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Zeleke MT, Gelaye KA, Hirpa AA, Teshome MB, Guma GT, Abate BT, Yenesew MA. Diagnostic performance of PfHRP2/pLDH malaria rapid diagnostic tests in elimination setting, northwest Ethiopia. PLOS Glob Public Health 2023; 3:e0001879. [PMID: 37428720 DOI: 10.1371/journal.pgph.0001879] [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] [Subscribe] [Scholar Register] [Received: 12/02/2022] [Accepted: 06/07/2023] [Indexed: 07/12/2023]
Abstract
Accurate diagnosis of malaria is vital for the effectiveness of parasite clearance interventions in elimination settings. Thus, evaluating the diagnostic performance of rapid diagnostic tests (RDTs) used in malaria parasite clearance interventions in elimination settings is essential. Therefore, this study aimed to evaluate the diagnostic performance of rapid diagnostic tests recently used in detecting malaria parasites in northwest Ethiopia. A facility-based cross-sectional study was conducted from November 2020 to February 2021 comparing PfHRP2/pLDH CareStart malaria RDTs with light microscopy and polymerase chain reaction (PCR). Blood samples were collected from 310 febrile patients who attended the outpatient department and examined using CareStart RDTs, light microscopy, and PCR. Statistical analyses were performed using STATA/SE version 17.0. The sensitivity of PfHRP2/pLDH CareStart malaria RDTs, regardless of species, was 81.0% [95% CI, 75.3, 86.7] and 75.8% [95% CI, 69.6, 82.0] compared to light microscopy and PCR, while the specificity was 96.8% [95% CI, 93.7, 99.9] and 93.2% [95% CI, 88.6, 97.8], respectively. The false-negative rate of CareStart malaria RDTs in comparison with light microscopy and PCR was 19.0% and 24.2%, respectively. The level of agreement beyond chance between tests was substantial, RDT versus microscopy was 75.0% and RDT versus PCR was 65.1%. The diagnostic performance of PfHRP2/pLDH CareStart RDTs in detecting malaria parasites among febrile patients in the study area was below the recommended WHO standard. The limited diagnostic performance of RDTs in the malaria elimination area undoubtedly affects the impact of malaria parasite clearance interventions. Therefore, parasite clearance intervention like targeted mass drug administration with antimalarial drugs is recommended to back up the limited diagnostic performance of the RDT or replace the existing malaria RDTs with more sensitive, field-deployable, and affordable diagnostic tests.
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Affiliation(s)
| | | | - Adugna Abera Hirpa
- Ethiopian Public Health Institute, Malaria, and Neglected Tropical Diseases Research Team, Addis Ababa, Ethiopia
| | - Mahlet Belachew Teshome
- Ethiopian Public Health Institute, Malaria, and Neglected Tropical Diseases Research Team, Addis Ababa, Ethiopia
| | - Geremew Tasew Guma
- Ethiopian Public Health Institute, Malaria, and Neglected Tropical Diseases Research Team, Addis Ababa, Ethiopia
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Duguma T, Tekalign E, Abera M, Borquaye LS. Trends of Malaria Prevalence in Selected Districts of Kaffa Zone, Southwest Ethiopia. J Trop Med 2022; 2022:1-8. [PMID: 36274749 PMCID: PMC9586818 DOI: 10.1155/2022/3556140] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/03/2022] [Revised: 09/28/2022] [Accepted: 10/03/2022] [Indexed: 11/18/2022] Open
Abstract
Background Malaria remains one of the world's major public health issues, particularly in low- and middle-income countries. In Ethiopia, cases have declined over the last decade, and attempts to eradicate the illness are underway. The purpose of this study was to determine trends in malaria prevalence in selected areas of the Kaffa zone during the last five years (Decha and Gimbo districts). Methods All malaria cases registered from 2017 to 2021 were reviewed to assess the trends of malaria prevalence. A checklist was used to collect the secondary data from registers and entered it into an Excel spreadsheet, which was then exported to the Statistical Package for the Social Sciences (SPSS) version 25.0 for analysis. The malaria incidence rate was calculated with the total number of person-years as the denominator and the number of new cases as the numerator. Seasons, years, gender, age, and malaria parasite species were all used to show trends in malaria transmission in the areas. Tables and figures were used to present the data. Results Out of 20,045 individuals screened for malaria, 13.6% (2,732/20,045) of them were recorded to have Plasmodium species tested using microscopy and rapid diagnostic test (RDT). Plasmodium falciparum, Plasmodium vivax, and mixed infections (Plasmodium falciparum + Plasmodium vivax) accounted for 1200 (5.9%), 1114 (5.56%), and 418 (2.09%) of the confirmed malaria cases, respectively. Overall, malaria incidence decreased with an interannual variation, from 4.08 cases per 1000 person-years in 2017 to 3.62 cases per 1000 person-years in 2018, then increased to 4.94 cases per 1000 person-years in 2021. Conclusion The malaria trend over the last five years has revealed a nonconsistent pattern of cases in different years. The number of malaria cases has shown an increase over the period of 2017 to 2021. Interannual and intra-annual variations have been observed in the transmission of the disease.
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Zeleke MT, Gelaye KA, Yenesew MA. Spatiotemporal variation of malaria incidence in parasite clearance interventions and non-intervention areas in the Amhara Regional State, Ethiopia. PLoS One 2022; 17:e0274500. [PMID: 36121809 PMCID: PMC9484658 DOI: 10.1371/journal.pone.0274500] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [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: 02/26/2022] [Accepted: 08/29/2022] [Indexed: 11/19/2022] Open
Abstract
Background In Ethiopia, malaria remains a major public health problem. To eliminate malaria, parasite clearance interventions were implemented in six kebeles (the lowest administrative unit) in the Amhara region. Understanding the spatiotemporal distribution of malaria is essential for targeting appropriate parasite clearance interventions to achieve the elimination goal. However, little is known about the spatiotemporal distribution of malaria incidence in the intervention and non-intervention areas. This study aimed to investigate the spatiotemporal distribution of community-based malaria in the intervention and non-intervention kebeles between 2013 and 2018 in the Amhara Regional State, Ethiopia. Methods Malaria data from 212 kebeles in eight districts were downloaded from the District Health Information System2 (DHIS2) database. We used Autoregressive integrated moving average (ARIMA) model to investigate seasonal variations; Anselin Local Moran’s I statistical analysis to detect hotspot and cold spot clusters of malaria cases; and a discrete Poisson model using Kulldorff scan statistics to identify statistically significant clusters of malaria cases. Results The result showed that the reduction in the trend of malaria incidence was higher in the intervention areas compared to the non-intervention areas during the study period with a slope of -0.044 (-0.064, -0.023) and -0.038 (-0.051, -0.024), respectively. However, the difference was not statistically significant. The Global Moran’s I statistics detected the presence of malaria clusters (z-score = 12.05; p<0.001); the Anselin Local Moran’s I statistics identified hotspot malaria clusters at 21 locations in Gendawuha and Metema districts. A statistically significant spatial, temporal, and space-time cluster of malaria cases were detected. Most likely type of spatial clusters of malaria cases (LLR = 195501.5; p <0.001) were detected in all kebeles of Gendawuha and Metema districts. The temporal scan statistic identified three peak periods between September 2013 and November 2015 (LLR = 8727.5; p<0.001). Statistically significant most-likely type of space-time clusters of malaria cases (LLR = 97494.3; p<0.001) were detected at 22 locations from June 2014 to November 2016 in Metema district. Conclusion There was a significant decline in malaria incidence in the intervention areas. There were statistically significant spatiotemporal variations of malaria in the study areas. Applying appropriate parasite clearance interventions is highly recommended for the better achievement of the elimination goal. A more rigorous evaluation of the impact of parasite clearance interventions is recommended.
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Affiliation(s)
- Melkamu Tiruneh Zeleke
- School of Public Health, College of Medicine and Health Sciences, Bahir Dar University, Bahir Dar, Ethiopia
- * E-mail:
| | | | - Muluken Azage Yenesew
- School of Public Health, College of Medicine and Health Sciences, Bahir Dar University, Bahir Dar, Ethiopia
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Abdelmenan S, Teka H, Hwang J, Girma S, Chibsa S, Tongren E, Murphy M, Haile M, Dillu D, Kassim J, Behaksra S, Tadesse FG, Yukich J, Berhane Y, Worku A, Keating J, Zewde A, Gadisa E. Evaluation of the effect of targeted Mass Drug Administration and Reactive Case Detection on malaria transmission and elimination in Eastern Hararghe zone, Oromia, Ethiopia: a cluster randomized control trial. Trials 2022; 23:267. [PMID: 35392979 PMCID: PMC8989114 DOI: 10.1186/s13063-022-06199-8] [Citation(s) in RCA: 0] [Impact Index Per Article: 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: 10/28/2021] [Accepted: 03/25/2022] [Indexed: 11/30/2022] Open
Abstract
Background Reactive and proactive case detection measures are widely implemented by national malaria elimination programs globally. Ethiopia decided to include Reactive Case Detection (RCD) and targeted Mass Drug Administration (tMDA) approaches as part of their elimination strategy along with rigorous evaluation. The purpose of this study is to compare the impact of RCD and tMDA on malaria elimination over the 2-year study period, by looking at the annual parasite incidence before and after the intervention. Methods The study will be conducted in the East Hararghe zone of Ethiopia. Malaria transmission in the area is low to moderate. This study will deploy a community-based, three-arm, cluster-randomized control trial implemented over 2 years. Forty-eight clusters (16 clusters per arm) will be selected based on the annual number of confirmed malaria cases seen in the cluster. All clusters will receive the current standard of care in terms of malaria elimination interventions provided by the national malaria control program. In addition, following the identification of malaria parasite infection, individuals who reside within a 100-m radius of the index case will receive a diagnosis for malaria and treatment if positive in the RCD arm or presumptive treatment in the tMDA arm. The primary effectiveness endpoint will be measured at baseline and endline for each intervention arm and compared to the control arm using a difference in difference approach. Discussion This randomized controlled trial will provide evidence of the impact of the proposed intervention approaches for malaria elimination. Trial registration ClinicalTrials.gov NCT04241705. Registration date: January 27, 2020.
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Affiliation(s)
- Semira Abdelmenan
- Addis Continental Institute of Public Health, Addis Ababa, Ethiopia.
| | - Hiwot Teka
- U.S. President's Malaria Initiative, Addis Ababa, Ethiopia
| | - Jimee Hwang
- U.S. Centers for Disease Control and Prevention, Atlanta, GA, USA
| | - Samuel Girma
- U.S. President's Malaria Initiative, Addis Ababa, Ethiopia
| | - Sheleme Chibsa
- U.S. President's Malaria Initiative, Addis Ababa, Ethiopia
| | - Eric Tongren
- U.S. Centers for Disease Control and Prevention, Addis Ababa, Ethiopia
| | - Matthew Murphy
- U.S. Centers for Disease Control and Prevention, Atlanta, GA, USA
| | | | | | - Jawar Kassim
- Oromia Regional Health Bureau, Addis Ababa, Ethiopia
| | | | | | | | - Yemane Berhane
- Addis Continental Institute of Public Health, Addis Ababa, Ethiopia
| | - Alemayehu Worku
- Addis Continental Institute of Public Health, Addis Ababa, Ethiopia
| | | | - Ayele Zewde
- Addis Continental Institute of Public Health, Addis Ababa, Ethiopia
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Amare A, Eshetu T, Lemma W. Dry-season transmission and determinants of Plasmodium infections in Jawi district, northwest Ethiopia. Malar J 2022; 21:45. [PMID: 35164768 PMCID: PMC8842575 DOI: 10.1186/s12936-022-04068-y] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/15/2021] [Accepted: 01/30/2022] [Indexed: 11/12/2022] Open
Abstract
Background Malaria remains a serious global public health problem, and continues to have a devastating impact on people’s health worldwide. Continuous monitoring and evaluation of current malaria transmission status in different seasons is a mainstay for the success of ongoing intervention strategies for malaria. The purpose of this study was to assess the dry-season transmission and determinants of malaria in Jawi district, northwest Ethiopia. Methods A community-based cross-sectional study was conducted from January 13 to February 11, 2020; among selected Kebeles in the Jawi district. A multistage sampling technique was used in this study. Random and systematic sampling techniques were carried out to select Kebeles and each household, respectively. Light microscopy and CareStart™ Malaria HRP2/pLDH (Pf/Pv) Combo RDT were implemented to determine the prevalence of malaria. Moreover, associated risk factors in the prevalence of malaria were assessed by using a bivariate and multivariate logistic regression model. Results A total of 219 study participants were enrolled in this study. Of the total enrolled individuals, malaria cases were found among 36 individuals with a positivity rate of 16.4% (95% CI 11.4–21.5). Plasmodium falciparum was the predominant species with an estimated prevalence of 87.0% in the study areas. Interrupted utilization of ITN (AOR = 4.411, 95% CI 1.401–13.880), using over 3 years older ITNs (AOR = 9.622, 95% CI 1.881–49.214), travel history (AOR = 12.703, 95% CI 2.441–66.114), living in a house with holes on the wall (AOR = 3.811, 95% CI 1.010–14.384), and living in a house with an eave (AOR = 4.23, 95% CI 1.065–16.801) significantly increased the probability of malaria positivity rate. Conclusion Malaria is still an important public health burden among individuals in the Jawi district. Interrupted utilization of ITNs, using over 3 years older ITNs, living in a house with holes on the wall, living in a house with an eave, and travel history were identified as the risk factors of malaria. Therefore, the District health office and Health extension workers should promote daily utilization of good ITNs and improve housing conditions to reduce malaria prevalence.
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Niyukuri D, Sinzinkayo D, Troth EV, Oduma CO, Barengayabo M, Ndereyimana M, Holzschuh A, Vera-Arias CA, Gebre Y, Badu K, Nyandwi J, Baza D, Juma E, Koepfli C. Performance of highly sensitive and conventional rapid diagnostic tests for clinical and subclinical Plasmodium falciparum infections, and hrp2/3 deletion status in Burundi. PLOS Glob Public Health 2022; 2:e0000828. [PMID: 36962426 PMCID: PMC10022336 DOI: 10.1371/journal.pgph.0000828] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/09/2022] [Accepted: 06/30/2022] [Indexed: 11/18/2022]
Abstract
Rapid diagnostic tests (RDTs) are a key tool for the diagnosis of malaria infections among clinical and subclinical individuals. Low-density infections, and deletions of the P. falciparum hrp2/3 genes (encoding the HRP2 and HRP3 proteins detected by many RDTs) present challenges for RDT-based diagnosis. The novel Rapigen Biocredit three-band Plasmodium falciparum HRP2/LDH RDT was evaluated among 444 clinical and 468 subclinical individuals in a high transmission setting in Burundi. Results were compared to the AccessBio CareStart HRP2 RDT, and qPCR with a sensitivity of <0.3 parasites/μL blood. Sensitivity compared to qPCR among clinical patients for the Biocredit RDT was 79.9% (250/313, either of HRP2/LDH positive), compared to 73.2% (229/313) for CareStart (P = 0.048). Specificity of the Biocredit was 82.4% compared to 96.2% for CareStart. Among subclinical infections, sensitivity was 72.3% (162/224) compared to 58.5% (131/224) for CareStart (P = 0.003), and reached 88.3% (53/60) in children <15 years. Specificity was 84.4% for the Biocredit and 93.4% for the CareStart RDT. No (0/362) hrp2 and 2/366 hrp3 deletions were observed. In conclusion, the novel RDT showed improved sensitivity for the diagnosis of P. falciparum.
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Affiliation(s)
- David Niyukuri
- Doctoral School, University of Burundi, Bujumbura, Burundi
- South African DSI-NRF Centre of Excellence in Epidemiological Modelling and Analysis, Stellenbosch University, Stellenbosch, South Africa
| | - Denis Sinzinkayo
- Doctoral School, University of Burundi, Bujumbura, Burundi
- National Malaria Control Program, Bujumbura, Burundi
| | - Emma V Troth
- Eck Institute for Global Health and Department of Biological Sciences, University of Notre Dame, Notre Dame, Indiana, United States of America
| | | | | | | | - Aurel Holzschuh
- Eck Institute for Global Health and Department of Biological Sciences, University of Notre Dame, Notre Dame, Indiana, United States of America
| | - Claudia A Vera-Arias
- Eck Institute for Global Health and Department of Biological Sciences, University of Notre Dame, Notre Dame, Indiana, United States of America
| | - Yilekal Gebre
- Eck Institute for Global Health and Department of Biological Sciences, University of Notre Dame, Notre Dame, Indiana, United States of America
| | - Kingsley Badu
- Kwame Nkrumah University of Science and Technology, Kumasi, Ghana
| | - Joseph Nyandwi
- Doctoral School, University of Burundi, Bujumbura, Burundi
- National Institute of Public Health, Bujumbura, Burundi
| | | | | | - Cristian Koepfli
- Eck Institute for Global Health and Department of Biological Sciences, University of Notre Dame, Notre Dame, Indiana, United States of America
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McMahon A, Mihretie A, Ahmed AA, Lake M, Awoke W, Wimberly MC. Remote sensing of environmental risk factors for malaria in different geographic contexts. Int J Health Geogr 2021; 20:28. [PMID: 34120599 PMCID: PMC8201719 DOI: 10.1186/s12942-021-00282-0] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/25/2021] [Accepted: 06/03/2021] [Indexed: 11/15/2022] Open
Abstract
BACKGROUND Despite global intervention efforts, malaria remains a major public health concern in many parts of the world. Understanding geographic variation in malaria patterns and their environmental determinants can support targeting of malaria control and development of elimination strategies. METHODS We used remotely sensed environmental data to analyze the influences of environmental risk factors on malaria cases caused by Plasmodium falciparum and Plasmodium vivax from 2014 to 2017 in two geographic settings in Ethiopia. Geospatial datasets were derived from multiple sources and characterized climate, vegetation, land use, topography, and surface water. All data were summarized annually at the sub-district (kebele) level for each of the two study areas. We analyzed the associations between environmental data and malaria cases with Boosted Regression Tree (BRT) models. RESULTS We found considerable spatial variation in malaria occurrence. Spectral indices related to land cover greenness (NDVI) and moisture (NDWI) showed negative associations with malaria, as the highest malaria rates were found in landscapes with low vegetation cover and moisture during the months that follow the rainy season. Climatic factors, including precipitation and land surface temperature, had positive associations with malaria. Settlement structure also played an important role, with different effects in the two study areas. Variables related to surface water, such as irrigated agriculture, wetlands, seasonally flooded waterbodies, and height above nearest drainage did not have strong influences on malaria. CONCLUSION We found different relationships between malaria and environmental conditions in two geographically distinctive areas. These results emphasize that studies of malaria-environmental relationships and predictive models of malaria occurrence should be context specific to account for such differences.
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Affiliation(s)
- Andrea McMahon
- Department of Geography and Environmental Sustainability, University of Oklahoma, Norman, OK USA
| | - Abere Mihretie
- Health, Development, and Anti-Malaria Association, Addis Ababa, Ethiopia
| | - Adem Agmas Ahmed
- Malaria Control and Elimination Partnership in Africa, Bahir Dar, Ethiopia
| | | | - Worku Awoke
- School of Public Health, Bahir Dar University, Bahir Dar, Ethiopia
| | - Michael Charles Wimberly
- Department of Geography and Environmental Sustainability, University of Oklahoma, Norman, OK USA
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Galatas B, Mayor A, Gupta H, Balanza N, Jang IK, Nhamussua L, Simone W, Cisteró P, Chidimatembue A, Munguambe H, Saúte F, Aide P, Bassat Q. Field performance of ultrasensitive and conventional malaria rapid diagnostic tests in southern Mozambique. Malar J 2020; 19:451. [PMID: 33287822 PMCID: PMC7720469 DOI: 10.1186/s12936-020-03526-9] [Citation(s) in RCA: 9] [Impact Index Per Article: 2.3] [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: 08/26/2020] [Accepted: 11/26/2020] [Indexed: 01/01/2023] Open
Abstract
Background An ultrasensitive malaria rapid diagnostic test (RDT) was recently developed for the improved detection of low-density Plasmodium falciparum infections. This study aimed to compare the diagnostic performance of the PfHRP2-based Abbott Malaria Ag P. falciparum ultrasensitive RDT (uRDT) to that of the conventional SD-Bioline Malaria Ag P. falciparum RDT (cRDT) when performed under field conditions. Methods Finger-prick blood samples were collected from adults and children in two cross-sectional surveys in May of 2017 in southern Mozambique. Using real-time quantitative PCR (RT-qPCR) as the reference method, the age-specific diagnostic performance indicators of the cRDT and uRDT were compared. The presence of histidine-rich protein 2 (HRP2) and Plasmodium lactate dehydrogenase (pLDH) antigens was evaluated in a subset from dried blood spots by a quantitative antigen assay. pfhrp2 and pfhrp3 gene deletions were assessed in samples positive by RT-qPCR and negative by both RDTs. Results Among the 4,396 participants with complete test results, the sensitivity of uRDTs (68.2; 95% CI 60.8 to 74.9) was marginally better than that of cRDTs (61.5; 95% CI 53.9 to 68.6) (p-value = 0.004), while the specificities were similar (uRDT: 99.0 [95% CI 98.6 to 99.2], cRDT: 99.2 [95% CI 98.9 to 99.4], p-value = 0.02). While the performance of both RDTs was lowest in ≥ 15-year-olds, driven by the higher prevalence of low parasite density infections in this group, the sensitivity of uRDTs was significantly higher in this age group (54.9, 95% CI 40.3 to 68.9) compared to the sensitivity of cRDTs (39.2, 95% CI 25.8 to 53.9) (p-value = 0.008). Both RDTs detected P. falciparum infections at similar geometric mean parasite densities (112.9 parasites/μL for uRDTs and 145.5 parasites/μL for cRDTs). The presence of HRP2 antigen was similar among false positive (FP) samples of both tests (80.5% among uRDT-FPs and 84.4% among cRDT-FPs). Only one false negative sample was detected with a partial pfhrp2 deletion. Conclusion This study showed that the uRDTs developed by Abbott do not substantially outperform SD-Bioline Pf malaria RDTs in the community and are still not comparable to molecular methods to detect P. falciparum infections in this study setting.
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Affiliation(s)
- Beatriz Galatas
- ISGlobal, Hospital Clínic - Universitat de Barcelona, Barcelona, Spain. .,Centro de Investigação em Saúde de Manhiça, Maputo, Mozambique.
| | - Alfredo Mayor
- ISGlobal, Hospital Clínic - Universitat de Barcelona, Barcelona, Spain.,Centro de Investigação em Saúde de Manhiça, Maputo, Mozambique.,CIBER Epidemiología y Salud Pública (CIBERESP), Madrid, Spain
| | - Himanshu Gupta
- ISGlobal, Hospital Clínic - Universitat de Barcelona, Barcelona, Spain.,Department of Infection Biology, Faculty of Infectious and Tropical Diseases, London School of Hygiene and Tropical Medicine, London, UK
| | - Núria Balanza
- ISGlobal, Hospital Clínic - Universitat de Barcelona, Barcelona, Spain
| | | | - Lidia Nhamussua
- Centro de Investigação em Saúde de Manhiça, Maputo, Mozambique
| | - Wilson Simone
- Centro de Investigação em Saúde de Manhiça, Maputo, Mozambique
| | - Pau Cisteró
- ISGlobal, Hospital Clínic - Universitat de Barcelona, Barcelona, Spain
| | | | | | - Francisco Saúte
- Centro de Investigação em Saúde de Manhiça, Maputo, Mozambique
| | - Pedro Aide
- Centro de Investigação em Saúde de Manhiça, Maputo, Mozambique.,National Institute of Health, Ministry of Health, Maputo, Mozambique
| | - Quique Bassat
- ISGlobal, Hospital Clínic - Universitat de Barcelona, Barcelona, Spain.,Centro de Investigação em Saúde de Manhiça, Maputo, Mozambique.,CIBER Epidemiología y Salud Pública (CIBERESP), Madrid, Spain.,ICREA, Pg. Lluís Companys 23, 08010, Barcelona, Spain.,Pediatric Infectious Diseases Unit, Pediatrics Department, Hospital Sant Joan de Déu (University of Barcelona), Barcelona, Spain
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Ahmed S, Reithinger R, Kaptoge SK, Ngondi JM. Travel Is a Key Risk Factor for Malaria Transmission in Pre-Elimination Settings in Sub-Saharan Africa: A Review of the Literature and Meta-Analysis. Am J Trop Med Hyg 2020; 103:1380-1387. [PMID: 32815497 PMCID: PMC7543864 DOI: 10.4269/ajtmh.18-0456] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/03/2022] Open
Abstract
By sustaining transmission or causing malaria outbreaks, imported malaria undermines malaria elimination efforts. Few studies have examined the impact of travel on malaria epidemiology. We conducted a literature review and meta-analysis of studies investigating travel as a risk factor for malaria infection in sub-Saharan Africa using PubMed. We identified 22 studies and calculated a random-effects meta-analysis pooled odds ratio (OR) of 3.77 (95% CI: 2.49–5.70), indicating that travel is a significant risk factor for malaria infection. Odds ratios were particularly high in urban locations when travel was to rural areas, to more endemic/high transmission areas, and in young children. Although there was substantial heterogeneity in the magnitude of association across the studies, the pooled estimate and directional consistency support travel as an important risk factor for malaria infection.
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Affiliation(s)
- Sundus Ahmed
- Institute of Public Health, University of Cambridge, Cambridge, United Kingdom
| | | | - Stephen K Kaptoge
- Institute of Public Health, University of Cambridge, Cambridge, United Kingdom
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Sutanto I, Kosasih A, Elyazar IRF, Simanjuntak DR, Larasati TA, Dahlan MS, Wahid I, Mueller I, Koepfli C, Kusriastuti R, Surya A, Laihad FJ, Hawley WA, Collins FH, Baird JK, Lobo NF. Negligible Impact of Mass Screening and Treatment on Mesoendemic Malaria Transmission at West Timor in Eastern Indonesia: A Cluster-Randomized Trial. Clin Infect Dis 2019; 67:1364-1372. [PMID: 29579195 PMCID: PMC6186863 DOI: 10.1093/cid/ciy231] [Citation(s) in RCA: 24] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/03/2017] [Accepted: 03/21/2018] [Indexed: 01/09/2023] Open
Abstract
Background Mass screening and treatment (MST) aims to reduce malaria risk in communities by identifying and treating infected persons without regard to illness. Methods A cluster-randomized trial evaluated malaria incidence with and without MST. Clusters were randomized to 3, 2, or no MST interventions: MST3, 6 clusters (156 households/670 individuals); MST2, 5 clusters (89 households/423 individuals); and MST0, 5 clusters (174 households/777 individuals). All clusters completed the study with 14 residents withdrawing. In a cohort of 324 schoolchildren (MST3, n = 124; MST2, n = 57; MST0, n = 143) negative by microscopy at enrollment, we evaluated the incidence density of malaria during 3 months of MST and 3 months following. The MST intervention involved community-wide expert malaria microscopic screening and standard therapy with dihydroartemisinin-piperaquine and primaquine for glucose-6 phosphate dehydrogenase–normal subjects. All blood examinations included polymerase chain reaction assays, which did not guide on-site treatment. Results The risk ratios for incidence density of microscopically patent malaria in MST3 or MST2 relative to that in MST0 clusters were 1.00 (95% confidence interval [CI], .53–1.91) and 1.22 (95% CI, .42–3.55), respectively. Similar results were obtained with molecular analysis and species-specific (P. falciparum and P. vivax) infections. Microscopically subpatent, untreated infections accounted for 72% of those infected. Conclusions Two or 3 rounds of MST within 3 months did not impact the force of anopheline mosquito-borne infection in these communities. The high rate of untreated microscopically subpatent infections likely explains the observed poor impact. Clinical Trials Registration NCT01878357.
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Affiliation(s)
- Inge Sutanto
- Department of Parasitology, Faculty of Medicine, University of Indonesia, Indonesia
| | - Ayleen Kosasih
- Department of Parasitology, Faculty of Medicine, University of Indonesia, Indonesia
| | | | - Deddy R Simanjuntak
- Department of Parasitology, Faculty of Medicine, University of Indonesia, Indonesia
| | - Tri A Larasati
- Department of Parasitology, Faculty of Medicine, University of Indonesia, Indonesia
| | | | - Isra Wahid
- Department of Parasitology, Faculty of Medicine, University of Hasanudin, Makasar, Indonesia
| | - Ivo Mueller
- Population Health and Immunity Division, Walter and Eliza Hall Institute, Melbourne, Victoria, Australia
| | - Cristian Koepfli
- Population Health and Immunity Division, Walter and Eliza Hall Institute, Melbourne, Victoria, Australia
| | - Rita Kusriastuti
- Communicable Disease Control, Ministry of Health, Jakarta, Indonesia
| | - Asik Surya
- Communicable Disease Control, Ministry of Health, Jakarta, Indonesia
| | | | | | - Frank H Collins
- Eck Institute for Global Health, University of Notre Dame, Indiana
| | - J Kevin Baird
- Eijkman-Oxford Clinical Research Unit, Indonesia.,Center for Tropical Medicine and Global Health, Nuffield Department of Medicine, University of Oxford, United Kingdom
| | - Neil F Lobo
- Eck Institute for Global Health, University of Notre Dame, Indiana
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11
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Mwesigwa J, Slater H, Bradley J, Saidy B, Ceesay F, Whittaker C, Kandeh B, Nkwakamna D, Drakeley C, Van Geertruyden JP, Bousema T, Achan J, D’Alessandro U. Field performance of the malaria highly sensitive rapid diagnostic test in a setting of varying malaria transmission. Malar J 2019; 18:288. [PMID: 31455349 PMCID: PMC6712604 DOI: 10.1186/s12936-019-2929-1] [Citation(s) in RCA: 21] [Impact Index Per Article: 4.2] [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: 03/30/2019] [Accepted: 08/22/2019] [Indexed: 12/14/2022] Open
Abstract
BACKGROUND The Gambia has successfully reduced malaria transmission. The human reservoir of infection could further decrease if malaria-infected individuals could be identified by highly sensitive, field-based, diagnostic tools and then treated. METHODS A cross-sectional survey was done at the peak of the 2017 malaria season in 47 Gambian villages. From each village, 100 residents were randomly selected for finger-prick blood samples to detect Plasmodium falciparum infections using highly sensitive rapid diagnostic tests (HS-RDT) and PCR. The sensitivity and specificity of the HS-RDT were estimated (assuming PCR as the gold standard) across varying transmission intensities and in different age groups. A deterministic, age-structured, dynamic model of malaria transmission was used to estimate the impact of mass testing and treatment (MTAT) with HS-RDT in four different scenarios of malaria prevalence by PCR: 5, 15, 30, and 60%, and with seasonal transmission. The impact was compared both to MTAT with conventional RDT and mass drug administration (MDA). RESULTS Malaria prevalence by HS-RDT was 15% (570/3798; 95% CI 13.9-16.1). The HS-RDT sensitivity and specificity were 38.4% (191/497, 95% CI 34.2-42.71) and 88.5% (2922/3301; 95% CI 87.4-89.6), respectively. Sensitivity was the highest (50.9%, 95% CI 43.3-58.5%) in high prevalence villages (20-50% by PCR). The model predicted that in very low transmission areas (≤ 5%), three monthly rounds of MTAT with HS-RDT, starting towards the end of the dry season and testing 65 or 85% of the population for 2 consecutive years, would avert 62 or 78% of malaria cases (over 2 years), respectively. The effect of the intervention would be lower in a moderate transmission setting. In all settings, MDA would be superior to MTAT with HS-RDT which would be superior to MTAT with conventional RDT. CONCLUSION The HS-RDT's field sensitivity was modest and varied by transmission intensity. In low to very low transmission areas, three monthly rounds per year of MTAT with HS-RDT at 85% coverage for 2 consecutive years would reduce malaria prevalence to such low levels that additional strategies may achieve elimination. The model prediction would need to be confirmed by cluster-randomized trials.
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Affiliation(s)
- Julia Mwesigwa
- 0000 0004 0606 294Xgrid.415063.5Medical Research Council Unit The Gambia at London School of Hygiene and Tropical Medicine, P.O. Box 273, Banjul, The Gambia
| | - Hannah Slater
- 0000 0001 2113 8111grid.7445.2MRC Centre for Global Disease Analysis, Department of Infectious Disease Epidemiology, Imperial College London, London, Norfolk Place, London, W2 1P UK ,0000 0000 8940 7771grid.415269.dPATH, 2201 Westlake Avenue, Seattle, USA
| | - John Bradley
- 0000 0004 0425 469Xgrid.8991.9MRC Tropical Epidemiology Group, London School of Hygiene and Tropical Medicine, London, UK
| | - Binta Saidy
- 0000 0004 0606 294Xgrid.415063.5Medical Research Council Unit The Gambia at London School of Hygiene and Tropical Medicine, P.O. Box 273, Banjul, The Gambia
| | - Fatima Ceesay
- 0000 0004 0606 294Xgrid.415063.5Medical Research Council Unit The Gambia at London School of Hygiene and Tropical Medicine, P.O. Box 273, Banjul, The Gambia
| | - Charles Whittaker
- 0000 0001 2113 8111grid.7445.2MRC Centre for Global Disease Analysis, Department of Infectious Disease Epidemiology, Imperial College London, London, Norfolk Place, London, W2 1P UK
| | | | - Davis Nkwakamna
- 0000 0004 0606 294Xgrid.415063.5Medical Research Council Unit The Gambia at London School of Hygiene and Tropical Medicine, P.O. Box 273, Banjul, The Gambia
| | - Chris Drakeley
- 0000 0004 0425 469Xgrid.8991.9Department of Immunology and Infection, Faculty of Infectious Diseases and Tropical Medicine, London School of Hygiene and Tropical Medicine, London, UK
| | - Jean-Pierre Van Geertruyden
- 0000 0001 0790 3681grid.5284.bFaculty of Medicine and Health Sciences, University of Antwerp, Antwerp, Belgium
| | - Teun Bousema
- 0000 0004 0444 9382grid.10417.33Radboud Institute for Health Sciences, Radboud University Medical Center, Nijmegen, The Netherlands
| | - Jane Achan
- 0000 0004 0606 294Xgrid.415063.5Medical Research Council Unit The Gambia at London School of Hygiene and Tropical Medicine, P.O. Box 273, Banjul, The Gambia
| | - Umberto D’Alessandro
- 0000 0004 0606 294Xgrid.415063.5Medical Research Council Unit The Gambia at London School of Hygiene and Tropical Medicine, P.O. Box 273, Banjul, The Gambia
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12
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Assefa A, Ali Ahmed A, Deressa W, Sime H, Mohammed H, Kebede A, Solomon H, Teka H, Gurrala K, Matei B, Wakeman B, Wilson GG, Sinha I, Maude RJ, Ashton R, Cook J, Shi YP, Drakeley C, von Seidlein L, Rogier E, Hwang J. Multiplex serology demonstrate cumulative prevalence and spatial distribution of malaria in Ethiopia. Malar J 2019; 18:246. [PMID: 31331340 PMCID: PMC6647069 DOI: 10.1186/s12936-019-2874-z] [Citation(s) in RCA: 24] [Impact Index Per Article: 4.8] [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: 03/13/2019] [Accepted: 07/07/2019] [Indexed: 11/26/2022] Open
Abstract
Background Measures of malaria burden using microscopy and rapid diagnostic tests (RDTs) in cross-sectional household surveys may incompletely describe the burden of malaria in low-transmission settings. This study describes the pattern of malaria transmission in Ethiopia using serological antibody estimates derived from a nationwide household survey completed in 2015. Methods Dried blood spot (DBS) samples were collected during the Ethiopian Malaria Indicator Survey in 2015 from malarious areas across Ethiopia. Samples were analysed using bead-based multiplex assays for IgG antibodies for six Plasmodium antigens: four human malaria species-specific merozoite surface protein-1 19kD antigens (MSP-1) and Apical Membrane Antigen-1 (AMA-1) for Plasmodium falciparum and Plasmodium vivax. Seroprevalence was estimated by age, elevation and region. The seroconversion rate was estimated using a reversible catalytic model fitted with maximum likelihood methods. Results Of the 10,278 DBS samples available, 93.6% (9622/10,278) had valid serological results. The mean age of participants was 15.8 years and 53.3% were female. National seroprevalence for antibodies to P. falciparum was 32.1% (95% confidence interval (CI) 29.8–34.4) and 25.0% (95% CI 22.7–27.3) to P. vivax. Estimated seroprevalences for Plasmodium malariae and Plasmodium ovale were 8.6% (95% CI 7.6–9.7) and 3.1% (95% CI 2.5–3.8), respectively. For P. falciparum seroprevalence estimates were significantly higher at lower elevations (< 2000 m) compared to higher (2000–2500 m) (aOR 4.4; p < 0.01). Among regions, P. falciparum seroprevalence ranged from 11.0% (95% CI 8.8–13.7) in Somali to 65.0% (95% CI 58.0–71.4) in Gambela Region and for P. vivax from 4.0% (95% CI 2.6–6.2) in Somali to 36.7% (95% CI 30.0–44.1) in Amhara Region. Models fitted to measure seroconversion rates showed variation nationally and by elevation, region, antigen type, and within species. Conclusion Using multiplex serology assays, this study explored the cumulative malaria burden and regional dynamics of the four human malarias in Ethiopia. High malaria burden was observed in the northwest compared to the east. High transmission in the Gambela and Benishangul-Gumuz Regions and the neglected presence of P. malariae and P. ovale may require programmatic attention. The use of a multiplex assay for antibody detection in low transmission settings has the potential to act as a more sensitive biomarker. Electronic supplementary material The online version of this article (10.1186/s12936-019-2874-z) contains supplementary material, which is available to authorized users.
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Affiliation(s)
- Ashenafi Assefa
- Ethiopian Public Health Institute, Addis Ababa, Ethiopia. .,School of Public Health, Addis Ababa University, Addis Ababa, Ethiopia.
| | - Ahmed Ali Ahmed
- School of Public Health, Addis Ababa University, Addis Ababa, Ethiopia
| | - Wakgari Deressa
- School of Public Health, Addis Ababa University, Addis Ababa, Ethiopia
| | - Heven Sime
- Ethiopian Public Health Institute, Addis Ababa, Ethiopia
| | | | - Amha Kebede
- African Society for Laboratory Medicine, Addis Ababa, Ethiopia
| | - Hiwot Solomon
- Ethiopian Federal Ministry of Health, Addis Ababa, Ethiopia
| | - Hiwot Teka
- U.S. President's Malaria Initiative, United States Agency for International Development, Addis Ababa, Ethiopia
| | - Kevin Gurrala
- Malaria Branch, Division of Parasitic Diseases and Malaria, Centers for Disease Control and Prevention, Atlanta, GA, USA
| | - Brian Matei
- Malaria Branch, Division of Parasitic Diseases and Malaria, Centers for Disease Control and Prevention, Atlanta, GA, USA
| | - Brian Wakeman
- Malaria Branch, Division of Parasitic Diseases and Malaria, Centers for Disease Control and Prevention, Atlanta, GA, USA
| | - G Glenn Wilson
- Department of Biology, University of Southern Denmark, 5230, Odense M, Denmark
| | - Ipsita Sinha
- Mahidol Oxford Research Unit, Mahidol University, Bangkok, Thailand.,Centre for Tropical Medicine and Global Health, Nuffield Department of Medicine, University of Oxford, Oxford, UK
| | - Richard J Maude
- Mahidol Oxford Research Unit, Mahidol University, Bangkok, Thailand.,Centre for Tropical Medicine and Global Health, Nuffield Department of Medicine, University of Oxford, Oxford, UK.,Harvard TH Chan School of Public Health, Harvard University, Boston, USA
| | - Ruth Ashton
- Center for Applied Malaria Research and Evaluation, Tulane School of Public Health and Tropical Medicine, New Orleans, LA, USA
| | - Jackie Cook
- London School of Hygiene and Tropical Medicine, London, UK
| | - Ya Ping Shi
- Malaria Branch, Division of Parasitic Diseases and Malaria, Centers for Disease Control and Prevention, Atlanta, GA, USA
| | - Chris Drakeley
- London School of Hygiene and Tropical Medicine, London, UK
| | - Lorenz von Seidlein
- Mahidol Oxford Research Unit, Mahidol University, Bangkok, Thailand.,Centre for Tropical Medicine and Global Health, Nuffield Department of Medicine, University of Oxford, Oxford, UK
| | - Eric Rogier
- Malaria Branch, Division of Parasitic Diseases and Malaria, Centers for Disease Control and Prevention, Atlanta, GA, USA
| | - Jimee Hwang
- Malaria Branch, Division of Parasitic Diseases and Malaria, U.S. President's Malaria Initiative, Centers for Disease Control and Prevention, Atlanta, GA, USA
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13
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Bansil P, Yeshiwondim AK, Guinovart C, Serda B, Scott C, Tesfay BH, Agmas A, Bezabih B, Zeleke MT, Guesses GS, Ayenew AL, Workie WM, Earle D, Steketee RW, Getachew A. Malaria case investigation with reactive focal testing and treatment: operational feasibility and lessons learned from low and moderate transmission areas in Amhara Region, Ethiopia. Malar J 2018; 17:449. [PMID: 30514307 PMCID: PMC6278130 DOI: 10.1186/s12936-018-2587-8] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.2] [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: 09/06/2018] [Accepted: 11/22/2018] [Indexed: 12/11/2022] Open
Abstract
BACKGROUND When malaria transmission is very low, investigation of passively detected malaria cases and reactive focal testing and treatment (FTAT) in the case and neighbouring households can identify and contain the source and spread of infections. METHODS Case investigation with reactive FTAT for malaria was implemented in 10 villages in Amhara Region, Ethiopia during the 2014/2015 malaria transmission season. Intervention villages were purposively selected based on the incidence of passively detected Plasmodium falciparum and mixed infections (P. falciparum and Plasmodium vivax) during the 2013 transmission season. A passively detected P. falciparum or mixed index case triggered an investigation that targeted the index case household and the closest 10 neighbouring households in a 100-m radius. All consenting household members received a rapid diagnostic test (RDT) and RDT-positive individuals received artemether-lumefantrine (P. falciparum, mixed) or chloroquine (P. vivax). RESULTS From October 2014 to February 2015, 407 P. falciparum or mixed index cases (approximately 6.5 per 1000 population) were passively detected. Of these, 220 (54.1%) were investigated, of which 87.3% were male, 61.8% were age 20-39 years [median age: 27 years (range 1-90)], and 58.6% spent ≥ 1 night away from home in the past month (ranging from 0.0 to 94.1% by village). Among the 4077 residents in the 914 households investigated, 3243 (79.5%) received an RDT and 127 (3.9%) were RDT-positive (2.2% P. falciparum, 0.5% P. vivax, 1.2% mixed). Three epidemiological patterns were found. In six villages, there were almost no cases, with less than 10 index and secondary cases. In three villages, most index cases had a history of travel (> 62%), but there were a small number of secondary cases (< 10). Lastly, in one village none of the index cases had a history of recent travel and there was a large number of secondary cases (n = 105). CONCLUSIONS Three types of malaria transmission patterns were observed: (1) low importation and low local transmission; (2) high importation and low local transmission; and, (3) low importation and high local transmission. To achieve malaria elimination in Amhara Region, intervention strategies targeting these different patterns of transmission and population movement are required.
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Affiliation(s)
- Pooja Bansil
- PATH Malaria Control and Elimination Partnership in Africa (MACEPA), 2201 Westlake Avenue, Suite 200, Seattle, WA, 98121, USA.
| | - Asnakew K Yeshiwondim
- PATH Malaria Control and Elimination Partnership in Africa (MACEPA), Addis Ababa, Ethiopia
| | - Caterina Guinovart
- PATH Malaria Control and Elimination Partnership in Africa (MACEPA), 2201 Westlake Avenue, Suite 200, Seattle, WA, 98121, USA
| | - Belendia Serda
- PATH Malaria Control and Elimination Partnership in Africa (MACEPA), Addis Ababa, Ethiopia
| | - Callie Scott
- PATH Malaria Control and Elimination Partnership in Africa (MACEPA), 2201 Westlake Avenue, Suite 200, Seattle, WA, 98121, USA
| | - Berhane H Tesfay
- PATH Malaria Control and Elimination Partnership in Africa (MACEPA), Addis Ababa, Ethiopia
| | - Adem Agmas
- PATH Malaria Control and Elimination Partnership in Africa (MACEPA), Addis Ababa, Ethiopia
| | - Belay Bezabih
- Amhara National Regional State Health Bureau, Bahir Dar, Ethiopia
| | - Melkamu T Zeleke
- PATH Malaria Control and Elimination Partnership in Africa (MACEPA), Addis Ababa, Ethiopia
| | - Girma S Guesses
- PATH Malaria Control and Elimination Partnership in Africa (MACEPA), Addis Ababa, Ethiopia
| | - Asmamaw L Ayenew
- PATH Malaria Control and Elimination Partnership in Africa (MACEPA), Addis Ababa, Ethiopia
| | - Worku M Workie
- PATH Malaria Control and Elimination Partnership in Africa (MACEPA), Addis Ababa, Ethiopia
| | - Duncan Earle
- PATH Malaria Control and Elimination Partnership in Africa (MACEPA), 2201 Westlake Avenue, Suite 200, Seattle, WA, 98121, USA
| | - Rick W Steketee
- PATH Malaria Control and Elimination Partnership in Africa (MACEPA), 2201 Westlake Avenue, Suite 200, Seattle, WA, 98121, USA
| | - Asefaw Getachew
- PATH Malaria Control and Elimination Partnership in Africa (MACEPA), Addis Ababa, Ethiopia
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14
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Yalew WG, Pal S, Bansil P, Dabbs R, Tetteh K, Guinovart C, Kalnoky M, Serda BA, Tesfay BH, Beyene BB, Seneviratne C, Littrell M, Yokobe L, Noland GS, Domingo GJ, Getachew A, Drakeley C, Steketee RW. Current and cumulative malaria infections in a setting embarking on elimination: Amhara, Ethiopia. Malar J 2017; 16:242. [PMID: 28595603 PMCID: PMC5465535 DOI: 10.1186/s12936-017-1884-y] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.4] [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: 03/03/2017] [Accepted: 05/30/2017] [Indexed: 11/17/2022] Open
Abstract
Background Since 2005, Ethiopia has aggressively scaled up malaria prevention and case management. As a result, the number of malaria cases and deaths has significantly declined. In order to track progress towards the elimination of malaria in Amhara Region, coverage of malaria control tools and current malaria transmission need to be documented. Methods A cross-sectional household survey oversampling children under 5 years of age was conducted during the dry season in 2013. A bivalent rapid diagnostic test (RDT) detecting both Plasmodium falciparum and Plasmodium vivax and serology assays using merozoite antigens from both these species were used to assess the prevalence of malaria infections and exposure to malaria parasites in 16 woredas (districts) in Amhara Region. Results 7878 participants were included, with a mean age of 16.8 years (range 0.5–102.8 years) and 42.0% being children under 5 years of age. The age-adjusted RDT-positivity for P. falciparum and P. vivax infection was 1.5 and 0.4%, respectively, of which 0.05% presented as co-infections. Overall age-adjusted seroprevalence was 30.0% for P. falciparum, 21.8% for P. vivax, and seroprevalence for any malaria species was 39.4%. The prevalence of RDT-positive infections varied by woreda, ranging from 0.0 to 8.3% and by altitude with rates of 3.2, 0.7, and 0.4% at under 2000, 2000–2500, and >2500 m, respectively. Serological analysis showed heterogeneity in transmission intensity by area and altitude and evidence for a change in the force of infection in the mid-2000s. Conclusions Current and historic malaria transmission across Amhara Region show substantial variation by age and altitude with some settings showing very low or near-zero transmission. Plasmodium vivax infections appear to be lower but relatively more stable across geography and altitude, while P. falciparum is the dominant infection in the higher transmission, low-altitude areas. Age-dependent seroprevalence analyses indicates a drop in transmission occurred in the mid-2000s, coinciding with malaria control scale-up efforts. As malaria parasitaemia rates get very low with elimination efforts, serological evaluation may help track progress to elimination. Electronic supplementary material The online version of this article (doi:10.1186/s12936-017-1884-y) contains supplementary material, which is available to authorized users.
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Affiliation(s)
- Woyneshet G Yalew
- Regional Health Research Laboratory Center, Amhara National Regional State Health Bureau, P.O. Box 495, Bahir Dar, Ethiopia
| | - Sampa Pal
- PATH, 2201 Westlake Avenue, Suite 200, Seattle, WA, 98121, USA
| | - Pooja Bansil
- PATH, 2201 Westlake Avenue, Suite 200, Seattle, WA, 98121, USA
| | - Rebecca Dabbs
- Faculty of Infectious and Tropical Diseases, London School of Tropical Medicine and Hygiene, Keppel Street, London, WCIE 7HT, UK
| | - Kevin Tetteh
- Faculty of Infectious and Tropical Diseases, London School of Tropical Medicine and Hygiene, Keppel Street, London, WCIE 7HT, UK
| | | | - Michael Kalnoky
- PATH, 2201 Westlake Avenue, Suite 200, Seattle, WA, 98121, USA
| | | | | | - Belay B Beyene
- Regional Health Research Laboratory Center, Amhara National Regional State Health Bureau, P.O. Box 495, Bahir Dar, Ethiopia
| | | | - Megan Littrell
- PATH, 2201 Westlake Avenue, Suite 200, Seattle, WA, 98121, USA
| | - Lindsay Yokobe
- PATH, 2201 Westlake Avenue, Suite 200, Seattle, WA, 98121, USA
| | | | | | - Asefaw Getachew
- PATH, 2201 Westlake Avenue, Suite 200, Seattle, WA, 98121, USA
| | - Chris Drakeley
- Faculty of Infectious and Tropical Diseases, London School of Tropical Medicine and Hygiene, Keppel Street, London, WCIE 7HT, UK
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15
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Vajda ÉA, Webb CE. Assessing the Risk Factors Associated with Malaria in the Highlands of Ethiopia: What Do We Need to Know? Trop Med Infect Dis 2017; 2:E4. [PMID: 30270863 DOI: 10.3390/tropicalmed2010004] [Citation(s) in RCA: 22] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/07/2016] [Revised: 02/23/2017] [Accepted: 02/25/2017] [Indexed: 12/13/2022] Open
Abstract
Malaria has been Ethiopia's predominant communicable disease for decades. Following the catastrophic malaria outbreak in 2003⁻2004, the Federal Ministry of Health (FMoH) took drastic public health actions to lower the burden of malaria. The FMoH achieved significant declines in malaria mortality and incidence, and recently declared its objective to achieve malaria elimination in low malaria transmission areas of Ethiopia by 2020. However, while the overall malaria prevalence has decreased, unpredictable outbreaks increasingly occur irregularly in regions previously considered "malaria-free". Such outbreaks have disastrous consequences on populations of these regions as they have no immunity against malaria. The Amhara Region accounts for 31% of Ethiopia's malaria burden and is targeted for malaria elimination by the FMoH. Amhara's epidemiological surveillance system faces many challenges to detect in a timely manner the unpredictable and irregular malaria outbreaks that occur in areas of otherwise low transmission. Despite the evidence of a shift in malaria transmission patterns, Amhara's malaria control interventions remain constrained to areas that are historically known to have stable malaria transmission. This paper discusses the influence of temperature and precipitation variability, entomological parameters, and human population mobility on malaria transmission patterns across the Amhara Region, and in particular, in areas of unstable transmission. We argue that malaria epidemiological surveillance systems can be improved by accounting for population movements in addition to environmental and entomological factors. However, to date, no study has statistically analyzed the interplay of population dynamics on environmental and entomological drivers of malaria transmission.
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16
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Merkord CL, Liu Y, Mihretie A, Gebrehiwot T, Awoke W, Bayabil E, Henebry GM, Kassa GT, Lake M, Wimberly MC. Integrating malaria surveillance with climate data for outbreak detection and forecasting: the EPIDEMIA system. Malar J 2017; 16:89. [PMID: 28231803 PMCID: PMC5324298 DOI: 10.1186/s12936-017-1735-x] [Citation(s) in RCA: 24] [Impact Index Per Article: 3.4] [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: 10/15/2016] [Accepted: 02/11/2017] [Indexed: 11/19/2022] Open
Abstract
Background Early indication of an emerging malaria epidemic can provide an opportunity for proactive interventions. Challenges to the identification of nascent malaria epidemics include obtaining recent epidemiological surveillance data, spatially and temporally harmonizing this information with timely data on environmental precursors, applying models for early detection and early warning, and communicating results to public health officials. Automated web-based informatics systems can provide a solution to these problems, but their implementation in real-world settings has been limited. Methods The Epidemic Prognosis Incorporating Disease and Environmental Monitoring for Integrated Assessment (EPIDEMIA) computer system was designed and implemented to integrate disease surveillance with environmental monitoring in support of operational malaria forecasting in the Amhara region of Ethiopia. A co-design workshop was held with computer scientists, epidemiological modelers, and public health partners to develop an initial list of system requirements. Subsequent updates to the system were based on feedback obtained from system evaluation workshops and assessments conducted by a steering committee of users in the public health sector. Results The system integrated epidemiological data uploaded weekly by the Amhara Regional Health Bureau with remotely-sensed environmental data freely available from online archives. Environmental data were acquired and processed automatically by the EASTWeb software program. Additional software was developed to implement a public health interface for data upload and download, harmonize the epidemiological and environmental data into a unified database, automatically update time series forecasting models, and generate formatted reports. Reporting features included district-level control charts and maps summarizing epidemiological indicators of emerging malaria outbreaks, environmental risk factors, and forecasts of future malaria risk. Conclusions Successful implementation and use of EPIDEMIA is an important step forward in the use of epidemiological and environmental informatics systems for malaria surveillance. Developing software to automate the workflow steps while remaining robust to continual changes in the input data streams was a key technical challenge. Continual stakeholder involvement throughout design, implementation, and operation has created a strong enabling environment that will facilitate the ongoing development, application, and testing of the system.
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Affiliation(s)
- Christopher L Merkord
- Geospatial Sciences Center of Excellence, South Dakota State University, Brookings, SD, USA
| | - Yi Liu
- Department of Electrical Engineering and Computer Science, South Dakota State University, Brookings, SD, USA
| | - Abere Mihretie
- Health, Development, and Anti-Malaria Association, Addis Ababa, Ethiopia
| | | | - Worku Awoke
- School of Public Health, Bahir Dar University, Bahir Dar, Ethiopia
| | - Estifanos Bayabil
- Health, Development, and Anti-Malaria Association, Addis Ababa, Ethiopia
| | - Geoffrey M Henebry
- Geospatial Sciences Center of Excellence, South Dakota State University, Brookings, SD, USA
| | | | - Mastewal Lake
- Amhara National Regional State Health Bureau, Bahir Dar, Ethiopia
| | - Michael C Wimberly
- Geospatial Sciences Center of Excellence, South Dakota State University, Brookings, SD, USA.
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