1
|
Gilmour B, Alene KA, Clements A. The prevalence of tuberculosis and malaria in minority indigenous populations of South- East Asia and the Western Pacific Region: a systematic review and meta-analysis. Pathog Glob Health 2022; 116:201-219. [PMID: 34904538 PMCID: PMC9132423 DOI: 10.1080/20477724.2021.2011579] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/16/2022] Open
Abstract
Infectious diseases have been shown to disproportionately affect indigenous populations. Tuberculosis (TB) and malaria continue to impose a significant burden on humanity and are among the infectious diseases targeted within the 2030 Agenda for Sustainable Development. A systematic review and meta-analyses were undertaken to evaluate the prevalence of TB and malaria infections within minority indigenous populations of the South-East Asia and Western Pacific Regions. The review was undertaken in accordance with The Preferred Reporting Items for Systematic Review and Meta-Analyses guidelines following a published protocol. A random effects meta-analysis was used to calculate the pooled prevalence of TB and malaria. A meta-regression analysis was applied to quantify associations with study covariates and a sub-group analysis undertaken where studies provided comparative data between minority indigenous and other population groups. From the 3,275 unique publications identified, 24 on TB, and 39 on malaria were included in the final analysis. The pooled prevalence of TB was 2.3% (95% CI: 1.7, 2.9) and the pooled prevalence of malaria was 19.9% (95% CI: 15.9, 24.2). There was significant (p = 0.000) heterogeneity (I2) between studies. Significant difference was not observed in TB and malaria prevalence between minority indigenous and other population groups, although the odds ratio of malaria infection in minority indigenous populations was 1.15 (95% CI 0.99, 1.34: p-value 0.06) compared to other population groups. The review identified a paucity of data on TB and malaria in minority indigenous populations despite the significant prevalence and burden of these diseases within these regions.
Collapse
Affiliation(s)
- Beth Gilmour
- Faculty of Health Sciences, Curtin University, Western Australia, Australia
| | - Kefyalew Addis Alene
- Faculty of Health Sciences, Curtin University, Western Australia, Australia
- Geospatial Health & Development, Telethon Kids Institute, Nedlands, WA, Australia
| | - Archie Clements
- Faculty of Health Sciences, Curtin University, Western Australia, Australia
- Geospatial Health & Development, Telethon Kids Institute, Nedlands, WA, Australia
| |
Collapse
|
2
|
Singh J, George M. Intolerable Burden of Malaria among Primitive Tribal Community in Odisha: Examining the Fundamental Cause. Journal of Health Management 2021. [DOI: 10.1177/09720634211050459] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
Abstract
This study seeks to examine the living conditions, working conditions, and health seeking behaviour for malaria among Kondho community after one is infected with malaria. The residential surroundings of those diagnosed with malaria positive cases were extremely conducive for mosquito breeding. For instance, the majority of households threw garbage near their house, went for open defecation, the cowshed was beside their houses, and above all the houses were mostly situated in the jungle or near thick forest. Sub-centre followed by the community health centres was the first point of contact in most cases but medical care was sought only after routine life was affected. While malaria treatment plans are changing towards administering more powerful drugs as a result of chloroquine resistance but not as much has been done in the ground to prevent malaria at the first place. Therefore, together with continuing curative care for malaria—more emphasis is needed on its prevention. Community, civil society and the government need to work in tandem to improve the living and working conditions of backward communities particularly those living in malaria endemic zone so as to be able to take effective preventive measures for malaria.
Collapse
Affiliation(s)
- Jayakant Singh
- School of Health Systems Studies, Tata Institute of Social Sciences, Mumbai, Maharashtra, India
| | - Mathew George
- School of Health Systems Studies, Tata Institute of Social Sciences, Mumbai, Maharashtra, India
| |
Collapse
|
3
|
Das MK, Prajapati BK, Tiendrebeogo RW, Ranjan K, Adu B, Srivastava A, Khera HK, Chauhan N, Tevatiya S, Kana IH, Sharma SK, Singh S, Theisen M. Malaria epidemiology in an area of stable transmission in tribal population of Jharkhand, India. Malar J 2017; 16:181. [PMID: 28464875 PMCID: PMC5414148 DOI: 10.1186/s12936-017-1833-9] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/17/2017] [Accepted: 04/23/2017] [Indexed: 11/10/2022] Open
Abstract
Background Malaria remains an important health problem in India with approximately 1 million cases in 2014. Of these, 7% occurred in the Jharkhand state mainly in the tribal population. Methods This study was conducted in Dumargarhi, a tribal village about 42 km east of Ranchi city, Jharkhand, from May 2014 to September 2016. Four point prevalence surveys were carried out during consecutive high (October–December) and low (June–August) transmission seasons. Malaria cases were recorded from April 2015 to April 2016 through fortnightly visits to the village. Adult mosquito densities were monitored fortnightly by manual catching using suction tube method. Results The study area consists of five hamlets inhabited by 945 individuals living in 164 households as recorded through a house-to-house census survey performed at enrollment. The study population consisted predominantly of the Munda (n = 425, 45%) and Oraon (n = 217, 23%) ethnic groups. Study participants were categorized as per their age 0–5, 6–10, 11–15 and >15 years. There were 99 cases of clinical malaria from April 2015 to April 2016 and all malaria cases confirmed by microscopy were attributed to Plasmodium falciparum (94 cases) and Plasmodium vivax (5 cases), respectively. During the high transmission season the mean density of P. falciparum parasitaemia per age group increased to a peak level of 23,601 parasites/μl in the 6–10 years age group and gradually declined in the adult population. Malaria attack rates, parasite prevalence and density levels in the study population showed a gradual decrease with increasing age. This finding is consistent with the phenomenon of naturally acquired immunity against malaria. Three vector species were detected: Anopheles fluviatilis, Anopheles annularis, and Anopheles culicifacies. The incoherence or complete out of phase pattern of the vector density peaks together with a high prevalence of parasite positive individuals in the study population explains the year-round malaria transmission in the study region. Conclusions The collection of clinical data from a well-characterized tribal cohort from Jharkhand, India, has provided evidence for naturally acquired immunity against malaria in this hyperendemic region. The study also suggests that enforcement of existing control programmes can reduce the malaria burden further.
Collapse
Affiliation(s)
- Manoj K Das
- Field Unit, National Institute of Malaria Research, Ranchi, Jharkhand, India
| | - Brijesh K Prajapati
- National Institute of Malaria Research, Indian Council of Medical Research, New Delhi, 110077, India
| | - Régis W Tiendrebeogo
- Department for Congenital Disorders, Statens Serum Institut, Artillerivej 5, 2300, Copenhagen, Denmark.,Centre for Medical Parasitology at Department of International Health, Immunology and Microbiology, University of Copenhagen, Copenhagen, Denmark.,Department of Infectious Diseases, Copenhagen University Hospital, Rigshospitalet, Copenhagen, Denmark
| | - Kumud Ranjan
- National Institute of Malaria Research, Indian Council of Medical Research, New Delhi, 110077, India
| | - Bright Adu
- Noguchi Memorial Institute for Medical Research, University of Ghana, Legon, Ghana
| | - Amit Srivastava
- Indian Institute of Integrative Medicine, Canal Road, Jammu, 180001, India
| | - Harvinder K Khera
- Indian Institute of Integrative Medicine, Canal Road, Jammu, 180001, India
| | - Narendra Chauhan
- Indian Institute of Integrative Medicine, Canal Road, Jammu, 180001, India
| | - Sanjay Tevatiya
- National Institute of Malaria Research, Indian Council of Medical Research, New Delhi, 110077, India
| | - Ikhlaq H Kana
- Department for Congenital Disorders, Statens Serum Institut, Artillerivej 5, 2300, Copenhagen, Denmark.,Centre for Medical Parasitology at Department of International Health, Immunology and Microbiology, University of Copenhagen, Copenhagen, Denmark.,Department of Infectious Diseases, Copenhagen University Hospital, Rigshospitalet, Copenhagen, Denmark
| | - Surya Kant Sharma
- National Institute of Malaria Research, Indian Council of Medical Research, New Delhi, 110077, India.
| | - Subhash Singh
- Indian Institute of Integrative Medicine, Canal Road, Jammu, 180001, India.
| | - Michael Theisen
- Department for Congenital Disorders, Statens Serum Institut, Artillerivej 5, 2300, Copenhagen, Denmark. .,Centre for Medical Parasitology at Department of International Health, Immunology and Microbiology, University of Copenhagen, Copenhagen, Denmark. .,Department of Infectious Diseases, Copenhagen University Hospital, Rigshospitalet, Copenhagen, Denmark.
| |
Collapse
|
4
|
Goswami P, Murty US, Mutheneni SR, Krishnan ST. Relative roles of weather variables and change in human population in malaria: comparison over different states of India. PLoS One 2014; 9:e99867. [PMID: 24971510 DOI: 10.1371/journal.pone.0099867] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/28/2013] [Accepted: 05/20/2014] [Indexed: 01/12/2023] Open
Abstract
Background Pro-active and effective control as well as quantitative assessment of impact of climate change on malaria requires identification of the major drivers of the epidemic. Malaria depends on vector abundance which, in turn, depends on a combination of weather variables. However, there remain several gaps in our understanding and assessment of malaria in a changing climate. Most of the studies have considered weekly or even monthly mean values of weather variables, while the malaria vector is sensitive to daily variations. Secondly, rarely all the relevant meteorological variables have been considered together. An important question is the relative roles of weather variables (vector abundance) and change in host (human) population, in the change in disease load. Method We consider the 28 states of India, characterized by diverse climatic zones and changing population as well as complex variability in malaria, as a natural test bed. An annual vector load for each of the 28 states is defined based on the number of vector genesis days computed using daily values of temperature, rainfall and humidity from NCEP daily Reanalysis; a prediction of potential malaria load is defined by taking into consideration changes in the human population and compared with the reported number of malaria cases. Results For most states, the number of malaria cases is very well correlated with the vector load calculated with the combined conditions of daily values of temperature, rainfall and humidity; no single weather variable has any significant association with the observed disease prevalence. Conclusion The association between vector-load and daily values of weather variables is robust and holds for different climatic regions (states of India). Thus use of all the three weather variables provides a reliable means of pro-active and efficient vector sanitation and control as well as assessment of impact of climate change on malaria.
Collapse
|
5
|
Pati SS, Panigrahi J, Mishra SK, Mohanty S, Mohapatra DN, Das BS. Severe complications and death in cases ofPlasmodium falciparummalaria with sickle-cell trait. Annals of Tropical Medicine & Parasitology 2013; 99:317-20. [PMID: 15829139 DOI: 10.1179/136485905x28036] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/28/2022]
Affiliation(s)
- S S Pati
- Department of Biochemistry, Ispat General Hospital, Rourkela--769005, Orissa, India.
| | | | | | | | | | | |
Collapse
|
6
|
Shah NK, Tyagi P, Sharma SK. The impact of artemisinin combination therapy and long-lasting insecticidal nets on forest malaria incidence in tribal villages of India, 2006-2011. PLoS One 2013; 8:e56740. [PMID: 23437229 PMCID: PMC3577711 DOI: 10.1371/journal.pone.0056740] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/01/2012] [Accepted: 01/14/2013] [Indexed: 11/19/2022] Open
Abstract
INTRODUCTION New tools for malaria control, artemisinin combination therapy (ACT) and long-lasting insecticidal nets (LLINs) were recently introduced across India. We estimated the impact of universal coverage of ACT and ACT plus LLINs in a setting of hyperendemic, forest malaria transmission. METHODS We reviewed data collected through active and passive case detection in a vaccine trial cohort of 2,204 tribal people residing in Sundargarh district, Odisha between 2006 and 2011. We compared measures of transmission at the village and individual level in 2006-2009 versus 2010-2011 after ACT (in all villages) and LLINs (in three villages) were implemented. RESULTS During 2006-2009 malaria incidence per village ranged from 156-512 per 1000 persons per year and slide prevalence ranged from 28-53%. Routine indoor residual spray did not prevent seasonal peaks of malaria. Post-intervention impact in 2010-2011 was dramatic with ranges of 14-71 per 1000 persons per year and 6-16% respectively. When adjusted for village, ACT alone decreased the incidence of malaria by 83% (IRR 0.17, 95%CI: 0.10, 0.27) and areas using ACT and LLINs decreased the incidence of malaria by 86% (IRR 0.14, 95%CI: 0.05, 0.38). After intervention, the age of malaria cases, their parasite density, and proportion with fever at the time of screening increased. CONCLUSIONS ACT, and LLINs along with ACT, effectively reduced malaria incidence in a closely monitored population living in a forest ecotype. It is unclear whether LLINs were impactful when prompt and quality antimalarial treatment was available. In spite of universal coverage, substantial malaria burden remained.
Collapse
Affiliation(s)
- Naman K. Shah
- National Institute of Malaria Research, New Delhi, India
| | - Prajesh Tyagi
- National Institute of Malaria Research, New Delhi, India
| | - Surya K. Sharma
- National Institute of Malaria Research, New Delhi, India
- * E-mail:
| |
Collapse
|
7
|
Abstract
To deal with the variability of malaria, control programmes need to stratify their malaria problem into a number of smaller units. Such stratification may be based on the epidemiology of malaria or on its determinants such as ecology. An ecotype classification was developed by the World Health Organization (WHO) around 1990, and it is time to assess its usefulness for current malaria control as well as for malaria modelling on the basis of published research. Journal and grey literature was searched for articles on malaria or Anopheles combined with ecology or stratification. It was found that all malaria in the world today could be assigned to one or more of the following ecotypes: savanna, plains and valleys; forest and forest fringe; foothill; mountain fringe and northern and southern fringes; desert fringe; coastal and urban. However, some areas are in transitional or mixed zones; furthermore, the implications of any ecotype depend on the biogeographical region, sometimes subregion, and finally, the knowledge on physiography needs to be supplemented by local information on natural, anthropic and health system processes including malaria control. Ecotyping can therefore not be seen as a shortcut to determine control interventions, but rather as a framework to supplement available epidemiological and entomological data so as to assess malaria situations at the local level, think through the particular risks and opportunities and reinforce intersectoral action. With these caveats, it does however emerge that several ecotypic distinctions are well defined and have relatively constant implications for control within certain biogeographic regions. Forest environments in the Indo-malay and the Neotropics are, with a few exceptions, associated with much higher malaria risk than in adjacent areas; the vectors are difficult to control, and the anthropic factors also often converge to impose constraints. Urban malaria in Africa is associated with lower risk than savanna malaria; larval control may be considered though its role is not so far well established. In contrast, urban malaria in the Indian subcontinent is associated with higher risks than most adjacent rural areas, and larval control has a definite, though not exclusive, role. Simulation modelling of cost-effectiveness of malaria control strategies in different scenarios should prioritize ecotypes where malaria control encounters serious technical problems. Further field research on malaria and ecology should be interdisciplinary, especially with geography, and pay more attention to juxtapositions and to anthropic elements, especially migration.
Collapse
Affiliation(s)
- Allan Schapira
- Swiss Tropical and Public Health Institute, Basel, Switzerland
| | | |
Collapse
|
8
|
Dhingra N, Jha P, Sharma VP, Cohen AA, Jotkar RM, Rodriguez PS, Bassani DG, Suraweera W, Laxminaryan R, Peto R. Adult and child malaria mortality in India: a nationally representative mortality survey. Lancet 2010; 376:1768-74. [PMID: 20970179 PMCID: PMC3021416 DOI: 10.1016/s0140-6736(10)60831-8] [Citation(s) in RCA: 178] [Impact Index Per Article: 12.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
BACKGROUND National malaria death rates are difficult to assess because reliably diagnosed malaria is likely to be cured, and deaths in the community from undiagnosed malaria could be misattributed in retrospective enquiries to other febrile causes of death, or vice-versa. We aimed to estimate plausible ranges of malaria mortality in India, the most populous country where the disease remains common. METHODS Full-time non-medical field workers interviewed families or other respondents about each of 122,000 deaths during 2001-03 in 6671 randomly selected areas of India, obtaining a half-page narrative plus answers to specific questions about the severity and course of any fevers. Each field report was sent to two of 130 trained physicians, who independently coded underlying causes, with discrepancies resolved either via anonymous reconciliation or adjudication. FINDINGS Of all coded deaths at ages 1 month to 70 years, 2681 (3·6%) of 75,342 were attributed to malaria. Of these, 2419 (90%) were in rural areas and 2311 (86%) were not in any health-care facility. Death rates attributed to malaria correlated geographically with local malaria transmission ratesderived independently from the Indian malaria control programme. The adjudicated results show 205,000 malaria deaths per year in India before age 70 years (55,000 in early childhood, 30,000 at ages 5-14 years, 120,000 at ages 15-69 years); 1·8% cumulative probability of death from malaria before age 70 years. Plausible lower and upper bounds (on the basis of only the initial coding) were 125,000-277,000. Malaria accounted for a substantial minority of about 1·3 million unattended rural fever deaths attributed to infectious diseases in people younger than 70 years. INTERPRETATION Despite uncertainty as to which unattended febrile deaths are from malaria, even the lower bound greatly exceeds the WHO estimate of only 15,000 malaria deaths per year in India (5000 early childhood, 10 000 thereafter). This low estimate should be reconsidered, as should the low WHO estimate of adult malaria deaths worldwide. FUNDING US National Institutes of Health, Canadian Institute of Health Research, Li Ka Shing Knowledge Institute.
Collapse
Affiliation(s)
- Neeraj Dhingra
- National AIDS Control Organization, New Delhi 100110, India
- Centre for Global Health Research (CGHR), Li Ka Shing Knowledge Institute, St. Michael's Hospital and Dalla Lana School of Public Health, University of Toronto, Ontario M5B 2C5, Canada
| | - Prabhat Jha
- Centre for Global Health Research (CGHR), Li Ka Shing Knowledge Institute, St. Michael's Hospital and Dalla Lana School of Public Health, University of Toronto, Ontario M5B 2C5, Canada
- Correspondence: or
| | - Vinod P Sharma
- Centre for Rural Development and Technology, Indian Institute of Technology, New Delhi 110016
| | - Alan A Cohen
- Centre for Global Health Research (CGHR), Li Ka Shing Knowledge Institute, St. Michael's Hospital and Dalla Lana School of Public Health, University of Toronto, Ontario M5B 2C5, Canada
| | - Raju M Jotkar
- Centre for Global Health Research (CGHR), Li Ka Shing Knowledge Institute, St. Michael's Hospital and Dalla Lana School of Public Health, University of Toronto, Ontario M5B 2C5, Canada
- St. John's Research Institute, Bangalore, Karnataka 560034, India
| | - Peter S Rodriguez
- Centre for Global Health Research (CGHR), Li Ka Shing Knowledge Institute, St. Michael's Hospital and Dalla Lana School of Public Health, University of Toronto, Ontario M5B 2C5, Canada
| | - Diego G Bassani
- Centre for Global Health Research (CGHR), Li Ka Shing Knowledge Institute, St. Michael's Hospital and Dalla Lana School of Public Health, University of Toronto, Ontario M5B 2C5, Canada
| | - Wilson Suraweera
- Centre for Global Health Research (CGHR), Li Ka Shing Knowledge Institute, St. Michael's Hospital and Dalla Lana School of Public Health, University of Toronto, Ontario M5B 2C5, Canada
| | | | - Richard Peto
- Clinical Trial Service Unit & Epidemiological Studies Unit (CTSU), University of Oxford, OX3 7LF, UK
| |
Collapse
|
9
|
Sharma SK, Tyagi PK, Upadhyay AK, Haque MA, Mohanty SS, Raghavendra K, Dash AP. Efficacy of permethrin treated long-lasting insecticidal nets on malaria transmission and observations on the perceived side effects, collateral benefits and human safety in a hyperendemic tribal area of Orissa, India. Acta Trop 2009; 112:181-7. [PMID: 19647715 DOI: 10.1016/j.actatropica.2009.07.022] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/16/2009] [Revised: 07/21/2009] [Accepted: 07/23/2009] [Indexed: 11/30/2022]
Abstract
Studies were conducted on the efficacy of Olyset nets-a long-lasting insecticidal net (LLIN) factory treated with 2% (w/w) permethrin on malaria transmission in an area under the influence of pyrethroid susceptible vector species Anopheles culicifacies and A. fluviatilis in Sundargarh District, Orissa, India. The study area comprised 22 villages that were randomized into three clusters and designated as Olyset net, untreated net, and no net area. Malaria incidence in the study population was measured through longitudinal active surveillance at fortnightly intervals. There was a reduction of 65-70% in malaria incidence in Olyset net area as compared to the control areas. The attack rate of Plasmodium falciparum or number of episodes per person per year in different age groups also showed significant reduction in Olyset net area as compared to untreated net and no net areas. Cross-sectional point prevalence surveys showed 45.7% reduction of malaria prevalence in Olyset net users, whereas there was an increase of 33.3% and 51% in untreated net and no net villages respectively. The compliance rate of Olyset net usage in the study population was 80-98% during different months, whereas it was between 70% and 90% for untreated nets. There were minimal complains of skin irritation (4%), itching (8%) and eye irritation (1.2%). However, these effects were only transitory in nature lasting for few hours of the first usage. Olyset nets also provided collateral benefits in terms of relief not only from mosquitoes and malaria but also from other household pests such as head lice, bed bugs, cockroaches, ants and houseflies. The Olyset nets were found to be safe to humans as no adverse event was recorded in the net users that can be attributed to the use of net. The study showed that Olyset nets are effective personal protection tool that can be used in a community based intervention programme.
Collapse
Affiliation(s)
- Surya K Sharma
- National Institute of Malaria Research, Field Station, Rourkela 769002, Orissa, India.
| | | | | | | | | | | | | |
Collapse
|
10
|
Sharma SK, Upadhyay AK, Haque MA, Tyagi PK, Mohanty SS, Raghavendra K, Dash AP. Field evaluation of Olyset nets: a long-lasting insecticidal net against malaria vectors Anopheles culicifacies and Anopheles fluviatilis in a hyperendemic tribal area of Orissa, India. J Med Entomol 2009; 46:342-350. [PMID: 19351086 DOI: 10.1603/033.046.0220] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/27/2023]
Abstract
A village-scale trial was conducted on the efficacy of Olyset nets: a long-lasting insecticidal net (LLIN) factory treated with 2% wt:wt permethrin against malaria vectors Anopheles culicifacies Giles and Anopheles fluviatilis James, in Sundargarh District, Orissa, India. The study area comprised 22 villages that were randomized into three clusters and designated as Olyset net, untreated net, and no net clusters. Baseline studies showed that both vector species were 100% susceptible to permethrin. Results of wash resistance and bioefficacy of Olyset nets showed 100% mortality in An. culicifacies up to 11 washings, whereas 100% mortality was observed in An. fluviatilis even after 20 washings. The median knock-down time for these species ranged between 4.55-6.00 and 4.45-5.45 min, respectively, during 1 yr of intervention. In the Olyset net study area, there was a significant reduction of 80.6, 94.1, and 76.7% in the entry rate of An. culicifacies, An. fluviatilis, and other anopheline species, respectively, with an overall reduction of 63.5% in total mosquitoes. Floor sheet collections in houses with Olyset nets indicated 39% immediate mortality in total mosquitoes. The overall feeding success rate of mosquitoes in the trial village was only 18.0% in comparison to 44.2 and 79.1% in villages with untreated nets and no nets, respectively. A significant reduction was also recorded in parity rate and human blood index of vector species in the Olyset net area. This study showed that Olyset nets are an effective personal protection tool that can be used in a community-based intervention program.
Collapse
Affiliation(s)
- S K Sharma
- National Institute of Malaria Research, Field Station, Sector-5, Rourkela 769 002, Orissa, India.
| | | | | | | | | | | | | |
Collapse
|
11
|
Sharma SK, Upadhyay AK, Haque MA, Padhan K, Tyagi PK, Ansari MA, Dash AP. Wash resistance and bioefficacy of Olyset net--a long-lasting insecticide-treated mosquito net against malaria vectors and nontarget household pests. J Med Entomol 2006; 43:884-8. [PMID: 17017224 DOI: 10.1603/0022-2585(2006)43[884:wraboo]2.0.co;2] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/12/2023]
Abstract
During recent years, long-lasting insecticide-treated nets (LLINs) have been developed to overcome the problems of low retreatment rates, washing, and erratic dose of the insecticide resulting in the dilution of efficacy of the conventional insecticide-treated mosquito nets. These nets are treated at factory level with insecticide either incorporated into or coated around fibers. Olyset net, a polyethylene net with 2% permethrin incorporated within fibers, is one type of LLIN. Therefore, these nets were evaluated for their wash resistance and bioefficacy against malaria vectors Anopheles culicifacies Giles and Anopheles fluviatilis James (Diptera: Culicidae) and other nontarget species. Cone bioassay tests produced 100% mortality in these two vector species with 3-min exposure. Results of the bioassays on washed nets showed 100% mortality in An. fluviatilis even after 20 washings, whereas in An. culicifacies 100% mortality up to 11 washings and 80% mortality up to 20 washings were observed. Cone bioassay tests also were performed on nontarget mosquito species Culex quinquefasciatus Say; house fly, Musca domestica L.; American cockroach, Periplaneta americana (L.); head louse, Pediculus humanus capitis De Geer; and bed bug, Cimex lectularius L. with 30-min exposure. Except for bed bugs, 100% mortality was observed in these nontarget species after 24-h recovery period. In bed bugs, only 25% mortality was observed. The density of An. culicifacies and An. fluviatilis was significantly reduced in houses with Olyset nets compared with those with untreated nets or no nets. Thus, it may be concluded that Olyset nets are highly effective against malaria vectors and moderately against other nontarget household insects.
Collapse
Affiliation(s)
- S K Sharma
- National Institute of Malaria Research, Field Station, Sector-5, Rourkela 769 002, Orissa, India
| | | | | | | | | | | | | |
Collapse
|
12
|
Sharma SK, Tyagi PK, Padhan K, Upadhyay AK, Haque MA, Nanda N, Joshi H, Biswas S, Adak T, Das BS, Chauhan VS, Chitnis CE, Subbarao SK. Epidemiology of malaria transmission in forest and plain ecotype villages in Sundargarh District, Orissa, India. Trans R Soc Trop Med Hyg 2006; 100:917-25. [PMID: 16697022 DOI: 10.1016/j.trstmh.2006.01.007] [Citation(s) in RCA: 65] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/27/2005] [Revised: 01/05/2006] [Accepted: 01/05/2006] [Indexed: 11/19/2022] Open
Abstract
A study of the epidemiology of malaria transmission was undertaken in 13 tribal villages located in forest and plain areas of Sundargarh District of Orissa state, India, from January 2001 to December 2003. In forest areas, intense transmission of malaria is attributed to the highly anthropophagic vector Anopheles fluviatilis sibling species S and is complemented by A. culicifacies sibling species C. In plain areas, A. culicifacies sibling species C is responsible for malaria transmission. The entomological inoculation rate in the forest and plain areas was 0.311 and 0.014 infective bites/person/night, respectively, during 2003. Malaria transmission is perennial both in forest and plain areas but is markedly low in the plain area compared with the forest area. Plasmodium falciparum accounted for 85.0% of the total malaria cases during the study period. In forest and plain areas, the number of P. falciparum cases per 1000 population per year was 284.1 and 31.2, respectively, whereas the parasite rate was 14.0% and 1.7%, respectively. In forest areas, clinical malaria occurs more frequently in children aged 0-5 years and declines gradually with increasing age. The study showed that villages in forest and plain areas separated by short geographical distances have distinct epidemiology of malaria transmission.
Collapse
Affiliation(s)
- Surya K Sharma
- National Institute of Malaria Research (formerly Malaria Research Centre), Field Station, Sector-5, Rourkela 769002, District Sundargarh, Orissa, India.
| | | | | | | | | | | | | | | | | | | | | | | | | |
Collapse
|
13
|
Abstract
Global environmental change is expected to affect profoundly the transmission of the parasites that cause human malaria. Amongst the anthropogenic drivers of change, deforestation is arguably the most conspicuous, and its rate is projected to increase in the coming decades. The canonical epidemiological understanding is that deforestation increases malaria risk in Africa and the Americas and diminishes it in South-east Asia. Partial support for this position is provided here, through a systematic review of the published literature on deforestation, malaria and the relevant vector bionomics. By using recently updated boundaries for the spatial limits of malaria and remotely-sensed estimates of tree cover, it has been possible to determine the population at risk of malaria in closed forest, at least for those malaria-endemic countries that lie within the main blocks of tropical forest. Closed forests within areas of malaria risk cover approximately 1.5 million km2 in the Amazon region, 1.4 million km2 in Central Africa, 1.2 million km2 in the Western Pacific, and 0.7 million km2 in South-east Asia. The corresponding human populations at risk of malaria within these forests total 11.7 million, 18.7 million, 35.1 million and 70.1 million, respectively. By coupling these numbers with the country-specific rates of deforestation, it has been possible to rank malaria-endemic countries according to their potential for change in the population at risk of malaria, as the result of deforestation. The on-going research aimed at evaluating these relationships more quantitatively, through the Malaria Atlas Project (MAP), is highlighted.
Collapse
Affiliation(s)
- C A Guerra
- TALA Research Group, Tinbergen Building, Department of Zoology, University of Oxford, South Parks Road, Oxford OX1 3PS, UK.
| | | | | |
Collapse
|
14
|
Sharma SK, Upadhyay AK, Haque MA, Padhan K, Tyagi PK, Batra CP, Adak T, Dash AP, Subbarao SK. Effectiveness of mosquito nets treated with a tablet formulation of deltamethrin for malaria control in a hyperendemic tribal area of Sundargarh District, Orissa, India. J Am Mosq Control Assoc 2006; 22:111-8. [PMID: 16646332 DOI: 10.2987/8756-971x(2006)22[111:eomntw]2.0.co;2] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/08/2023]
Abstract
A village-scale trial on the efficacy of mosquito nets treated with a tablet formulation of deltamethrin (K-OTAB) against malaria in comparison to untreated nets or no net was conducted in Sundargarh District of Orissa, India, which is characterized by perennial transmission with Plasmodium falciparum accounting for more than 80% of malaria cases. Three villages with similar topographical and epidemiological situations were selected and randomly assigned to 3 arms of the study: treated net, untreated net, and no net. Distribution of nets, based on a sleeping pattern survey, was carried out to cover 100% of the population in treated-net and untreated-net villages. Longitudinal and cross-sectional surveys were conducted to measure malaria incidence, prevalence, and splenomegaly. Malaria incidence was reduced by 64.3% in the village with treated nets, 45.2% in the village with plain nets, and 21.4% in the control village without nets. Comparison of malaria incidence data after 1 year of intervention showed significant difference between villages with treated net vs. untreated net (P < 0.05) and treated net vs. no net (P < 0.005). The incidence of clinical attack rate due to P. falciparum was significantly lower in the population using treated nets than in those using untreated nets and no nets. However, no age-specific protective efficacy of treated nets or untreated nets was observed. A significant reduction occurred in spleen rate and parasite rate in children aged 2-9 years using treated nets or untreated nets. An overall significant reduction was found in parasite rate in the total population using treated and untreated nets as compared to nonusers.
Collapse
Affiliation(s)
- Surya K Sharma
- Malaria Research Centre (ICMR), Field Station, Sector-5, Rourkela-769002, Orissa, India
| | | | | | | | | | | | | | | | | |
Collapse
|
15
|
Sharma SK, Upadhyay AK, Haque MA, Padhan K, Tyagi PK, Batra CP, Adak T, Dash AP, Subbarao SK. Village-scale evaluation of mosquito nets treated with a tablet formulation of deltamethrin against malaria vectors. Med Vet Entomol 2005; 19:286-92. [PMID: 16134977 DOI: 10.1111/j.1365-2915.2005.00571.x] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/04/2023]
Abstract
A field trial was carried out in the Sundargarh district of Orissa, India on the efficacy of mosquito nets treated with a tablet formulation of deltamethrin (K-O TAB) against malaria vectors. Treated nets were used in one village, and in the two control villages, one used untreated nets and the other used indoor spraying with DDT, without nets. In this area the primary malaria vectors are Anopheles culicifacies Giles sensu lato (Diptera: Culicidae) and An. fluviatilis James s.l., which are both endophagic and endophilic, and fully susceptible to deltamethrin. Treatment of a 10-m(2) mosquito net with one of the tablets gave a deltamethrin deposit of 25 mg/m(2). Bioassays repeated on domestically used nets over 7 months showed persistence of almost 100% mortality of An. fluviatilis, whereas An. culicifacies showed a decline from 100% to 71% mortality over this period, after which the nets were re-treated and bioassays were not continued. The sum of collections of mosquitoes resting in village houses and those in exit traps and dead on floor sheets showed a reduction in the numbers of the two vector species due to the treated nets, compared with untreated or no nets, but no reduction in other anophelines or Culex species. Large proportions of the collections of the vector and non-vector anophelines were dead on the floor sheets, but among Culex, mortality was delayed. Treated and untreated nets reduced the proportion of anophelines that had blood-fed; the treated nets did so more effectively than the untreated in the case of An. culicifacies and of Culex mosquitoes. In rooms with treated nets a larger proportion of the total collections [dead + live] were in the exit traps, which can be attributed to the excito-repellent effect of deltamethrin. It is easier to pack and handle tablets of insecticide than liquid concentrate and the use of one tablet per net may be preferable to making up a large volume of diluted insecticide and dipping many nets at a time.
Collapse
Affiliation(s)
- S K Sharma
- Malaria Research Centre (ICMR), Field station, Sector-5, Rourkela 769-002, Orissa, India.
| | | | | | | | | | | | | | | | | |
Collapse
|