Epidemiologic Informatics, National Cerebral and Cardiovascular Center, Suita, Osaka, Japan
| | - S Kosen
- Center for Community Empowerment, Health Policy & Humanities, NIHRD, Jakarta, Indonesia
| | | | | | - Chanda Kulkarni
- Rajrajeshwari Medical College & Hospital, Bangalore, Karnataka, India
| | - Kaushalendra Kumar
- International Institute for Population Sciences, Mumbai, Maharashtra, India
| | - Ravi B Kumar
- Indian Institute of Public Health, Public Health Foundation of India, Gurgaon, Haryana, India
| | - G Anil Kumar
- Public Health Foundation of India, New Delhi, India
| | | | - Taavi Lai
- Fourth View Consulting, Tallinn, Estonia
| | | | - Hilton Lam
- Institute of Health Policy and Development Studies, National Institutes of Health, Manila, Philippines
| | - Qing Lan
- National Cancer Institute, Rockville, MD, USA
| | | | - Heidi J Larson
- London School of Hygiene and Tropical Medicine, Bloomsbury, UK
| | | | | | - James Leigh
- University of Sydney, Sydney, NSW, Australia
| | - Mall Leinsalu
- National Institute for Health Development, Tallinn, Estonia
| | - Ricky Leung
- University at Albany, The State University of New York, Rensselaer, NY, USA
| | - Yichong Li
- Genentech, Inc, South San Francisco, CA, USA
| | - Yongmei Li
- Genentech, Inc, South San Francisco, CA, USA
| | | | - Hsien-Ho Lin
- Institute of Epidemiology and Preventive Medicine, Taipei, Taiwan
| | | | - Shiwei Liu
- National Center for Chronic and Non-communicable Disease Control and Prevention, Chinese Center for Disease Control and Prevention, Beijing, China
| | - Yang Liu
- Emory University, Atlanta, GA, USA
| | - Belinda K Lloyd
- Eastern Health Clinical School, VIC, Australia; Turning Point, Eastern Health, Fitzroy, VIC, Australia
| | | | | | | | | | - Marek Majdan
- Department of Public Health, Faculty of Health Sciences and Social Work, Trnava University, Trnava, Slovakia
| | | | | | | | - Joseph R Masci
- Elmhurst Hospital Center, Mount Sinai Services, Elmhurst, NY, USA
| | | | | | | | | | | | | | | | | | | | | | | | - Ted R Miller
- Pacific Institute for Research & Evaluation, Calverton MD, USA; Centre for Population Health Research, Curtin University, Perth, WA, Australia
| | | | | | - Ali H Mokdad
- Institute for Health Metrics and Evaluation, Seattle, WA, USA
| | | | - Lorenzo Monasta
- Institute for Maternal and Child Health-IRCCS "Burlo Garofolo," Trieste, Italy
| | - Marcella Montico
- Institute for Maternal and Child Health-IRCCS "Burlo Garofolo," Trieste, Italy
| | | | - Rintaro Mori
- National Center for Child Health and Development, Setagaya, Tokyo, Japan
| | | | | | | | - Aliya Naheed
- International Centre for Diarrhoeal Diseases Research, Dhaka, Bangladesh
| | - Kovin S Naidoo
- University of KwaZulu-Natal, Durban, KwaZulu-Natal, South Africa
| | - Luigi Naldi
- Azienda Ospedaliera papa Giovanni XXIII, Bergamo, Italy
| | | | | | - Denis Nash
- School of Public Health, City University of New York, New York, NY, USA
| | | | - Robert G Nelson
- National Institute of Diabetes and Digestive and Kidney Diseases, Phoenix, AZ, USA
| | - Sudan Prasad Neupane
- Norwegian Center for Addiction Research (SERAF), University of Oslo, Oslo, Norway
| | - Charles R Newton
- Kenya Medical Research Institute Wellcome Trust Programme, Kilifi, Kenya
| | - Marie Ng
- Institute for Health Metrics and Evaluation, Seattle, WA, USA
| | | | - Sandra Nolte
- Charité Universitätsmedizin Berlin, Berlin, Germany
| | | | | | | | | | | | | | | | - John Nelson Opio
- Lira District Local Government, Lira Municipal Council, Northern Uganda, Uganda
| | - Orish Ebere Orisakwe
- Toxicology Unit, Faculty of Pharmacy, University of Port Harcourt, Port Harcourt, Rivers State, Nigeria
| | | | | | | | | | | | | | - Neil Pearce
- London School of Hygiene and Tropical Medicine, Bloomsbury, UK
| | - David M Pereira
- 3B's Research Group-Biomaterials, Biodegradables and Biomimetics, University of Minho, Headquarters of the European Institute of Excellence on Tissue Engineering and Regenerative Medicine and ICVS/3B's-PT Government Associate Laboratory, Braga, Portugal
| | - Aslam Pervaiz
- Postgraduate Medical Institute, Lahore, Punjab, Pakistan
| | | | - Max Petzold
- Centre for Applied Biostatistics, Sahlgrenska Academy, University of Gothenburg, Gothenburg, Sweden
| | | | - Dima Qato
- College of Pharmacy, University of Illinois, Chicago, IL, USA
| | - Amado D Quezada
- National Institute of Public Health of Mexico, Cuernavaca, Morelos, Mexico
| | | | | | | | - Vafa Rahimi-Movaghar
- Sina Trauma and Surgery Research Center, Tehran University of Medical Sciences, Tehran, Iran
| | | | | | - Saleem M Rana
- Department of Public Health, University of the Punjab, Lahore, Punjab, Pakistan
| | - Homie Razavi
- Center for Disease Analysis, Louisville, CO, USA
| | | | - Giuseppe Remuzzi
- IRCCS Mario Negri Institute for Pharmacological Research, Centro Anna Maria Astori, Bergamo, Italy
| | | | - Luca Ronfani
- Institute for Maternal and Child Health-IRCCS "Burlo Garofolo," Trieste, Italy
| | | | | | | | | | - Genesis May J Samonte
- National HIV/AIDS & STI Surveillance and Strategic Information Unit, National Epidemiology Center, Department of Health, Manila, National Capital Region, Philippines
| | | | | | | | - Soraya Seedat
- Stellenbosch University, Cape Town, Western Cape, South Africa
| | - Sadaf G Sepanlou
- Digestive Diseases Research Institute, Tehran University of Medical Sciences, Tehran, Iran
| | | | - Sara Sheikhbahaei
- Endocrinology and Metabolism Research Center, Tehran University of Medical Sciences, Tehran, Iran
| | | | | | - Ivy Shiue
- Heriot-Watt University, Edinburgh, UK
| | - Rupak Shivakoti
- Center for Clinical Global Health Education, Johns Hopkins University, Baltimore, MD, USA
| | | | | | - Andrea P Silva
- Instituto Nacional de Epidemiología Dr Juan H Jara, Mar del Plata, Buenos Aires, Argentina
| | - Edgar P Simard
- Surveillance and Health Services Research Program American Cancer Society, Atlanta, GA, USA
| | | | | | - Karen Sliwa
- Faculty of Health Sciences, Hatter Institute for Cardiovascular Research in Africa, Cape Town, Western Cape, South Africa
| | | | - Sergey S Soshnikov
- Federal Research Institute for Health Organization and Informatics of Ministry of Health of the Russian Federation, Moscow, Russia
| | | | | | - Konstantinos Stroumpoulis
- KEELPNO (Centre for Disease Control, Greece, dispatched to "Alexandra" General Hospital of Athens), Athens, Greece
| | - Soumya Swaminathan
- National Institute for Research in Tuberculosis, Chennai, Tamil Nadu, India
| | - Bryan L Sykes
- Department of Criminology, Law and Society (and Sociology), University of California-Irvine, Chicago, IL, USA
| | | | | | | | - Abdullah Sulieman Terkawi
- Department of Anesthesiology, University of Virginia, Charlottesville, VA, USA; Department of Anesthesiology, King Fahad Medical City, Riyadh, Saudi Arabia
| | | | | | - Jeffrey A Towbin
- Cincinnati Children's Hospital Medical Center, Cincinnati, OH, USA
| | | | - Bach X Tran
- Johns Hopkins Bloomberg School of Public Health, Johns Hopkins University, Baltimore, MD, USA
| | - Zacharie Tsala Dimbuene
- Department of Population Sciences and Development, Faculty of Economics and Management, University of Kinshasa, Kinshasa, Democratic Republic of the Congo
| | | | | | - Kingsley N Ukwaja
- Department of Internal Medicine, Federal Teaching Hospital Abakaliki, Abakailiki, Ebonyi State, Nigeria
| | | | | | | | | | | | | | - Stein Emil Vollset
- Norwegian Institute of Public Health, Oslo, Norway; University of Bergen, Bergen, Norway
| | - Stephen Waller
- Uniformed Services University of Health Sciences, Bethesda, MD, USA
| | - Mitchell T Wallin
- VA Medical Center and Georgetown University Neurology Department, Washington, DC, USA
| | - Linhong Wang
- National Center for Chronic and Non-communicable Disease Control and Prevention, Chinese Center for Disease Control and Prevention, Beijing, China
| | - XiaoRong Wang
- Shandong University Affiliated Jinan Central Hospital, Jinan, China
| | - Yanping Wang
- National Office for Maternal and Child Health Surveillance, Chengdu, China
| | | | | | - Robert G Weintraub
- University of Melbourne, Melbourne, VIC, Australia; Murdoch Children's Research Institute, Royal Children's Hospital, Melbourne, VIC, Australia
| | | | - Richard A White
- Department of Infectious Disease Epidemiology, Division of Infectious Disease Control and Department of Health Statistics, Division of Epidemiology, Oslo, Norway
| | | | | | | | - John Q Wong
- Ateneo School of Medicine and Public Health, Pasig City, Metro Manila, Philippines
| | - Gelin Xu
- Nanjing University School of Medicine, Jinling Hospital, Nanjing, China
| | - Yang C Yang
- University of North Carolina at Chapel Hill, Chapel Hill, NC, USA
| | - Yuichiro Yano
- Division of Cardiovascular Medicine, Jichi Medical University School of Medicine, Shimotsuke, Tochigi, Japan
| | | | - Paul Yip
- The University of Hong Kong, Hong Kong, Hong Kong
| | - Naohiro Yonemoto
- National Center of Neurology and Psychiatry, Kodira, Tokyo, Japan
| | | | | | - Chuanhua Yu
- Department of Epidemiology and Biostatistics, School of Public Health and Global Health Institute, Wuhan University, Wuhan, China
| | - Kim Yun Jin
- TCM MEDICAL TK SDN BHD, Nusajaya, Johor Bahru, Malaysia
| | | | - Yong Zhao
- Chongqing Medical University, Chongqing, China
| | - Yingfeng Zheng
- Zhongshan Ophthalmic Center, Sun Yat-sen University, Guangzhou, China
| | - Maigeng Zhou
- National Center for Chronic and Non-communicable Disease Control and Prevention, Chinese Center for Disease Control and Prevention, Beijing, China
| | - Jun Zhu
- National Office for Maternal and Child Health Surveillance, Chengdu, China
| | - Xiao Nong Zou
- Cancer Institute/Hospital, Chinese Academy of Medical Sciences, Beijing, China
| | - Alan D Lopez
- University of Melbourne, Melbourne, VIC, Australia
| | - Theo Vos
- Institute for Health Metrics and Evaluation, Seattle, WA, USA
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Salam RA, Das JK, Lassi ZS, Bhutta ZA. Impact of community-based interventions for the prevention and control of malaria on intervention coverage and health outcomes for the prevention and control of malaria. Infect Dis Poverty 2014; 3:25. [PMID: 25114795 PMCID: PMC4128612 DOI: 10.1186/2049-9957-3-25] [Citation(s) in RCA: 24] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/05/2014] [Accepted: 07/22/2014] [Indexed: 11/21/2022] Open
Abstract
In this paper, we aim to evaluate the effectiveness of community-based interventions (CBIs) for the prevention and management of malaria. We conducted a systematic review and identified 42 studies for inclusion. Twenty-five of the included studies evaluated the impact of the community-based distribution of insecticide-treated nets (ITNs), indoor residual spraying (IRS), or impregnated bed sheets; 14 studies evaluated intermittent preventive therapy (IPT) delivered in community settings; two studies focused on community-based education for malaria prevention; and one study evaluated environmental management through drain cleaning. Our analysis suggests that, overall, the community-based delivery of interventions to prevent and control malaria resulted in a significant increase in ITNs ownership (RR: 2.16, 95% CI: 1.86, 2.52) and usage (RR: 1.77, 95% CI: 1.48, 2.11). However, usage of ITNs was limited to two-thirds of the population who owned them. Community-based strategies also led to a significant decrease in parasitemia (RR: 0.56, 95% CI: 0.42, 0.74), malaria prevalence (RR: 0.46, 95% CI: 0.29, 0.73), malaria incidence (RR: 0.70, 95% CI: 0.54, 0.90), and anemia prevalence (RR: 0.79, 95% CI: 0.64, 0.97). We found a non-significant impact on splenomegaly, birth outcomes (low birth weight, prematurity, stillbirth/miscarriage), anthropometric measures (stunting, wasting, and underweight), and mortality (all-cause and malaria-specific). The subgroup analysis suggested that community-based distribution of ITNs, impregnated bed sheets and IRS, and IPT are effective strategies. Qualitative synthesis suggests that high coverage could be achieved at a lower cost with the integration of CBIs with existing antenatal care and immunization campaigns. Community-based delivery of interventions to prevent and control malaria are effective strategies to improve coverage and access and reduce malaria burden, however, efforts should also be concerted to prevent over diagnosis and drug resistance.
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Affiliation(s)
- Rehana A Salam
- Division of Women and Child Health, The Aga Khan University, Karachi, Pakistan
| | - Jai K Das
- Division of Women and Child Health, The Aga Khan University, Karachi, Pakistan
| | - Zohra S Lassi
- Division of Women and Child Health, The Aga Khan University, Karachi, Pakistan
| | - Zulfiqar A Bhutta
- Center of Excellence in Women & Child Health, The Aga Khan University, Karachi, Pakistan ; Center for Global Child Health Hospital for Sick Children, Toronto, Canada
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Culminating anti-malaria efforts at long lasting insecticidal net? J Infect Public Health 2014; 7:457-64. [PMID: 25092624 DOI: 10.1016/j.jiph.2014.06.002] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/11/2014] [Revised: 05/08/2014] [Accepted: 06/13/2014] [Indexed: 11/24/2022] Open
Abstract
BACKGROUND Long-lasting insecticidal nets (LLINs) are a primary method in malaria control efforts. However, a decline in the biological efficacy and physical integrity over a period of comparatively lesser time than claimed, waning of naturally acquired immunity among regular users and misuse of LLINs are serious concerns. SEARCH AND SELECTION OF LITERATURE The literature for the current review was searched in PubMed, SCOPUS Database and Google using combined search strings of related key-words. Literature with sufficient data and information on the current subject was selected to reach a valid conclusion. FINDINGS The World Health Organization (WHO) has emphasized that LLINs should be considered a public good for people inhabiting malaria endemic settings. LLINs exhibited a cumulative effect on the vector density and may force anthropophilic mosquito vectors to find alternative animal hosts for blood meal. However, the physical integrity and biological activity of LLINs declines faster than the anticipated time due to different operational conditions and the spread of insecticide resistance. LLINs have been successful in reducing malaria incidences by either reducing or not allowing human exposure to the vector mosquitoes, but at the same time, LLINs debilitate the natural protective immunity against malaria parasite. Misuse of LLINs for deviant purposes is common and is a serious environmental concern, as people believe that traditional methods of prevention against malaria that have enabled them to survive through a long time are effective and sufficient. Moreover, people are often ill-informed regarding the toxic effects of LLINs. CONCLUSIONS Specific criteria for determining the serviceable life and guidelines on the safe washing and disposal of LLINs need to be developed, kept well-informed and closely monitored. Malaria case management, environment management and community awareness to reduce the misuse of LLINs are crucial. Focused research on developing effective anti-malarial drugs, vaccines and new insecticides to reduce resistance is imperative to tackle malaria in the future.
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Dabiré RK, Namountougou M, Diabaté A, Soma DD, Bado J, Toé HK, Bass C, Combary P. Distribution and frequency of kdr mutations within Anopheles gambiae s.l. populations and first report of the ace.1 G119S mutation in Anopheles arabiensis from Burkina Faso (West Africa). PLoS One 2014; 9:e101484. [PMID: 25077792 PMCID: PMC4117487 DOI: 10.1371/journal.pone.0101484] [Citation(s) in RCA: 55] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/22/2013] [Accepted: 06/09/2014] [Indexed: 12/03/2022] Open
Abstract
An entomological survey was carried out at 15 sites dispersed throughout the three eco-climatic regions of Burkina Faso (West Africa) in order to assess the current distribution and frequency of mutations that confer resistance to insecticides in An. gambiae s.l. populations in the country. Both knockdown (kdr) resistance mutation variants (L1014F and L1014S), that confer resistance to pyrethroid insecticides, were identified concomitant with the ace-1 G119S mutation confirming the presence of multiple resistance mechanisms in the An. gambiae complex in Burkina Faso. Compared to the last survey, the frequency of the L1014F kdr mutation appears to have remained largely stable and relatively high in all species. In contrast, the distribution and frequency of the L1014S mutation has increased significantly in An. gambiae s.l. across much of the country. Furthermore we report, for the first time, the identification of the ace.1 G116S mutation in An. arabiensis populations collected at 8 sites. This mutation, which confers resistance to organophosphate and carbamate insecticides, has been reported previously only in the An. gambiae S and M molecular forms. This finding is significant as organophosphates and carbamates are used in indoor residual sprays (IRS) to control malaria vectors as complementary strategies to the use of pyrethroid impregnated bednets. The occurrence of the three target-site resistance mutations in both An. gambiae molecular forms and now An. arabiensis has significant implications for the control of malaria vector populations in Burkina Faso and for resistance management strategies based on the rotation of insecticides with different modes of action.
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Affiliation(s)
- Roch K. Dabiré
- IRSS (Institut de Recherche en Sciences de la Santé), Centre Muraz, Bobo-Dioulasso, Burkina Faso
- * E-mail:
| | - Moussa Namountougou
- IRSS (Institut de Recherche en Sciences de la Santé), Centre Muraz, Bobo-Dioulasso, Burkina Faso
| | - Abdoulaye Diabaté
- IRSS (Institut de Recherche en Sciences de la Santé), Centre Muraz, Bobo-Dioulasso, Burkina Faso
| | - Dieudonné D. Soma
- IRSS (Institut de Recherche en Sciences de la Santé), Centre Muraz, Bobo-Dioulasso, Burkina Faso
| | - Joseph Bado
- IRSS (Institut de Recherche en Sciences de la Santé), Centre Muraz, Bobo-Dioulasso, Burkina Faso
| | - Hyacinthe K. Toé
- IRSS (Institut de Recherche en Sciences de la Santé), Centre Muraz, Bobo-Dioulasso, Burkina Faso
- Department of Vector Biology, Liverpool School of Tropical Medicine, Liverpool, United Kingdom
| | - Chris Bass
- Biological Chemistry and Crop Protection Rothamsted Research, Harpenden, United Kingdom
| | - Patrice Combary
- National Malaria Control Programme, Ministry of Health, Ouagadougou, Burkina Faso
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Global burden, distribution, and interventions for infectious diseases of poverty. Infect Dis Poverty 2014; 3:21. [PMID: 25110585 PMCID: PMC4126350 DOI: 10.1186/2049-9957-3-21] [Citation(s) in RCA: 177] [Impact Index Per Article: 17.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/05/2014] [Accepted: 07/18/2014] [Indexed: 12/21/2022] Open
Abstract
Infectious diseases of poverty (IDoP) disproportionately affect the poorest population in the world and contribute to a cycle of poverty as a result of decreased productivity ensuing from long-term illness, disability, and social stigma. In 2010, the global deaths from HIV/AIDS have increased to 1.5 million and malaria mortality rose to 1.17 million. Mortality from neglected tropical diseases rose to 152,000, while tuberculosis killed 1.2 million people that same year. Substantial regional variations exist in the distribution of these diseases as they are primarily concentrated in rural areas of Sub-Saharan Africa, Asia, and Latin America, with geographic overlap and high levels of co-infection. Evidence-based interventions exist to prevent and control these diseases, however, the coverage still remains low with an emerging challenge of antimicrobial resistance. Therefore, community-based delivery platforms are increasingly being advocated to ensure sustainability and combat co-infections. Because of the high morbidity and mortality burden of these diseases, especially in resource-poor settings, it is imperative to conduct a systematic review to identify strategies to prevent and control these diseases. Therefore, we attempted to evaluate the effectiveness of one of these strategies, that is community-based delivery for the prevention and treatment of IDoP. In this paper, we describe the burden, epidemiology, and potential interventions for IDoP. In subsequent papers of this series, we describe the analytical framework and the methodology used to guide the systematic reviews, and report the findings and interpretations of our analyses of the impact of community-based strategies on individual IDoPs.
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Lassi ZS, Salam RA, Das JK, Bhutta ZA. The conceptual framework and assessment methodology for the systematic reviews of community-based interventions for the prevention and control of infectious diseases of poverty. Infect Dis Poverty 2014; 3:22. [PMID: 25105014 PMCID: PMC4124965 DOI: 10.1186/2049-9957-3-22] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/05/2014] [Accepted: 07/18/2014] [Indexed: 11/18/2022] Open
Abstract
This paper describes the conceptual framework and the methodology used to guide the systematic reviews of community-based interventions (CBIs) for the prevention and control of infectious diseases of poverty (IDoP). We adapted the conceptual framework from the 3ie work on the 'Community-Based Intervention Packages for Preventing Maternal Morbidity and Mortality and Improving Neonatal Outcomes' to aid in the analyzing of the existing CBIs for IDoP. The conceptual framework revolves around objectives, inputs, processes, outputs, outcomes, and impacts showing the theoretical linkages between the delivery of the interventions targeting these diseases through various community delivery platforms and the consequent health impacts. We also describe the methodology undertaken to conduct the systematic reviews and the meta-analyses.
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Affiliation(s)
- Zohra S Lassi
- Division of Women and Child Health, The Aga Khan University, Karachi, Pakistan
| | - Rehana A Salam
- Division of Women and Child Health, The Aga Khan University, Karachi, Pakistan
| | - Jai K Das
- Division of Women and Child Health, The Aga Khan University, Karachi, Pakistan
| | - Zulfiqar A Bhutta
- Center of Excellence in Women & Child Health, The Aga Khan University, Karachi, Pakistan
- Center for Global Child Health Hospital for Sick Children, Toronto, Canada
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Woyessa A, Deressa W, Ali A, Lindtjørn B. Ownership and use of long-lasting insecticidal nets for malaria prevention in Butajira area, south-central Ethiopia: complex samples data analysis. BMC Public Health 2014; 14:99. [PMID: 24479770 PMCID: PMC3914706 DOI: 10.1186/1471-2458-14-99] [Citation(s) in RCA: 21] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/28/2012] [Accepted: 01/28/2014] [Indexed: 11/26/2022] Open
Abstract
BACKGROUND Despite the encroaching of endemic malaria to highland-fringe areas above 2000 meters above sea level in Ethiopia, there is limited information on ownership and use of mosquito nets for malaria prevention. Thus, this study was designed to assess long-lasting insecticidal nets (LLIN) possession and use for malaria prevention in highland-fringe of south-central Ethiopia. METHODS A multi-stage sampling technique was employed to obtain household data from randomly selected households using household head interview in October and November 2008. Household LLIN possession and use was assessed using adjusted Odds Ratio obtained from complex samples logistic regression analysis. RESULTS Only less than a quarter (23.1%) of 739 households interviewed owned LLINs with more differences between low (54.2%) high (3.5%) altitudes (Χ2 =253, P < 0.001). Higher LLIN ownership was observed in illiterate (adj.OR 35.1 [10.6-116.2]), male-headed (adj.OR 1.7 [1.051-2.89]), owning two or more beds (adj.OR 2.7 [1.6-4.6]), not doing draining/refilling of mosquito breeding sites (adj.OR 3.4 [2.1-5.5]) and absence of rivers or streams (adj.OR 6.4 [3.5-11.8]) of household variables. The presence of ≥2 LLINs hanging (adj.OR 21.0 [5.2-85.1]), owning two or more LLINs (adj.OR 4.8 [1.3-17.5]), not doing draining/refilling of mosquito breeding sites (adj.OR 4.2 [1.3-13.6]), low wealth status (adj.OR 3.55 [1.04-12.14]), and < 1 km distance from absence of rivers or streams (adj.OR 3.9 [1.2-12.1]) of households was associated with more likely use of LLIN. The LLIN ownership was low in the highlands, and most of the highland users bought the bed nets themselves. CONCLUSIONS This study found a low household LLIN ownership and use in the highland-fringe rural area. Therefore, improving the availability and teaching effective use of LLIN combined with removal of temporary mosquito breeding places should be prioritized in highland-fringe areas.
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Affiliation(s)
- Adugna Woyessa
- Ethiopian Public Health Institute, P.O. Box 1242, Gulelle Sub-City, Addis Ababa, Ethiopia
- School of Public Health, College of Health Sciences, Addis Ababa University, P. O. Box 9086, Addis Ababa, Ethiopia
| | - Wakgari Deressa
- School of Public Health, College of Health Sciences, Addis Ababa University, P. O. Box 9086, Addis Ababa, Ethiopia
| | - Ahmed Ali
- School of Public Health, College of Health Sciences, Addis Ababa University, P. O. Box 9086, Addis Ababa, Ethiopia
| | - Bernt Lindtjørn
- Centre for International Health, University of Bergen, Bergen, Norway
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Abstract
OBJECTIVES To evaluate the global and country-level burden of HIV/AIDS relative to 291 other causes of disease burden from 1980 to 2010 using the Global Burden of Disease Study 2010 (GBD 2010) as the vehicle for exploration. METHODS HIV/AIDS burden estimates were derived elsewhere as a part of GBD 2010, a comprehensive assessment of the magnitude of 291 diseases and injuries from 1990 to 2010 for 187 countries. In GBD 2010, disability-adjusted life years (DALYs) are used as the measurement of disease burden. DALY estimates for HIV/AIDS come from UNAIDS' 2012 prevalence and mortality estimates, GBD 2010 disability weights and mortality estimates derived from quality vital registration data. RESULTS Despite recent declines in global HIV/AIDS mortality, HIV/AIDS was still the fifth leading cause of global DALYs in 2010. The distribution of HIV/AIDS burden is not equal across demographics and regions. In 2010, HIV/AIDS was ranked as the leading DALY cause for ages 30-44 years in both sexes and for 21 countries that fall into four distinctive blocks: Eastern and Southern Africa, Central Africa, the Caribbean and Thailand. Although a majority of the DALYs caused by HIV/AIDS are in high-burden countries, 20% of the global HIV/AIDS burden in 2010 was in countries where HIV/AIDS did not make the top 10 leading causes of burden. CONCLUSION In the midst of a global economic recession, tracking the magnitude of the HIV/AIDS epidemic and its importance relative to other diseases and injuries is critical to effectively allocating limited resources and maintaining funding for effective HIV/AIDS interventions and treatments.
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Lozano JM, Guerrero YA, Alba MP, Lesmes LP, Escobar JO, Patarroyo ME. Redefining an epitope of a malaria vaccine candidate, with antibodies against the N-terminal MSA-2 antigen of Plasmodium harboring non-natural peptide bonds. Amino Acids 2013; 45:913-35. [PMID: 23836419 PMCID: PMC3776258 DOI: 10.1007/s00726-013-1541-x] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/01/2012] [Accepted: 06/20/2013] [Indexed: 11/10/2022]
Abstract
The aim of obtaining novel vaccine candidates against malaria and other transmissible diseases can be partly based on selecting non-polymorphic peptides from relevant antigens of pathogens, which have to be then precisely modified for inducing a protective immunity against the disease. Bearing in mind the high degree of the MSA-221–40 peptide primary structure’s genetic conservation among malaria species, and its crucial role in the high RBC binding ability of Plasmodium falciparum (the main agent causing malaria), structurally defined probes based on non-natural peptide-bond isosteres were thus designed. Thus, two peptide mimetics were obtained (so-called reduced amide pseudopeptides), in which naturally made amide bonds of the 30FIN32-binding motif of MSA-2 were replaced with ψ–[CH2–NH] methylene amide isostere bonds, one between the F–I and the second between I–N amino acid pairs, respectively, coded as ψ-128 ψ-130. These peptide mimetics were used to produce poly- and monoclonal antibodies in Aotus monkeys and BALB/c mice. Parent reactive mice-derived IgM isotype cell clones were induced to Ig isotype switching to IgG sub-classes by controlled in vitro immunization experiments. These mature isotype immunoglobulins revealed a novel epitope in the MSA-225–32 antigen and two polypeptides of rodent malaria species. Also, these antibodies’ functional activity against malaria was tested by in vitro assays, demonstrating high efficacy in controlling infection and evidencing neutralizing capacity for the rodent in vivo malaria infection. The neutralizing effect of antibodies induced by site-directed designed peptide mimetics on Plasmodium’s biological development make these pseudopeptides a valuable tool for future development of immunoprophylactic strategies for controlling malarial infection.
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Affiliation(s)
- José Manuel Lozano
- Biocatalysis Department, Fundación Instituto de Inmunología de Colombia (FIDIC), Universidad del Rosario, Carrera 50 No. 26-20, 020304, Bogotá DC, Colombia,
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