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Hilton ER, Rabeherisoa S, Ramandimbiarijaona H, Rajaratnam J, Belemvire A, Kapesa L, Zohdy S, Dentinger C, Gandaho T, Jacob D, Burnett S, Razafinjato C. Using routine health data to evaluate the impact of indoor residual spraying on malaria transmission in Madagascar. BMJ Glob Health 2023; 8:e010818. [PMID: 37463785 PMCID: PMC10357738 DOI: 10.1136/bmjgh-2022-010818] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/27/2022] [Accepted: 06/17/2023] [Indexed: 07/20/2023] Open
Abstract
INTRODUCTION Indoor residual spraying (IRS) and insecticide-treated bed nets (ITNs) are cornerstone malaria prevention methods in Madagascar. This retrospective observational study uses routine data to evaluate the impacts of IRS overall, sustained IRS exposure over multiple years and level of spray coverage (structures sprayed/found) in nine districts where non-pyrethroid IRS was deployed to complement standard pyrethroid ITNs from 2017 to 2020. METHODS Multilevel negative-binomial generalised linear models were fit to estimate the effects of IRS exposure overall, consecutive years of IRS exposure and spray coverage level on monthly all-ages population-adjusted malaria cases confirmed by rapid diagnostic test at the health facility level. The study period extended from July 2016 to June 2021. Facilities with missing data and non-geolocated communes were excluded. Facilities in IRS districts were matched with control facilities by propensity score analysis. Models were controlled for ITN survivorship, mass drug administration coverage, precipitation, enhanced vegetation index, seasonal effects and district. Predicted cases under a counterfactual no IRS scenario and number of cases averted by IRS were estimated using the fitted models. RESULTS Exposure to IRS overall reduced case incidence by an estimated 30.3% from 165.8 cases per 1000 population (95% CI=139.7 to 196.7) under a counterfactual no IRS scenario, to 114.3 (95% CI=96.5 to 135.3) over 12 months post-IRS campaign in nine districts. A third year of IRS reduced malaria cases 30.9% more than a first year (incidence rate ratio (IRR)=0.578, 95% CI=0.578 to 0.825, p<0.001) and 26.7% more than a second year (IRR=0.733, 95% CI=0.611 to 0.878, p=0.001). There was no significant difference between the first and second year (p>0.05). Coverage of 86%-90% was associated with a 19.7% reduction in incidence (IRR=0.803, 95% CI=0.690 to 0.934, p=0.005) compared with coverage ≤85%, although these results were not robust to sensitivity analysis. CONCLUSION This study demonstrates that non-pyrethroid IRS appears to substantially reduce malaria incidence in Madagascar and that sustained implementation of IRS over three years confers additional benefits.
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Affiliation(s)
| | - Saraha Rabeherisoa
- Programme National de Lutte Contre le Paludisme, Ministère de la Santé Publique, Antananarivo, Madagascar
| | - Herizo Ramandimbiarijaona
- Programme National de Lutte Contre le Paludisme, Ministère de la Santé Publique, Antananarivo, Madagascar
| | - Julie Rajaratnam
- Center for Digital and Data Excellence, PATH, Seattle, Washington, USA
| | - Allison Belemvire
- US Agency for International Development, US President's Malaria Initiative, Washington, District of Columbia, USA
| | - Laurent Kapesa
- US Agency for International Development, US President's Malaria Initiative, Antananarivo, Madagascar
| | - Sarah Zohdy
- Entomology Branch, US Centers for Disease Control and Prevention, US President's Malaria Initiative, Atlanta, Georgia, USA
| | - Catherine Dentinger
- Entomology Branch, US Centers for Disease Control and Prevention, US President's Malaria Initiative, Atlanta, Georgia, USA
| | - Timothee Gandaho
- PMI VectorLink Project, Abt Associates, Rockville, Maryland, USA
| | - Djenam Jacob
- PMI VectorLink Project, Abt Associates, Rockville, Maryland, USA
| | - Sarah Burnett
- PMI VectorLink Project, PATH, Washington, District of Columbia, USA
| | - Celestin Razafinjato
- Programme National de Lutte Contre le Paludisme, Ministère de la Santé Publique, Antananarivo, Madagascar
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Kigozi BK, Kharod GA, Bukenya H, Shadomy SV, Haberling DL, Stoddard RA, Galloway RL, Tushabe P, Nankya A, Nsibambi T, Mbidde EK, Lutwama JJ, Perniciaro JL, Nicholson WL, Bower WA, Bwogi J, Blaney DD. Investigating the etiology of acute febrile illness: a prospective clinic-based study in Uganda. BMC Infect Dis 2023; 23:411. [PMID: 37328808 PMCID: PMC10276394 DOI: 10.1186/s12879-023-08335-4] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/25/2022] [Accepted: 05/17/2023] [Indexed: 06/18/2023] Open
Abstract
BACKGROUND Historically, malaria has been the predominant cause of acute febrile illness (AFI) in sub-Saharan Africa. However, during the last two decades, malaria incidence has declined due to concerted public health control efforts, including the widespread use of rapid diagnostic tests leading to increased recognition of non-malarial AFI etiologies. Our understanding of non-malarial AFI is limited due to lack of laboratory diagnostic capacity. We aimed to determine the etiology of AFI in three distinct regions of Uganda. METHODS A prospective clinic-based study that enrolled participants from April 2011 to January 2013 using standard diagnostic tests. Participant recruitment was from St. Paul's Health Centre (HC) IV, Ndejje HC IV, and Adumi HC IV in the western, central and northern regions, which differ by climate, environment, and population density. A Pearson's chi-square test was used to evaluate categorical variables, while a two-sample t-test and Krukalis-Wallis test were used for continuous variables. RESULTS Of the 1281 participants, 450 (35.1%), 382 (29.8%), and 449 (35.1%) were recruited from the western, central, and northern regions, respectively. The median age (range) was 18 (2-93) years; 717 (56%) of the participants were female. At least one AFI pathogen was identified in 1054 (82.3%) participants; one or more non-malarial AFI pathogens were identified in 894 (69.8%) participants. The non-malarial AFI pathogens identified were chikungunya virus, 716 (55.9%); Spotted Fever Group rickettsia (SFGR), 336 (26.2%) and Typhus Group rickettsia (TGR), 97 (7.6%); typhoid fever (TF), 74 (5.8%); West Nile virus, 7 (0.5%); dengue virus, 10 (0.8%) and leptospirosis, 2 (0.2%) cases. No cases of brucellosis were identified. Malaria was diagnosed either concurrently or alone in 404 (31.5%) and 160 (12.5%) participants, respectively. In 227 (17.7%) participants, no cause of infection was identified. There were statistically significant differences in the occurrence and distribution of TF, TGR and SFGR, with TF and TGR observed more frequently in the western region (p = 0.001; p < 0.001) while SFGR in the northern region (p < 0.001). CONCLUSION Malaria, arboviral infections, and rickettsioses are major causes of AFI in Uganda. Development of a Multiplexed Point-of-Care test would help identify the etiology of non-malarial AFI in regions with high AFI rates.
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Affiliation(s)
- Brian K Kigozi
- Uganda Virus Research Institute, Entebbe, Uganda.
- College of Health Sciences, Clinical Epidemiology Unit, Makerere University, Kampala, Uganda.
| | - Grishma A Kharod
- CDC Division of High-Consequence Pathogens and Pathology, Atlanta, USA
| | | | - Sean V Shadomy
- CDC Division of High-Consequence Pathogens and Pathology, Atlanta, USA
| | - Dana L Haberling
- CDC Division of High-Consequence Pathogens and Pathology, Atlanta, USA
| | - Robyn A Stoddard
- CDC Division of High-Consequence Pathogens and Pathology, Atlanta, USA
| | - Renee L Galloway
- CDC Division of High-Consequence Pathogens and Pathology, Atlanta, USA
| | | | - Annet Nankya
- Uganda Virus Research Institute, Entebbe, Uganda
| | - Thomas Nsibambi
- Uganda Virus Research Institute, Entebbe, Uganda
- US Centers for Disease Control and Prevention, Kampala, Uganda
| | | | | | | | | | - William A Bower
- CDC Division of High-Consequence Pathogens and Pathology, Atlanta, USA
| | | | - David D Blaney
- CDC Division of High-Consequence Pathogens and Pathology, Atlanta, USA
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Whittaker C, Hamlet A, Sherrard-Smith E, Winskill P, Cuomo-Dannenburg G, Walker PGT, Sinka M, Pironon S, Kumar A, Ghani A, Bhatt S, Churcher TS. Seasonal dynamics of Anopheles stephensi and its implications for mosquito detection and emergent malaria control in the Horn of Africa. Proc Natl Acad Sci U S A 2023; 120:e2216142120. [PMID: 36791102 PMCID: PMC9974477 DOI: 10.1073/pnas.2216142120] [Citation(s) in RCA: 10] [Impact Index Per Article: 10.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/27/2022] [Accepted: 01/20/2023] [Indexed: 02/16/2023] Open
Abstract
Invasion of the malaria vector Anopheles stephensi across the Horn of Africa threatens control efforts across the continent, particularly in urban settings where the vector is able to proliferate. Malaria transmission is primarily determined by the abundance of dominant vectors, which often varies seasonally with rainfall. However, it remains unclear how An. stephensi abundance changes throughout the year, despite this being a crucial input to surveillance and control activities. We collate longitudinal catch data from across its endemic range to better understand the vector's seasonal dynamics and explore the implications of this seasonality for malaria surveillance and control across the Horn of Africa. Our analyses reveal pronounced variation in seasonal dynamics, the timing and nature of which are poorly predicted by rainfall patterns. Instead, they are associated with temperature and patterns of land use; frequently differing between rural and urban settings. Our results show that timing entomological surveys to coincide with rainy periods is unlikely to improve the likelihood of detecting An. stephensi. Integrating these results into a malaria transmission model, we show that timing indoor residual spraying campaigns to coincide with peak rainfall offers little improvement in reducing disease burden compared to starting in a random month. Our results suggest that unlike other malaria vectors in Africa, rainfall may be a poor guide to predicting the timing of peaks in An. stephensi-driven malaria transmission. This highlights the urgent need for longitudinal entomological monitoring of the vector in its new environments given recent invasion and potential spread across the continent.
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Affiliation(s)
- Charles Whittaker
- Medical Research Council Centre for Global Infectious Disease Analysis, School of Public Health, Imperial College London, LondonW2 1PG, UK
| | - Arran Hamlet
- Medical Research Council Centre for Global Infectious Disease Analysis, School of Public Health, Imperial College London, LondonW2 1PG, UK
| | - Ellie Sherrard-Smith
- Medical Research Council Centre for Global Infectious Disease Analysis, School of Public Health, Imperial College London, LondonW2 1PG, UK
| | - Peter Winskill
- Medical Research Council Centre for Global Infectious Disease Analysis, School of Public Health, Imperial College London, LondonW2 1PG, UK
| | - Gina Cuomo-Dannenburg
- Medical Research Council Centre for Global Infectious Disease Analysis, School of Public Health, Imperial College London, LondonW2 1PG, UK
| | - Patrick G. T. Walker
- Medical Research Council Centre for Global Infectious Disease Analysis, School of Public Health, Imperial College London, LondonW2 1PG, UK
| | - Marianne Sinka
- Department of Biology, University of Oxford, OxfordOX1 3SZ, UK
| | - Samuel Pironon
- Royal Botanic Gardens Kew, Richmond, SurreyTW9 3AQ, UK
- United Nations Environment Program World Conservation Monitoring Centre, CambridgeCB3 0DL, UK
| | - Ashwani Kumar
- Vector Control Research Centre, Puducherry605006, India
| | - Azra Ghani
- Medical Research Council Centre for Global Infectious Disease Analysis, School of Public Health, Imperial College London, LondonW2 1PG, UK
| | - Samir Bhatt
- Medical Research Council Centre for Global Infectious Disease Analysis, School of Public Health, Imperial College London, LondonW2 1PG, UK
- Section of Epidemiology, Department of Public Health, University of Copenhagen, Copenhagen1353, Denmark
| | - Thomas S. Churcher
- Medical Research Council Centre for Global Infectious Disease Analysis, School of Public Health, Imperial College London, LondonW2 1PG, UK
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Zhou Y, Zhang WX, Tembo E, Xie MZ, Zhang SS, Wang XR, Wei TT, Feng X, Zhang YL, Du J, Liu YQ, Zhang X, Cui F, Lu QB. Effectiveness of indoor residual spraying on malaria control: a systematic review and meta-analysis. Infect Dis Poverty 2022; 11:83. [PMID: 35870946 PMCID: PMC9308352 DOI: 10.1186/s40249-022-01005-8] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/12/2022] [Accepted: 06/30/2022] [Indexed: 11/18/2022] Open
Abstract
Background Indoor residual spraying (IRS) is one of the key interventions recommended by World Health Organization in preventing malaria infection. We aimed to conduct a systematic review and meta-analysis of global studies about the impact of IRS on malaria control. Method We searched PubMed, Web of Science, Embase, and Scopus for relevant studies published from database establishment to 31 December 2021. Random-effects models were used to perform meta-analysis and subgroup analysis to pool the odds ratio (OR) and 95% confidence interval (CI). Meta-regression was used to investigate potential factors of heterogeneity across studies. Results Thirty-eight articles including 81 reports and 1,174,970 individuals were included in the meta-analysis. IRS was associated with lower rates of malaria infection (OR = 0.35, 95% CI: 0.27–0.44). The significantly higher effectiveness was observed in IRS coverage ≥ 80% than in IRS coverage < 80%. Pyrethroids was identified to show the greatest performance in malaria control. In addition, higher effectiveness was associated with a lower gross domestic product
as well as a higher coverage of IRS and bed net utilization. Conclusions IRS could induce a positive effect on malaria infection globally. The high IRS coverage and the use of pyrethroids are key measures to reduce malaria infection. More efforts should focus on increasing IRS coverage, developing more effective new insecticides against malaria, and using multiple interventions comprehensively to achieve malaria control goals. Supplementary Information The online version contains supplementary material available at 10.1186/s40249-022-01005-8.
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Omondi CJ, Otambo WO, Odongo D, Ochwedo KO, Otieno A, Onyango SA, Orondo P, Ondeto BM, Lee MC, Zhong D, Kazura JW, Githeko AK, Yan G. Asymptomatic and submicroscopic Plasmodium infections in an area before and during integrated vector control in Homa Bay, western Kenya. Malar J 2022; 21:272. [PMID: 36153552 PMCID: PMC9509636 DOI: 10.1186/s12936-022-04288-2] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/24/2021] [Accepted: 09/08/2022] [Indexed: 11/10/2022] Open
Abstract
BACKGROUND Long-lasting insecticidal nets (LLINs) have been the primary vector control strategy until indoor residual spraying (IRS) was added in Homa Bay and Migori Counties in western Kenya. The objective of this study was to evaluate the impact of LLINs integrated with IRS on the prevalence of asymptomatic and submicroscopic Plasmodium infections in Homa Bay County. METHODS A two-stage cluster sampling procedure was employed to enroll study participants aged ≥ 6 months old. Four consecutive community cross-sectional surveys for Plasmodium infection were conducted in residents of Homa Bay county, Kenya. Prior to the start of the study, all study households received LLINs, which were distributed between June 2017 and March 2018. The first (February 2018) and second (June 2018) surveys were conducted before and after the first round of IRS (Feb-Mar 2018), while the third (February 2019) and fourth (June 2019) surveys were conducted before and after the second application of IRS (February-March 2019). Finger-prick blood samples were obtained to prepare thick and thin smears for microscopic determination and qPCR diagnosis of Plasmodium genus. RESULTS Plasmodium spp. infection prevalence by microscopy was 18.5% (113/610) before IRS, 14.2% (105/737) and 3.3% (24/720) after the first round of IRS and 1.3% (11/849) after the second round of IRS (p < 0.0001). Submicroscopic (blood smear negative, qPCR positive) parasitaemia reduced from 18.9% (115/610) before IRS to 5.4% (46/849) after IRS (p < 0.0001). However, the proportion of PCR positive infections that were submicroscopic increased from 50.4% (115/228) to 80.7% (46/57) over the study period (p < 0.0001). Similarly, while the absolute number and proportions of microscopy positives which were asymptomatic decreased from 12% (73/610) to 1.2% (9/849) (p < 0.0001), the relative proportion increased. Geometric mean density of P. falciparum parasitaemia decreased over the 2-year study period (p < 0.0001). CONCLUSIONS These data suggest that two annual rounds of IRS integrated with LLINs significantly reduced the prevalence of Plasmodium parasitaemia, while the proportion of asymptomatic and submicroscopic infections increased. To reduce cryptic P. falciparum transmission and improve malaria control, strategies aimed at reducing the number of asymptomatic and submicroscopic infections should be considered.
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Affiliation(s)
- Collince J Omondi
- Department of Biology, Faculty of Science and Technology, University of Nairobi, Nairobi, Kenya.
- Sub-Saharan International Center of Excellence for Malaria Research, Homa Bay, Kenya.
| | - Wilfred O Otambo
- Sub-Saharan International Center of Excellence for Malaria Research, Homa Bay, Kenya
- Department of Zoology, Maseno University, Kisumu, Kenya
| | - David Odongo
- Department of Biology, Faculty of Science and Technology, University of Nairobi, Nairobi, Kenya
| | - Kevin O Ochwedo
- Department of Biology, Faculty of Science and Technology, University of Nairobi, Nairobi, Kenya
- Sub-Saharan International Center of Excellence for Malaria Research, Homa Bay, Kenya
| | - Antony Otieno
- Department of Biology, Faculty of Science and Technology, University of Nairobi, Nairobi, Kenya
| | - Shirley A Onyango
- Sub-Saharan International Center of Excellence for Malaria Research, Homa Bay, Kenya
- Department of Zoological Sciences, School of Science and Technology, Kenyatta University, Nairobi, Kenya
| | - Pauline Orondo
- Sub-Saharan International Center of Excellence for Malaria Research, Homa Bay, Kenya
| | - Benyl M Ondeto
- Department of Biology, Faculty of Science and Technology, University of Nairobi, Nairobi, Kenya
- Sub-Saharan International Center of Excellence for Malaria Research, Homa Bay, Kenya
| | - Ming-Chieh Lee
- Sub-Saharan International Center of Excellence for Malaria Research, Homa Bay, Kenya
- Program in Public Health, College of Health Sciences, University of California, Irvine, CA, 92697, USA
| | - Daibin Zhong
- Program in Public Health, College of Health Sciences, University of California, Irvine, CA, 92697, USA
| | - James W Kazura
- Center for Global Health and Diseases, Case Western Reserve University, Cleveland, OH, 44106, USA
| | - Andrew K Githeko
- Sub-Saharan International Center of Excellence for Malaria Research, Homa Bay, Kenya
- Climate and Human Health Research Unit, Center for Global Health Research, Kenya Medical Research Institute, Kisumu, Kenya
| | - Guiyun Yan
- Program in Public Health, College of Health Sciences, University of California, Irvine, CA, 92697, USA
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Birungi K, Mabuka DP, Balyesima V, Namukwaya A, Chemoges EW, Kiwuwa-Muyingo S, Collins CM, Tripet F, Kayondo JK. Eave and swarm collections prove effective for biased captures of male Anopheles gambiae mosquitoes in Uganda. Parasit Vectors 2021; 14:281. [PMID: 34039430 PMCID: PMC8152359 DOI: 10.1186/s13071-021-04770-x] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/15/2021] [Accepted: 05/03/2021] [Indexed: 11/20/2022] Open
Abstract
BACKGROUND Traditional malaria vector sampling techniques bias collections towards female mosquitoes. Comprehensive understanding of vector dynamics requires balanced vector sampling of both males and females. Male mosquito sampling is also necessary for population size estimations by male-based mark-release-recapture (MRR) studies and for developing innovations in mosquito control, such as the male-targeted sterile insect technique and other genetic modification approaches. This study evaluated a range of collection methods which show promise in providing a more equal, or even male-biased, sex representation in the sample. RESULTS Swarms were found at all study sites and were more abundant and larger at the peak of the wet season. Swarm sampling caught the most males, but when man/hour effort was factored in, sampling of eaves by aspiration was the more efficient method and also provided a representative sample of females. Grass-roofed houses were the most productive for eave collections. Overall few mosquitoes were caught with artificial resting traps (clay pots and buckets), although these sampling methods performed better at the start of the wet season than at its peak, possibly because of changes in mosquito ecology and an increased availability of natural resting sites later in the season. Aspiration of bushes was more productive at the peak of the wet season than at the start. CONCLUSIONS The results of this study demonstrate that eave aspiration was an efficient and useful male mosquito collection method at the study sites and a potentially powerful aid for swarm location and MRR studies. The methods evaluated may together deliver more sex-balanced mosquito captures and can be used in various combinations depending on the aims and ecological parameters of a given study.
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Affiliation(s)
- Krystal Birungi
- Entomology Division, Uganda Virus Research Institute (UVRI), Plot 51-59, P.O. Box 49, Entebbe, Uganda
| | - Danspaid P. Mabuka
- Entomology Division, Uganda Virus Research Institute (UVRI), Plot 51-59, P.O. Box 49, Entebbe, Uganda
| | - Victor Balyesima
- Entomology Division, Uganda Virus Research Institute (UVRI), Plot 51-59, P.O. Box 49, Entebbe, Uganda
| | - Annet Namukwaya
- Entomology Division, Uganda Virus Research Institute (UVRI), Plot 51-59, P.O. Box 49, Entebbe, Uganda
| | - Elinor W. Chemoges
- Entomology Division, Uganda Virus Research Institute (UVRI), Plot 51-59, P.O. Box 49, Entebbe, Uganda
| | | | - C. Matilda Collins
- The Centre for Environmental Policy, Imperial College London, The Weeks Building, 16-18 Princes Gardens, London, SW7 1NE UK
| | - Frederic Tripet
- Centre for Applied Entomology and Parasitology, School of Life Sciences, Keele University, Staffordshire, ST5 5BG UK
| | - Jonathan K. Kayondo
- Entomology Division, Uganda Virus Research Institute (UVRI), Plot 51-59, P.O. Box 49, Entebbe, Uganda
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Okiring J, Epstein A, Namuganga JF, Kamya V, Sserwanga A, Kapisi J, Ebong C, Kigozi SP, Mpimbaza A, Wanzira H, Briggs J, Kamya MR, Nankabirwa JI, Dorsey G. Relationships between test positivity rate, total laboratory confirmed cases of malaria, and malaria incidence in high burden settings of Uganda: an ecological analysis. Malar J 2021; 20:42. [PMID: 33441121 PMCID: PMC7805073 DOI: 10.1186/s12936-021-03584-7] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/24/2020] [Accepted: 01/07/2021] [Indexed: 01/23/2023] Open
Abstract
BACKGROUND Malaria surveillance is critical for monitoring changes in malaria morbidity over time. National Malaria Control Programmes often rely on surrogate measures of malaria incidence, including the test positivity rate (TPR) and total laboratory confirmed cases of malaria (TCM), to monitor trends in malaria morbidity. However, there are limited data on the accuracy of TPR and TCM for predicting temporal changes in malaria incidence, especially in high burden settings. METHODS This study leveraged data from 5 malaria reference centres (MRCs) located in high burden settings over a 15-month period from November 2018 through January 2020 as part of an enhanced health facility-based surveillance system established in Uganda. Individual level data were collected from all outpatients including demographics, laboratory test results, and village of residence. Estimates of malaria incidence were derived from catchment areas around the MRCs. Temporal relationships between monthly aggregate measures of TPR and TCM relative to estimates of malaria incidence were examined using linear and exponential regression models. RESULTS A total of 149,739 outpatient visits to the 5 MRCs were recorded. Overall, malaria was suspected in 73.4% of visits, 99.1% of patients with suspected malaria received a diagnostic test, and 69.7% of those tested for malaria were positive. Temporal correlations between monthly measures of TPR and malaria incidence using linear and exponential regression models were relatively poor, with small changes in TPR frequently associated with large changes in malaria incidence. Linear regression models of temporal changes in TCM provided the most parsimonious and accurate predictor of changes in malaria incidence, with adjusted R2 values ranging from 0.81 to 0.98 across the 5 MRCs. However, the slope of the regression lines indicating the change in malaria incidence per unit change in TCM varied from 0.57 to 2.13 across the 5 MRCs, and when combining data across all 5 sites, the R2 value reduced to 0.38. CONCLUSIONS In high malaria burden areas of Uganda, site-specific temporal changes in TCM had a strong linear relationship with malaria incidence and were a more useful metric than TPR. However, caution should be taken when comparing changes in TCM across sites.
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Affiliation(s)
- Jaffer Okiring
- Clinical Epidemiology Unit, School of Medicine, Makerere University College of Health Sciences, Kampala, Uganda.
| | - Adrienne Epstein
- Department of Epidemiology and Biostatistics, University of California, San Francisco, USA
| | - Jane F Namuganga
- Infectious Diseases Research Collaboration, 2C Nakasero Hill Road, Kampala, Uganda
| | - Victor Kamya
- Infectious Diseases Research Collaboration, 2C Nakasero Hill Road, Kampala, Uganda
| | - Asadu Sserwanga
- Infectious Diseases Research Collaboration, 2C Nakasero Hill Road, Kampala, Uganda
| | - James Kapisi
- Infectious Diseases Research Collaboration, 2C Nakasero Hill Road, Kampala, Uganda
| | - Chris Ebong
- Infectious Diseases Research Collaboration, 2C Nakasero Hill Road, Kampala, Uganda
| | - Simon P Kigozi
- Infectious Diseases Research Collaboration, 2C Nakasero Hill Road, Kampala, Uganda
| | - Arthur Mpimbaza
- Infectious Diseases Research Collaboration, 2C Nakasero Hill Road, Kampala, Uganda
| | | | - Jessica Briggs
- Department of Medicine, University of California, San Francisco, USA
| | - Moses R Kamya
- Clinical Epidemiology Unit, School of Medicine, Makerere University College of Health Sciences, Kampala, Uganda
| | - Joaniter I Nankabirwa
- Clinical Epidemiology Unit, School of Medicine, Makerere University College of Health Sciences, Kampala, Uganda
| | - Grant Dorsey
- Department of Medicine, University of California, San Francisco, USA
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Kigozi SP, Kigozi RN, Sebuguzi CM, Cano J, Rutazaana D, Opigo J, Bousema T, Yeka A, Gasasira A, Sartorius B, Pullan RL. Spatial-temporal patterns of malaria incidence in Uganda using HMIS data from 2015 to 2019. BMC Public Health 2020; 20:1913. [PMID: 33317487 PMCID: PMC7737387 DOI: 10.1186/s12889-020-10007-w] [Citation(s) in RCA: 22] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/07/2020] [Accepted: 12/04/2020] [Indexed: 11/21/2022] Open
Abstract
BACKGROUND As global progress to reduce malaria transmission continues, it is increasingly important to track changes in malaria incidence rather than prevalence. Risk estimates for Africa have largely underutilized available health management information systems (HMIS) data to monitor trends. This study uses national HMIS data, together with environmental and geographical data, to assess spatial-temporal patterns of malaria incidence at facility catchment level in Uganda, over a recent 5-year period. METHODS Data reported by 3446 health facilities in Uganda, between July 2015 and September 2019, was analysed. To assess the geographic accessibility of the health facilities network, AccessMod was employed to determine a three-hour cost-distance catchment around each facility. Using confirmed malaria cases and total catchment population by facility, an ecological Bayesian conditional autoregressive spatial-temporal Poisson model was fitted to generate monthly posterior incidence rate estimates, adjusted for caregiver education, rainfall, land surface temperature, night-time light (an indicator of urbanicity), and vegetation index. RESULTS An estimated 38.8 million (95% Credible Interval [CI]: 37.9-40.9) confirmed cases of malaria occurred over the period, with a national mean monthly incidence rate of 20.4 (95% CI: 19.9-21.5) cases per 1000, ranging from 8.9 (95% CI: 8.7-9.4) to 36.6 (95% CI: 35.7-38.5) across the study period. Strong seasonality was observed, with June-July experiencing highest peaks and February-March the lowest peaks. There was also considerable geographic heterogeneity in incidence, with health facility catchment relative risk during peak transmission months ranging from 0 to 50.5 (95% CI: 49.0-50.8) times higher than national average. Both districts and health facility catchments showed significant positive spatial autocorrelation; health facility catchments had global Moran's I = 0.3 (p < 0.001) and districts Moran's I = 0.4 (p < 0.001). Notably, significant clusters of high-risk health facility catchments were concentrated in Acholi, West Nile, Karamoja, and East Central - Busoga regions. CONCLUSION Findings showed clear countrywide spatial-temporal patterns with clustering of malaria risk across districts and health facility catchments within high risk regions, which can facilitate targeting of interventions to those areas at highest risk. Moreover, despite high and perennial transmission, seasonality for malaria incidence highlights the potential for optimal and timely implementation of targeted interventions.
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Affiliation(s)
- Simon P Kigozi
- Department of Disease Control, London School of Hygiene & Tropical Medicine, Keppel Street, London, WC1E 7HT, UK. .,Infectious Diseases Research Collaboration, PO Box 7475, Kampala, Uganda.
| | - Ruth N Kigozi
- USAID's Malaria Action Program for Districts, PO Box 8045, Kampala, Uganda
| | - Catherine M Sebuguzi
- Infectious Diseases Research Collaboration, PO Box 7475, Kampala, Uganda.,National Malaria Control Division, Uganda Ministry of Health, Kampala, Uganda
| | - Jorge Cano
- Department of Disease Control, London School of Hygiene & Tropical Medicine, Keppel Street, London, WC1E 7HT, UK
| | - Damian Rutazaana
- National Malaria Control Division, Uganda Ministry of Health, Kampala, Uganda
| | - Jimmy Opigo
- National Malaria Control Division, Uganda Ministry of Health, Kampala, Uganda
| | - Teun Bousema
- Department of Medical Microbiology, Radboud University, Nijmegen, Netherlands
| | - Adoke Yeka
- Department of Disease Control and Environmental Health, College of Health Sciences, School of Public Health, Makerere University, PO Box 7072, Kampala, Uganda
| | - Anne Gasasira
- African Leaders Malaria Alliance (ALMA), Kampala, Uganda
| | - Benn Sartorius
- Department of Disease Control, London School of Hygiene & Tropical Medicine, Keppel Street, London, WC1E 7HT, UK
| | - Rachel L Pullan
- Department of Disease Control, London School of Hygiene & Tropical Medicine, Keppel Street, London, WC1E 7HT, UK
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9
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Mpimbaza A, Sserwanga A, Rutazaana D, Kapisi J, Walemwa R, Suiyanka L, Kyalo D, Kamya M, Opigo J, Snow RW. Changing malaria fever test positivity among paediatric admissions to Tororo district hospital, Uganda 2012-2019. Malar J 2020; 19:416. [PMID: 33213469 PMCID: PMC7678291 DOI: 10.1186/s12936-020-03490-4] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/21/2020] [Accepted: 11/09/2020] [Indexed: 12/14/2022] Open
Abstract
BACKGROUND The World Health Organization (WHO) promotes long-lasting insecticidal nets (LLIN) and indoor residual house-spraying (IRS) for malaria control in endemic countries. However, long-term impact data of vector control interventions is rarely measured empirically. METHODS Surveillance data was collected from paediatric admissions at Tororo district hospital for the period January 2012 to December 2019, during which LLIN and IRS campaigns were implemented in the district. Malaria test positivity rate (TPR) among febrile admissions aged 1 month to 14 years was aggregated at baseline and three intervention periods (first LLIN campaign; Bendiocarb IRS; and Actellic IRS + second LLIN campaign) and compared using before-and-after analysis. Interrupted time-series analysis (ITSA) was used to determine the effect of IRS (Bendiocarb + Actellic) with the second LLIN campaign on monthly TPR compared to the combined baseline and first LLIN campaign periods controlling for age, rainfall, type of malaria test performed. The mean and median ages were examined between intervention intervals and as trend since January 2012. RESULTS Among 28,049 febrile admissions between January 2012 and December 2019, TPR decreased from 60% at baseline (January 2012-October 2013) to 31% during the final period of Actellic IRS and LLIN (June 2016-December 2019). Comparing intervention intervals to the baseline TPR (60.3%), TPR was higher during the first LLIN period (67.3%, difference 7.0%; 95% CI 5.2%, 8.8%, p < 0.001), and lower during the Bendiocarb IRS (43.5%, difference - 16.8%; 95% CI - 18.7%, - 14.9%) and Actellic IRS (31.3%, difference - 29.0%; 95% CI - 30.3%, - 27.6%, p < 0.001) periods. ITSA confirmed a significant decrease in the level and trend of TPR during the IRS (Bendicarb + Actellic) with the second LLIN period compared to the pre-IRS (baseline + first LLIN) period. The age of children with positive test results significantly increased with time from a mean of 24 months at baseline to 39 months during the final IRS and LLIN period. CONCLUSION IRS can have a dramatic impact on hospital paediatric admissions harbouring malaria infection. The sustained expansion of effective vector control leads to an increase in the age of malaria positive febrile paediatric admissions. However, despite large reductions, malaria test-positive admissions continued to be concentrated in children aged under five years. Despite high coverage of IRS and LLIN, these vector control measures failed to interrupt transmission in Tororo district. Using simple, cost-effective hospital surveillance, it is possible to monitor the public health impacts of IRS in combination with LLIN.
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Affiliation(s)
- Arthur Mpimbaza
- Child Health and Development Centre, Makerere University, College of Health Sciences, Kampala, Uganda.
- Infectious Diseases Research Collaboration, Kampala, Uganda.
| | | | - Damian Rutazaana
- National Malaria Control Division, Ministry of Health, Kampala, Uganda
| | - James Kapisi
- Infectious Diseases Research Collaboration, Kampala, Uganda
| | - Richard Walemwa
- Department of Prevention, Care and Treatment, Infectious Diseases Institute, Kampala, Uganda
| | - Laurissa Suiyanka
- Population Health Unit, Kenya Medical Research Institute/Wellcome Trust Research Programme, Nairobi, Kenya
| | - David Kyalo
- Population Health Unit, Kenya Medical Research Institute/Wellcome Trust Research Programme, Nairobi, Kenya
| | - Moses Kamya
- Infectious Diseases Research Collaboration, Kampala, Uganda
| | - Jimmy Opigo
- National Malaria Control Division, Ministry of Health, Kampala, Uganda
| | - Robert W Snow
- Population Health Unit, Kenya Medical Research Institute/Wellcome Trust Research Programme, Nairobi, Kenya
- Centre for Tropical Medicine and Global Health, Nuffield Department of Medicine, University of Oxford, Oxford, UK
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10
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Estimating the optimal interval between rounds of indoor residual spraying of insecticide using malaria incidence data from cohort studies. PLoS One 2020; 15:e0241033. [PMID: 33095812 PMCID: PMC7584202 DOI: 10.1371/journal.pone.0241033] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/14/2020] [Accepted: 10/07/2020] [Indexed: 12/05/2022] Open
Abstract
Background Indoor residual spraying (IRS) reduces vector densities and malaria transmission, however, the most effective spraying intervals for IRS have not been well established. We estimated the optimal timing interval for IRS using a statistical approach. Methods Six rounds of IRS were implemented in Tororo District, a historically high malaria transmission setting in Uganda, during the study period (3 rounds with bendiocarb active ingredient (Ficam®): December 2014 to December 2015, and 3 rounds with pirimiphos methyl active ingredient (Actellic 300®CS): June 2016 to July 2018). A generalized additive model was used to estimate the optimal timing interval for IRS based on the predicted malaria incidence. The model was fitted to clinical incidence data from a cohort of children aged 0.5–10 years from selected households observed throughout the study period. Results 494 children, 67% aged less than 5 years at enrolment were analysed. Six-months period incidence of malaria decreased from 2.96 per person-years at the baseline to 1.74 following the first round of IRS and then to 0.02 after 6 rounds of IRS. The optimal time interval for IRS differed between bendiocarb and pirimiphos methyl and by IRS round. To retain an optimum impact, bendiocarb would require respraying 17 (95% CI: 14.2–21.0) weeks after application whereas pirimiphos methyl could remain impactful for 40 (95% CI: 37.0–42.8) weeks, although in the final year this estimates 36 (95% CI: 32.7–37.7) weeks. However, we could not estimate from the data the optimal time after the second and third rounds of bendiocarb and after the second round of pirimiphos methyl. Neither the amount of rainfall nor the EIR nor the distribution of nets were found to be statistically significant for determining the time period between spray rounds. Conclusion In our setting, the effect of the two IRS products was distinct. Statistically, pirimiphos methyl provided a longer window of protection than bendiocarb, although impact varied between different spray rounds and years which was not explained by rainfall or EIR or distribution of nets in our statistical approach. Understanding the effectiveness of IRS and how long it lasts can help for planning campaigns, but one should consider the financial cost and insecticide resistance. Monitoring the timing of spray campaigns using clinical incidence could be repeated in future programs to help determine the average period of protectivity of these products.
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11
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Kamau A, Mtanje G, Mataza C, Malla L, Bejon P, Snow RW. The relationship between facility-based malaria test positivity rate and community-based parasite prevalence. PLoS One 2020; 15:e0240058. [PMID: 33027313 PMCID: PMC7540858 DOI: 10.1371/journal.pone.0240058] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/08/2020] [Accepted: 09/17/2020] [Indexed: 02/06/2023] Open
Abstract
INTRODUCTION Malaria surveillance is a key pillar in the control of malaria in Africa. The value of using routinely collected data from health facilities to define malaria risk at community levels remains poorly defined. METHODS Four cross-sectional parasite prevalence surveys were undertaken among residents at 36 enumeration zones in Kilifi county on the Kenyan coast and temporally and spatially matched to fever surveillance at 6 health facilities serving the same communities over 12 months. The age-structured functional form of the relationship between test positivity rate (TPR) and community-based parasite prevalence (PR) was explored through the development of regression models fitted by alternating the linear, exponential and polynomial terms for PR. The predictive ranges of TPR were explored for PR endemicity risk groups of control programmatic value using cut-offs of low (PR <5%) and high (PR ≥ 30%) transmission intensity. RESULTS Among 28,134 febrile patients encountered for malaria diagnostic testing in the health facilities, 12,143 (43.2%: 95% CI: 42.6%, 43.7%) were positive. The overall community PR was 9.9% (95% CI: 9.2%, 10.7%) among 6,479 participants tested for malaria. The polynomial model was the best fitting model for the data that described the algebraic relationship between TPR and PR. In this setting, a TPR of ≥ 49% in all age groups corresponded to an age-standardized PR of ≥ 30%, while a TPR of < 40% corresponded to an age-standardized PR of < 5%. CONCLUSION A non-linear relationship was observed between the relative change in TPR and changes in the PR, which is likely to have important implications for malaria surveillance programs, especially at the extremes of transmission. However, larger, more spatially diverse data series using routinely collected TPR data matched to community-based infection prevalence data are required to explore the more practical implications of using TPR as a replacement for community PR.
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Affiliation(s)
- Alice Kamau
- KEMRI-Wellcome Trust Research Programme, Kilifi, Kenya
- Centre for Tropical Medicine and Global Health, Nuffield Department of Clinical Medicine, University of Oxford, Oxford, United Kingdom
- * E-mail:
| | - Grace Mtanje
- KEMRI-Wellcome Trust Research Programme, Kilifi, Kenya
| | - Christine Mataza
- KEMRI-Wellcome Trust Research Programme, Kilifi, Kenya
- Ministry of Health, Kilifi County Government, Kilifi, Kenya
| | - Lucas Malla
- KEMRI-Wellcome Trust Research Programme, Kilifi, Kenya
| | - Philip Bejon
- KEMRI-Wellcome Trust Research Programme, Kilifi, Kenya
- Centre for Tropical Medicine and Global Health, Nuffield Department of Clinical Medicine, University of Oxford, Oxford, United Kingdom
| | - Robert W. Snow
- KEMRI-Wellcome Trust Research Programme, Kilifi, Kenya
- Centre for Tropical Medicine and Global Health, Nuffield Department of Clinical Medicine, University of Oxford, Oxford, United Kingdom
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12
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Kané F, Keïta M, Traoré B, Diawara SI, Bane S, Diarra S, Sogoba N, Doumbia S. Performance of IRS on malaria prevalence and incidence using pirimiphos-methyl in the context of pyrethroid resistance in Koulikoro region, Mali. Malar J 2020; 19:286. [PMID: 32787938 PMCID: PMC7425591 DOI: 10.1186/s12936-020-03357-8] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/15/2020] [Accepted: 08/03/2020] [Indexed: 11/10/2022] Open
Abstract
Background Koulikoro Health District is one of three districts of Mali where the indoor residual spray (IRS) has been implemented from 2008 to 2016. With widespread of resistance to pyrethroid, IRS was shifted from pyrethroid to pirimiphos-methyl from 2014 to 2016. The objective of this study was to assess the added value of IRS to LLINs on the prevalence of parasitaemia and malaria incidence among children under 10 years old. Methods A comparative study was carried out to assess the effects of pirimiphos-methyl based IRS on malaria prevalence and incidence among children from 6 months to 10 years old in selected pyrethroid resistance villages of two health districts in Mali: one where IRS was implemented in combination with LLINs (intervention area) and one with LLINs-only (control area). Two cross-sectional surveys were carried out at the beginning (June) and end of the rainy season (October) to assess seasonal changes in malaria parasitaemia by microscopy. A passive detection case (PCD) was set-up in each study village for 9 months to estimate the incidence of malaria using RDT. Results There was an increase of 220% in malaria prevalence from June to October in the control area (14% to 42%) versus only 53% in the IRS area (9.2% to 13.2%). Thus, the proportional rise in malaria prevalence from the dry to the rainy season in 2016 was 4-times greater in the control area compared to the IRS area. The overall malaria incidence rate was 2.7 per 100 person-months in the IRS area compared with 6.8 per 100 person-month in the control areas. The Log-rank test of Kaplan–Meier survival analysis showed that children living in IRS area remain much longer free from malaria (Hazard ratio (HR) = 0.45, CI 95% 0.37–0.54) than children of the control area (P < 0.0001). Conclusions IRS using pirimiphos-methyl has been successful in reducing substantially both the prevalence and the incidence of malaria in children under 10 years old in the area of pyrethroid resistance of Koulikoro, Mali. Pirimiphos-methyl is a better alternative than pyrethroids for IRS in areas with widespread of pyrethroid resistance.
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Affiliation(s)
- Fousseyni Kané
- Malaria Research and Training Centre; International Center for Excellence in Research (ICER-Mali); Faculty of Medicine and Odonto Stomatology, University of Sciences, Techniques and Technologies of Bamako (USTTB), Bamako, Mali.
| | - Moussa Keïta
- Malaria Research and Training Centre; International Center for Excellence in Research (ICER-Mali); Faculty of Medicine and Odonto Stomatology, University of Sciences, Techniques and Technologies of Bamako (USTTB), Bamako, Mali
| | - Boïssé Traoré
- Malaria Research and Training Centre; International Center for Excellence in Research (ICER-Mali); Faculty of Medicine and Odonto Stomatology, University of Sciences, Techniques and Technologies of Bamako (USTTB), Bamako, Mali
| | - Sory Ibrahim Diawara
- Malaria Research and Training Centre; International Center for Excellence in Research (ICER-Mali); Faculty of Medicine and Odonto Stomatology, University of Sciences, Techniques and Technologies of Bamako (USTTB), Bamako, Mali
| | - Sidy Bane
- Malaria Research and Training Centre; International Center for Excellence in Research (ICER-Mali); Faculty of Medicine and Odonto Stomatology, University of Sciences, Techniques and Technologies of Bamako (USTTB), Bamako, Mali
| | - Souleymane Diarra
- Malaria Research and Training Centre; International Center for Excellence in Research (ICER-Mali); Faculty of Medicine and Odonto Stomatology, University of Sciences, Techniques and Technologies of Bamako (USTTB), Bamako, Mali
| | - Nafomon Sogoba
- Malaria Research and Training Centre; International Center for Excellence in Research (ICER-Mali); Faculty of Medicine and Odonto Stomatology, University of Sciences, Techniques and Technologies of Bamako (USTTB), Bamako, Mali
| | - Seydou Doumbia
- Malaria Research and Training Centre; International Center for Excellence in Research (ICER-Mali); Faculty of Medicine and Odonto Stomatology, University of Sciences, Techniques and Technologies of Bamako (USTTB), Bamako, Mali
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13
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Echodu R, Iga J, Oyet WS, Mireji P, Anena J, Onanyang D, Iwiru T, Lutwama JJ, Opiyo EA. High insecticide resistances levels in Anopheles gambiaes s.l. in northern Uganda and its relevance for future malaria control. BMC Res Notes 2020; 13:348. [PMID: 32698844 PMCID: PMC7376877 DOI: 10.1186/s13104-020-05193-0] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/21/2020] [Accepted: 07/17/2020] [Indexed: 12/02/2022] Open
Abstract
Objective The aim of the study was to determine the level of insecticide resistance and diversity in Anopheles mosquitoes in northern Uganda. Standard WHO insecticide susceptibility test assays were used to test for susceptibility to 0.5% malathion, 0.1% bendiocarb, 0.05% deltamethrin and 0.75% permethrin on 3–5 day old generation one progeny. We also screened for species diversity and knockdown resistance using PCR assay. Results Anopheles gambiae s.s. is the predominant malaria vector in northern Uganda followed by An. arabiensis. An. gambiae s.s. was susceptible to malathion and bendiocarb with the observed mortality rate of 100% and 98–100% observed respectively while very high resistance was observed with deltamethrin and permethrin. Minimal KDR-eastern variant homozygous forms of 8.3% in An. gambiae s.s. were detected in Oyam district. In conclusion, this study confirms that An. gambiae s.s. females are susceptible to malathion and bendiocarb while high intensity of resistance was observed with deltamethrin and permethrin in the same area. Use of carbamate and organophosphate insecticides bendiocarb and malathion for indoor residual spraying activities in northern Uganda is highly recommended since high levels of pyrethroids resistance (deltamethrin and permethrin) was detected in the area.
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Affiliation(s)
- Richard Echodu
- Department of Biology, Faculty of Science, Gulu University, P.O. Box 166, Gulu, Uganda. .,Gulu University Biosciences Research Laboratories, P.O. Box 166, Gulu, Uganda.
| | - Julius Iga
- Department of Biology, Faculty of Science, Gulu University, P.O. Box 166, Gulu, Uganda
| | - William Samuel Oyet
- Department of Biology, Faculty of Science, Gulu University, P.O. Box 166, Gulu, Uganda
| | - Paul Mireji
- Department of Biochemistry, Biotechnology Research Institute-Kenya Agricultural and Livestock Research Organization, Kikuyu, Kenya
| | - Juliet Anena
- Gulu University Biosciences Research Laboratories, P.O. Box 166, Gulu, Uganda
| | - David Onanyang
- Department of Biology, Faculty of Science, Gulu University, P.O. Box 166, Gulu, Uganda
| | - Tereza Iwiru
- Gulu University Biosciences Research Laboratories, P.O. Box 166, Gulu, Uganda
| | | | - Elizabeth Auma Opiyo
- Department of Biology, Faculty of Science, Gulu University, P.O. Box 166, Gulu, Uganda
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14
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Kamau A, Mogeni P, Okiro EA, Snow RW, Bejon P. A systematic review of changing malaria disease burden in sub-Saharan Africa since 2000: comparing model predictions and empirical observations. BMC Med 2020; 18:94. [PMID: 32345315 PMCID: PMC7189714 DOI: 10.1186/s12916-020-01559-0] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/07/2020] [Accepted: 03/16/2020] [Indexed: 11/10/2022] Open
Abstract
BACKGROUND The most widely used measures of declining burden of malaria across sub-Saharan Africa are predictions from geospatial models. These models apply spatiotemporal autocorrelations and covariates to parasite prevalence data and then use a function of parasite prevalence to predict clinical malaria incidence. We attempted to assess whether trends in malaria cases, based on local surveillance, were similar to those captured by Malaria Atlas Project (MAP) incidence surfaces. METHODS We undertook a systematic review (PROSPERO International Prospective Register of Systematic Reviews; ID = CRD42019116834) to identify empirical data on clinical malaria in Africa since 2000, where reports covered at least 5 continuous years. The trends in empirical data were then compared with the trends of time-space matched clinical malaria incidence from MAP using the Spearman rank correlation. The correlations (rho) between changes in empirically observed and modelled estimates of clinical malaria were displayed by forest plots and examined by meta-regression. RESULTS Sixty-seven articles met our inclusion criteria representing 124 sites from 24 African countries. The single most important factor explaining the correlation between empirical observations and modelled predictions was the slope of empirically observed data over time (rho = - 0.989; 95% CI - 0.998, - 0.939; p < 0.001), i.e. steeper declines were associated with a stronger correlation between empirical observations and modelled predictions. Factors such as quality of study, reported measure of malaria and endemicity were only slightly predictive of such correlations. CONCLUSIONS In many locations, both local surveillance data and modelled estimates showed declines in malaria burden and hence similar trends. However, there was a weak association between individual surveillance datasets and the modelled predictions where stalling in progress or resurgence of malaria burden was empirically observed. Surveillance data were patchy, indicating a need for improved surveillance to strengthen both empiric reporting and modelled predictions.
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Affiliation(s)
- Alice Kamau
- KEMRI-Wellcome Trust Research Programme, Kilifi, Kenya. .,Centre for Tropical Medicine and Global Health, Nuffield Department of Clinical Medicine, University of Oxford, Oxford, UK.
| | | | | | - Robert W Snow
- KEMRI-Wellcome Trust Research Programme, Kilifi, Kenya.,Centre for Tropical Medicine and Global Health, Nuffield Department of Clinical Medicine, University of Oxford, Oxford, UK
| | - Philip Bejon
- KEMRI-Wellcome Trust Research Programme, Kilifi, Kenya.,Centre for Tropical Medicine and Global Health, Nuffield Department of Clinical Medicine, University of Oxford, Oxford, UK
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15
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Malaria Outbreak Facilitated by Appearance of Vector-Breeding Sites after Heavy Rainfall and Inadequate Preventive Measures: Nwoya District, Northern Uganda, February-May 2018. JOURNAL OF ENVIRONMENTAL AND PUBLIC HEALTH 2020; 2020:5802401. [PMID: 32377206 PMCID: PMC7193302 DOI: 10.1155/2020/5802401] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 10/01/2019] [Revised: 03/16/2020] [Accepted: 03/21/2020] [Indexed: 12/23/2022]
Abstract
Background Malaria is a leading cause of morbidity and mortality in Uganda. In April 2018, malaria cases surged in Nwoya District, Northern Uganda, exceeding expected limits and thereby requiring epidemic response. We investigated this outbreak to estimate its magnitude, identify exposure factors for transmission, and recommend evidence-based control measures. Methods We defined a malaria case as onset of fever in a resident of Anaka subcounty, Koch Goma subcounty, and Nwoya Town Council, Nwoya District, with a positive rapid diagnostic test or microscopy for malaria from 1 February to 25 May 2018. We reviewed medical records in all health facilities of affected subcounties to find cases. In a case-control study, we compared exposure factors between case-persons and asymptomatic controls matched by age and village. We also conducted entomological assessments on vector density and behavior. Results We identified 3,879 case-persons (attack rate [AR] = 6.5%) and two deaths (case-fatality rate = 5.2/10,000). Females (AR = 8.1%) were more affected than males (AR = 4.7%) (p < 0.0001). Of all age groups, 5–18 years (AR = 8.4%) were most affected. Heavy rain started in early March 2018, and a propagated outbreak followed in the first week of April 2018. In the case-control study, 55% (59/107) of case-persons and 18% (19/107) of controls had stagnant water around households for several days following rainfall (ORM-H = 5.6, 95% CI = 3.0–11); 25% (27/107) of case-persons and 51% (55/107) of controls wore full extremity covering clothes during evening hours (ORM-H = 0.30, 95% CI = 0.20–0.60); 71% (76/107) of case-persons and 85% (91/107) of controls slept under a long-lasting insecticide-treated net (LLIN) 14 days before symptom onset (ORM-H = 0.43, 95% CI = 0.22–0.85); 37% (40/107) of case-persons and 52% (56/107) of controls had access to at least one LLIN per 2 household members (ORM-H = 0.54, 95% CI = 0.30–0.97). Entomological assessment indicated active breeding sites in the entire study area; Anopheles gambiae sensu lato species were the predominant vector. Conclusion Increased vector-breeding sites after heavy rainfall and inadequate malaria preventive measures were found to have contributed to this outbreak. We recommended increasing coverage for LLINs and larviciding breeding sites in the area.
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16
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Sahu SS, Thankachy S, Dash S, Nallan K, Swaminathan S, Kasinathan G, Purushothaman J. Evaluation of long-lasting indoor residual spraying of deltamethrin 62.5 SC-PE against malaria vectors in India. Malar J 2020; 19:19. [PMID: 31937301 PMCID: PMC6961237 DOI: 10.1186/s12936-020-3112-4] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/15/2019] [Accepted: 01/08/2020] [Indexed: 11/10/2022] Open
Abstract
BACKGROUND Deltamethrin 62.5 polymer-enhanced suspension concentrate (SC-PE) is one of the World Health Organization-approved insecticides for indoor residual spraying and was recommended to evaluate its residual activity for determination of appropriate spray cycles in different eco-epidemiologic settings. In the current study, efficacy of deltamethrin 62.5 SC-PE was evaluated against vectors of malaria and its impact on malaria incidence in a Plasmodium falciparum hyper-endemic area in Koraput district, Odisha State, India. METHODS The trial had two comparable arms, arm 1 with residual spraying of deltamethrin 62.5 SC-PE and arm 2 with deltamethrin 2.5% WP (positive control). Comparative assessment of the impact of each intervention arm on entomological (density, parity, infection and human blood index), epidemiological (malaria incidence) parameters, residual efficacy and adverse effects were evaluated. RESULTS Both the arms were comparable in terms of entomological and epidemiological parameters. While, deltamethrin 62.5 SC-PE was found to be effective for 150 days in mud and wood surfaces and 157 days in cement surfaces; deltamethrin 2.5% was effective only for 105 days on mud surfaces and 113 days on cement and wood surfaces. CONCLUSIONS Deltamethrin 62.5 SC-PE had prolonged killing effectiveness up to 5 months. Hence, one round of IRS with deltamethrin 62.5 SC-PE would be sufficient to cover two existing malaria peak transmission seasons (July-August and October-November) in many parts of India.
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Affiliation(s)
- Sudhansu Sekhar Sahu
- Indian Council of Medical Research-Vector Control Research Centre, Puducherry, India.
| | - Sonia Thankachy
- Indian Council of Medical Research-Vector Control Research Centre, Puducherry, India
| | - Smrutidhara Dash
- Indian Council of Medical Research-Vector Control Research Centre, Puducherry, India
| | - Krishnamoorthy Nallan
- Indian Council of Medical Research-Vector Control Research Centre, Puducherry, India
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Nankabirwa JI, Briggs J, Rek J, Arinaitwe E, Nayebare P, Katrak S, Staedke SG, Rosenthal PJ, Rodriguez-Barraquer I, Kamya MR, Dorsey G, Greenhouse B. Persistent Parasitemia Despite Dramatic Reduction in Malaria Incidence After 3 Rounds of Indoor Residual Spraying in Tororo, Uganda. J Infect Dis 2020; 219:1104-1111. [PMID: 30383230 DOI: 10.1093/infdis/jiy628] [Citation(s) in RCA: 19] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/27/2018] [Accepted: 10/31/2018] [Indexed: 12/21/2022] Open
Abstract
BACKGROUND Indoor residual spraying of insecticide (IRS) has been associated with reductions in the incidence of malaria, but its impact on malaria parasitemia is unclear. METHODS We followed 469 participants from August 2011 to May 2016 in Tororo, Uganda, a historically high malaria transmission setting. Three rounds of IRS with bendiocarb were implemented from December 2014 to December 2015. Symptomatic malaria episodes were identified by passive surveillance. Parasitemia was identified by active surveillance every 1-3 months using microscopy and Plasmodium falciparum-specific loop-mediated isothermal amplification. RESULTS IRS was associated with a significant decline in the incidence of symptomatic malaria irrespective of age (episodes per person per year declined from 3.98 to 0.13 in children aged <5 years, 2.30 to 0.15 in children aged 5-10 years, and 0.41 to 0 in adults; P < .001 for all). IRS significantly reduced the prevalence of parasitemia, but the prevalence remained high (pre-IRS to post-third round: 58.5% to 11.3% in children aged <5 years, 73.3% to 23.7% in children aged 5-10 years, and 52.2% to 15.4% in adults; P < .001 for all). CONCLUSIONS Although IRS was associated with significant reductions in the incidence of malaria and prevalence of parasitemia, a proportion of the population remained parasitemic, providing a potential reservoir for malaria transmission.
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Affiliation(s)
- Joaniter I Nankabirwa
- School of Medicine, Makerere University College of Health Sciences, Kampala, Uganda.,Infectious Diseases Research Collaboration, Kampala, Uganda
| | - Jessica Briggs
- Department of Medicine, University of California, San Francisco
| | - John Rek
- Infectious Diseases Research Collaboration, Kampala, Uganda
| | | | | | - Shereen Katrak
- Department of Medicine, University of California, San Francisco
| | - Sarah G Staedke
- Department of Clinical Research, London School of Hygiene and Tropical Medicine, United Kingdom
| | | | | | - Moses R Kamya
- School of Medicine, Makerere University College of Health Sciences, Kampala, Uganda.,Infectious Diseases Research Collaboration, Kampala, Uganda
| | - Grant Dorsey
- Department of Medicine, University of California, San Francisco
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Musiime AK, Smith DL, Kilama M, Rek J, Arinaitwe E, Nankabirwa JI, Kamya MR, Conrad MD, Dorsey G, Akol AM, Staedke SG, Lindsay SW, Egonyu JP. Impact of vector control interventions on malaria transmission intensity, outdoor vector biting rates and Anopheles mosquito species composition in Tororo, Uganda. Malar J 2019; 18:445. [PMID: 31881898 PMCID: PMC6935116 DOI: 10.1186/s12936-019-3076-4] [Citation(s) in RCA: 47] [Impact Index Per Article: 9.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/23/2019] [Accepted: 12/14/2019] [Indexed: 11/10/2022] Open
Abstract
BACKGROUND Long-lasting insecticidal nets (LLINs) and indoor residual spraying of insecticide (IRS) are widely recommended for the prevention of malaria in endemic regions. Data from human landing catches provide information on the impact of vector control on vector populations. Here, malaria transmission indoors and outdoors, before and after mass deployment of LLINs and IRS in Uganda was compared. METHODS The study took place in Tororo district, a historically high transmission area where universal LLIN distribution was conducted in November 2013 and May 2017 and 6 rounds of IRS implemented from December 2014 to July 2018. Human landing catches were performed in 8 houses monthly from October 2011 to September 2012 (pre-intervention period) and every 4 weeks from November 2017 to October 2018 (post-intervention period). Mosquitoes were collected outdoors from 18:00 to 22:00 h and indoors from 18:00 to 06:00 h. Female Anopheles were tested for the presence of Plasmodium falciparum sporozoites and species identification performed using gross dissection and polymerase chain reaction (PCR). RESULTS The interventions were associated with a decline in human biting rate from 19.6 to 2.3 female Anopheles mosquitoes per house per night (p < 0.001) and annual entomological inoculation rate from 129 to 0 infective bites per person per year (p < 0.001). The proportion of mosquitoes collected outdoors increased from 11.6 to 49.4% (p < 0.001). Prior to the interventions the predominant species was Anopheles gambiae sensu stricto (s.s.), which comprised an estimated 76.7% of mosquitoes. Following the interventions, the predominant species was Anopheles arabiensis, which comprised 99.5% of mosquitoes, with almost complete elimination of An. gambiae s.s. (0.5%). CONCLUSIONS Mass distribution of LLINs and 6 rounds of IRS dramatically decreased vector density and sporozoite rate resulting in a marked reduction in malaria transmission intensity in a historically high transmission site in Uganda. These changes were accompanied by a shift in vector species from An. gambiae s.s. to An. arabiensis and a relative increase in outdoor biting.
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Affiliation(s)
- Alex K Musiime
- Infectious Diseases Research Collaboration, Kampala, Uganda. .,Department of Zoology, Entomology and Fisheries Sciences, College of Natural Sciences, Makerere University, Kampala, Uganda.
| | - David L Smith
- Institute for Health Metrics & Evaluation, University of Washington, Seattle, WA, USA
| | - Maxwell Kilama
- Infectious Diseases Research Collaboration, Kampala, Uganda
| | - John Rek
- Infectious Diseases Research Collaboration, Kampala, Uganda
| | | | - Joaniter I Nankabirwa
- Infectious Diseases Research Collaboration, Kampala, Uganda.,Department of Medicine, Makerere University College of Health Sciences, Kampala, Uganda
| | - Moses R Kamya
- Infectious Diseases Research Collaboration, Kampala, Uganda.,Department of Medicine, Makerere University College of Health Sciences, Kampala, Uganda
| | - Melissa D Conrad
- Department of Medicine, University of California San Francisco, San Francisco, CA, USA
| | - Grant Dorsey
- Department of Medicine, University of California San Francisco, San Francisco, CA, USA
| | - Anne M Akol
- Department of Zoology, Entomology and Fisheries Sciences, College of Natural Sciences, Makerere University, Kampala, Uganda
| | - Sarah G Staedke
- Faculty of Infectious and Tropical Diseases, London School of Hygiene and Tropical Medicine, London, UK
| | | | - James P Egonyu
- Department of Zoology, Entomology and Fisheries Sciences, College of Natural Sciences, Makerere University, Kampala, Uganda.,International Center of Insect Physiology and Ecology, Nairobi, Kenya
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19
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Corrêa APSA, Galardo AKR, Lima LA, Câmara DCP, Müller JN, Barroso JFS, Lapouble OMM, Rodovalho CM, Ribeiro KAN, Lima JBP. Efficacy of insecticides used in indoor residual spraying for malaria control: an experimental trial on various surfaces in a "test house". Malar J 2019; 18:345. [PMID: 31601226 PMCID: PMC6785876 DOI: 10.1186/s12936-019-2969-6] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/04/2019] [Accepted: 09/21/2019] [Indexed: 11/10/2022] Open
Abstract
Background Malaria is a public health problem in the Brazilian Amazon region. In integrated vector management for malaria (anopheline) control, indoor residual spraying (IRS) represents one of the main tools in the basic strategy applied in the Amazonian states. It is essential to understand the residual efficacy of insecticides on different surfaces to determine spray cycles, ensure their rational use, and prevent wastage. This study aimed to evaluate the residual efficacy of six insecticide formulations used in the National Malaria Control Programme on four different types of walls in a field simulation at a “test house”. Methods The tests were performed as a field-simulating evaluation at a “test house” built in the municipality of Macapá. Six insecticide formulations comprising four pyrethroids, a carbamate, and an organophosphate were used, and evaluated when applied on different wall surfaces: painted wood, unpainted wood, plastered cement, and unplastered cement. The insecticides were applied to the interior walls of the “test house” by a trained technician. Results In the bioassays performed with pyrethroids, deltamethrin water-dispersible granules (WG) performed particularly well, presenting residual bioefficacy of 8 months on both wood surfaces after the IRS, whereas alpha-cypermethrin suspension concentrate (SC) and etofenprox wettable powder (WP) demonstrated residual bioefficacy of 4 months on at least one of the wood surfaces; however, the pyrethroid lambda-cyhalothrin WP showed a low residual bioefficacy (< 3 months) on all tested surfaces, demonstrating its inefficiency for areas with a long transmission cycle of malaria. For the carbamate-bendiocarb WP, residual bioefficacy for 3 months was achieved only on wood surfaces. In general, the organophosphate pirimifos-methyl capsule suspension (CS) demonstrated the best result, with a mortality rate < 80% over a period of 6 months on all surfaces tested. Conclusion Insecticide efficiency varies among different types of surface; therefore, a “test house” is a valuable evaluation tool. This work highlights the usefulness of associating the residual efficacy of insecticides on the surfaces commonly found in houses in endemic areas, together with knowledge about the transmission cycle duration of the transmission cycle and the insecticide susceptibility of the vector. This association helps in the decision-making for the malaria control intervention regarding.
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Affiliation(s)
- Ana Paula S A Corrêa
- Laboratório de Fisiologia e Controle de Artrópodes Vetores-Fundação Oswaldo Cruz, Rio de Janeiro, Brazil. .,Laboratório de Entomologia Médica, Instituto de Pesquisas Científicas e Tecnológicas do Estado de Amapá-IEPA, Macapá, Brazil.
| | - Allan K R Galardo
- Laboratório de Entomologia Médica, Instituto de Pesquisas Científicas e Tecnológicas do Estado de Amapá-IEPA, Macapá, Brazil
| | - Luana A Lima
- Laboratório de Entomologia Médica, Instituto de Pesquisas Científicas e Tecnológicas do Estado de Amapá-IEPA, Macapá, Brazil
| | - Daniel C P Câmara
- Núcleo Operacional Sentinela de Mosquitos Vetores - Laboratório de Mosquitos Transmissores de Hematozoários, Fundação Oswaldo Cruz, Rio de Janeiro, Brazil
| | - Josiane N Müller
- Laboratório de Fisiologia e Controle de Artrópodes Vetores-Fundação Oswaldo Cruz, Rio de Janeiro, Brazil.,Laboratório de Entomologia Médica, Instituto de Pesquisas Científicas e Tecnológicas do Estado de Amapá-IEPA, Macapá, Brazil
| | - Jéssica Fernanda S Barroso
- Laboratório de Entomologia Médica, Instituto de Pesquisas Científicas e Tecnológicas do Estado de Amapá-IEPA, Macapá, Brazil
| | - Oscar M M Lapouble
- Pan-American Health Organization/World Health Organization (PAHO/WHO), Paramaribo, Suriname.,Fundação de Medicina Tropical Dr. Heitor Vieira Dourado, Manaus, Amazonas, Brazil.,Programa de Pós-Graduação em Medicina Tropical, Universidade do Estado do Amazonas, Manaus, Amazonas, Brazil
| | - Cynara M Rodovalho
- Laboratório de Fisiologia e Controle de Artrópodes Vetores-Fundação Oswaldo Cruz, Rio de Janeiro, Brazil
| | | | - José Bento P Lima
- Laboratório de Fisiologia e Controle de Artrópodes Vetores-Fundação Oswaldo Cruz, Rio de Janeiro, Brazil
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20
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Ngwej LM, Hattingh I, Mlambo G, Mashat EM, Kashala JCK, Malonga FK, Bangs MJ. Indoor residual spray bio-efficacy and residual activity of a clothianidin-based formulation (SumiShield ® 50WG) provides long persistence on various wall surfaces for malaria control in the Democratic Republic of the Congo. Malar J 2019; 18:72. [PMID: 30866934 PMCID: PMC6417189 DOI: 10.1186/s12936-019-2710-5] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/13/2018] [Accepted: 03/06/2019] [Indexed: 11/10/2022] Open
Abstract
Background Bio-efficacy and residual activity of SumiShield® 50WG (50%, w/w) with active ingredient clothianidin, a neonicotinoid compound, was assessed using an insecticide-susceptible laboratory strain of Anopheles arabiensis. Implications of the findings are examined in the context of potential alternative insecticides for indoor residual spraying in Lualaba Province, Democratic Republic of the Congo. Methods Contact surface bioassays were conducted for 48 weeks on four types of walls (unbaked clay, baked clay, cement, painted cement) in simulated semi-field experimental conditions using two different doses of clothianidin active ingredient (200 mg ai/sq m and 300 mg ai/sq m). Additionally, two types of walls (painted cement and baked clay) were examined in occupied houses using the 300-mg dosage. Laboratory-reared An. arabiensis were exposed to treated surfaces or untreated (controls) for 30 min. Mortality was recorded at 24-h intervals for 120 h. Results Under semi-field experimental conditions, there was no significant difference in mortality over time between the two doses of clothianidin. The mortality rates remained above 60% up to 48 weeks on all four wall surface types. The formulation performed better on cement and unbaked clay with a mean final mortality rate above 90%. Under natural conditions, there was no significant difference in response between baked clay and painted cement walls with a mean final mortality rate above 90%. The insecticide also performed significantly better in natural settings compared to semi-field experimental conditions. Conclusion Depending on the type of experimental surface, the residual activity of the two doses of clothianidin was between 28 and 48 weeks based on a 60% mortality endpoint. Clothianidin at 300 mg ai/sq m applied on two house walls (baked clay or painted cement) performed equally well (> 80% mortality) on both surfaces up to week 41 (approximately 9.5 months). Extended bioassay holding periods (up to 120 h) may present with excess natural mortality in the untreated controls, thus complicating analysis.
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Affiliation(s)
- Leonard M Ngwej
- China Molybdenum Co., Ltd./International SOS Malaria Control Programme, Tenke Fungurume Mining, Fungurume, Lualaba Province, Democratic Republic of the Congo. .,School of Public Health, University of Lubumbashi, Lubumbashi, Democratic Republic of the Congo.
| | - Izak Hattingh
- China Molybdenum Co., Ltd./International SOS Malaria Control Programme, Tenke Fungurume Mining, Fungurume, Lualaba Province, Democratic Republic of the Congo
| | - Godwill Mlambo
- China Molybdenum Co., Ltd./International SOS Malaria Control Programme, Tenke Fungurume Mining, Fungurume, Lualaba Province, Democratic Republic of the Congo
| | - Emmanuel M Mashat
- China Molybdenum Co., Ltd./International SOS Malaria Control Programme, Tenke Fungurume Mining, Fungurume, Lualaba Province, Democratic Republic of the Congo
| | - Jean-Christophe K Kashala
- Faculty of Veterinary Medicine, University of Lubumbashi, Lubumbashi, Democratic Republic of the Congo
| | - Françoise K Malonga
- School of Public Health, University of Lubumbashi, Lubumbashi, Democratic Republic of the Congo
| | - Michael J Bangs
- China Molybdenum Co., Ltd./International SOS Malaria Control Programme, Tenke Fungurume Mining, Fungurume, Lualaba Province, Democratic Republic of the Congo.,Public Health & Malaria Control Department, PT Freeport Indonesia, International SOS, Jl. Kertajasa, Kuala Kencana, Papua, 99920, Indonesia.,Department of Entomology, Faculty of Agriculture, Kasetsart University, Bangkok, 10900, Thailand
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21
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Tugume A, Muneza F, Oporia F, Kiconco A, Kihembo C, Kisakye AN, Nsubuga P, Deogratias S, Yeka A. Effects and factors associated with indoor residual spraying with Actellic 300 CS on malaria morbidity in Lira District, Northern Uganda. Malar J 2019; 18:44. [PMID: 30791906 PMCID: PMC6383239 DOI: 10.1186/s12936-019-2681-6] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/31/2018] [Accepted: 02/14/2019] [Indexed: 11/10/2022] Open
Abstract
BACKGROUND Indoor residual spraying (IRS) with Actellic 300 CS was conducted in Lira District between July and August 2016. No formal assessment has been conducted to estimate the effect of spraying with Actellic 300 CS on malaria morbidity in the Ugandan settings. This study assessed malaria morbidity trends before and after IRS with Actellic 300 CS in Lira District in Northern Uganda. METHODS The study employed a mixed methods design. Malaria morbidity records from four health facilities were reviewed, focusing on 6 months before and after the IRS intervention. The outcome of interest was malaria morbidity defined as; proportion of outpatient attendance due to total malaria, proportion of outpatient attendance due to confirmed malaria and proportion of malaria case numbers confirmed by microscopy or rapid diagnostic test. Since malaria morbidity was based on count data, an ordinary Poisson regression model was used to obtain percentage point change (pp) in monthly malaria cases before and after IRS. A household survey was also conducted in 159 households to determine IRS coverage and factors associated with spraying. A modified Poisson regression model was fitted to determine factors associated with household spray status. RESULTS The proportion of outpatient attendance due to malaria dropped from 18.7% before spraying to 15.1% after IRS. The proportion of outpatient attendance due to confirmed malaria also dropped from 5.1% before spraying to 4.0% after the IRS intervention. There was a decreasing trend in malaria test positivity rate (TPR) for every unit increase in month after spraying. The decreasing trend in TPR was more prominent 5-6 months after the IRS intervention (Adj. pp = - 0.60, P-value = 0.015; Adj. pp = - 1.19, P-value < 0.001). The IRS coverage was estimated at 89.3%. Households of respondents who were formally employed or owned any form of business were more likely to be unsprayed; (APR = 5.81, CI 2.72-12.68); (APR = 3.84, CI 1.20-12.31), respectively. CONCLUSION Coverage of IRS with Actellic 300 CS was high and was associated with a significant decline in malaria related morbidity 6 months after spraying.
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Affiliation(s)
- Abdulaziz Tugume
- Department of Epidemiology and Biostatistics, College of Health Sciences, School of Public Health, Makerere University, P.O.BOX, 7072, Kampala, Uganda.
| | - Fiston Muneza
- Department of Epidemiology and Biostatistics, College of Health Sciences, School of Public Health, Makerere University, P.O.BOX, 7072, Kampala, Uganda
| | - Frederick Oporia
- Department of Disease Control and Environmental Health, College of Health Sciences, School of Public Health, Makerere University, Kampala, Uganda
| | - Arthur Kiconco
- Department of Disease Control and Environmental Health, College of Health Sciences, School of Public Health, Makerere University, Kampala, Uganda
| | | | - Angela Nakanwagi Kisakye
- Department of Health Policy Planning and Management, Makerere University School of Public Health, Kampala, Uganda.,African Field Epidemiology Network, Kampala, Uganda
| | | | - Sekimpi Deogratias
- Department of Disease Control and Environmental Health, College of Health Sciences, School of Public Health, Makerere University, Kampala, Uganda
| | - Adoke Yeka
- Department of Disease Control and Environmental Health, College of Health Sciences, School of Public Health, Makerere University, Kampala, Uganda
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22
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Ogwang R, Akena G, Yeka A, Osier F, Idro R. The 2015-2016 malaria epidemic in Northern Uganda; What are the implications for malaria control interventions? Acta Trop 2018; 188:27-33. [PMID: 30145260 PMCID: PMC7116666 DOI: 10.1016/j.actatropica.2018.08.023] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/24/2018] [Revised: 08/17/2018] [Accepted: 08/17/2018] [Indexed: 02/03/2023]
Abstract
Vector control and effective case management are currently the backbone strategies of malaria control. Kitgum district, an area of perennial holoendemic malaria transmission intensity in Northern Uganda, appears to have experienced a malaria epidemic in 2015. This study aimed to describe the malaria trends in Kitgum General Hospital from 2011 to 2017 in relation to climatic factors and the application of population-based malaria control interventions. Hospital records were examined retrospectively to calculate malaria normal channels, malaria cases per 1000 population, test positivity rates (TPR) and to enumerate pregnancy malaria, hospitalizations and deaths. Climatic factors (humidity, temperature and rainfall) and population-based malaria control interventions that had been applied during this period were described. Kitgum district experienced an epidemic between the years 2015 and 2016; the malaria burden rose above the established normal channels. At its peak the number of malaria cases attending KGH was over 20 times above the normal channels. The total number of cases per 1000 population increased from 7 in 2014 to 113 in 2015 and 114 in 2016 (p value for trend <0.0001). Similarly, TPR increased from 10.5% to 54.6% between 2014 and 2016 (p value for trend <0.0001). This trend was also observed for malaria attributable hospitalizations, and malaria in pregnancy. There were no significant changes in any of the climatic factors assessed (p value = 0.92, 0.99, 0.52 for relative humidity, max temperature, and rainfall, respectively). The malaria upsurge occurred in conjunction with a general decline in the use and application of malaria control interventions. Specifically, indoor residual spraying was interrupted in 2014. In response to the epidemic, IRS was reapplied together with mass distribution of long-lasting insecticide treated nets (LLINs) in 2017. Subsequently, there was a decline in all malaria indicators. The epidemic in Kitgum occurred in association with the interruption of IRS and appears to have abated following its re-introduction alongside LLINs. The study suggests that to enable malaria elimination in areas of high malaria transmission intensity, effective control measures may need to be sustained for the long-term.
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Affiliation(s)
- Rodney Ogwang
- Makerere University College of Health Sciences, Kampala, Uganda; Centre of Tropical Neuroscience, Kitgum Site, Uganda
| | | | - Adoke Yeka
- Makerere University College of Health Sciences, Kampala, Uganda
| | - Faith Osier
- Centre for Infectious Diseases, Parasitology Heidelberg University Hospital, Heidelberg, Germany; KEMRI-Wellcome Trust Research Programme, Centre for Geographic Medicine Coast, Kilifi, Kenya
| | - Richard Idro
- Makerere University College of Health Sciences, Kampala, Uganda; Centre of Tropical Neuroscience, Kitgum Site, Uganda; Centre for Tropical Medicine and Global Health, Nuffield Department of Medicine, University of Oxford, Oxford, UK.
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23
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Wagman J, Gogue C, Tynuv K, Mihigo J, Bankineza E, Bah M, Diallo D, Saibu A, Richardson JH, Kone D, Fomba S, Bernson J, Steketee R, Slutsker L, Robertson M. An observational analysis of the impact of indoor residual spraying with non-pyrethroid insecticides on the incidence of malaria in Ségou Region, Mali: 2012-2015. Malar J 2018; 17:19. [PMID: 29316917 PMCID: PMC5761159 DOI: 10.1186/s12936-017-2168-2] [Citation(s) in RCA: 23] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/10/2017] [Accepted: 12/29/2017] [Indexed: 11/10/2022] Open
Abstract
Background Ségou Region in Central Mali is an area of high malaria burden with seasonal transmission, high access to and use of long-lasting insecticidal nets (LLINs), and resistance to pyrethroids and DDT well documented in Anopheles gambiae s.l. (the principal vector of malaria in Mali). Ségou has recently received indoor residual spraying (IRS) supported by Mali’s collaboration with the US President’s Malaria Initiative/Africa Indoor Residual Spraying programme. From 2012 to 2015, two different non-pyrethroid insecticides: bendiocarb in 2012 and 2013 and pirimiphos-methyl in 2014 and 2015, were used for IRS in two districts. This report summarizes the results of observational analyses carried out to assess the impact of these IRS campaigns on malaria incidence rates reported through local and district health systems before and after spraying. Methods A series of retrospective time series analyses were performed on 1,382,202 rapid diagnostic test-confirmed cases of malaria reported by district routine health systems in Ségou Region from January 2012 to January 2016. Malaria testing, treatment, surveillance and reporting activities remained consistent across districts and years during the study period, as did LLIN access and use estimates as well as An. gambiae s.l. insecticide resistance patterns. Districts were stratified by IRS implementation status and all-age monthly incidence rates were calculated and compared across strata from 2012 to 2014. In 2015 a regional but variable scale-up of seasonal malaria chemoprevention complicated the region-wide analysis; however IRS operations were suspended in Bla District that year so a difference in differences approach was used to compare 2014 to 2015 changes in malaria incidence at the health facility level in children under 5-years-old from Bla relative to changes observed in Barouéli, where IRS operations were consistent. Results During 2012–2014, rapid reductions in malaria incidence were observed during the 6 months following each IRS campaign, though most of the reduction in cases (70% of the total) was concentrated in the first 2 months after each campaign was completed. Compared to non-IRS districts, in which normal seasonal patterns of malaria incidence were observed, an estimated 286,745 total fewer cases of all-age malaria were observed in IRS districts. The total cost of IRS in Ségou was around 9.68 million USD, or roughly 33.75 USD per case averted. Further analysis suggests that the timing of the 2012–2014 IRS campaigns (spraying in July and August) was well positioned to maximize public health impact. Suspension of IRS in Bla District after the 2014 campaign resulted in a 70% increase in under-5-years-old malaria incidence rates from 2014 to 2015, significantly greater (p = 0.0003) than the change reported from Barouéli District, where incidence rates remained the same. Conclusions From 2012 to 2015, the annual IRS campaigns in Ségou are associated with several hundred thousand fewer cases of malaria. This work supports the growing evidence that shows that IRS with non-pyrethroid insecticides is a wise public health investment in areas with documented pyrethroid resistance, high rates of LLIN coverage, and where house structures and population densities are appropriate. Additionally, this work highlights the utility of quality-assured and validated routine surveillance and well defined observational analyses to rapidly assess the impact of malaria control interventions in operational settings, helping to empower evidence-based decision making and to further grow the evidence base needed to better understand when and where to utilize new vector control tools as they become available. Electronic supplementary material The online version of this article (10.1186/s12936-017-2168-2) contains supplementary material, which is available to authorized users.
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Affiliation(s)
| | | | | | | | | | | | | | | | | | - Diakalkia Kone
- Programme National de Lutte Contre le Paludisme, Bamako, Mali
| | - Seydou Fomba
- Programme National de Lutte Contre le Paludisme, Bamako, Mali
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Katrak S, Murphy M, Nayebare P, Rek J, Smith M, Arinaitwe E, Nankabirwa JI, Kamya M, Dorsey G, Rosenthal PJ, Greenhouse B. Performance of Loop-Mediated Isothermal Amplification for the Identification of Submicroscopic Plasmodium falciparum Infection in Uganda. Am J Trop Med Hyg 2017; 97:1777-1781. [PMID: 29016335 PMCID: PMC5805042 DOI: 10.4269/ajtmh.17-0225] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022] Open
Abstract
Accurately identifying and targeting the human reservoir of malaria parasitemia is critical for malaria control, and requires a reliable and sensitive diagnostic method. Loop-mediated isothermal amplification (LAMP) is increasingly used to diagnose submicroscopic parasitemia. Although most published studies report the sensitivity of LAMP compared with nested polymerase chain reaction (PCR) as ≥ 80%, they have failed to use a consistent, sensitive diagnostic as a comparator. We used cross-sectional samples from children and adults in Tororo, Uganda, a region with high but declining transmission due to indoor residual spraying, to characterize the sensitivity and specificity of pan-Plasmodium LAMP for detecting submicroscopic infections. We compared LAMP results targeting a mitochondrial DNA sequence conserved in all Plasmodium species, performed on DNA extracted from dried blood spots, to those of a gold standard quantitative PCR assay targeting the var gene acidic terminal sequence of Plasmodium falciparum (varATS qPCR), performed on DNA extracted from 200 µL of whole blood. Using LAMP and varATS qPCR increased the detection of parasitemia 2- to 5-fold, compared with microscopy. Among microscopy-negative samples, the sensitivity of LAMP was 81.5% for detecting infection ≥ 1 parasites/µL. However, low density infections were common, and LAMP failed to identify more than half of all infections diagnosed by varATS qPCR, performing with an overall sensitivity of 44.7% for detecting submicroscopic infections ≥ 0.01 parasites/µL. Thus, although the LAMP assay is more sensitive than microscopy, it missed a significant portion of the submicroscopic reservoir. These findings have important implications for malaria control, particularly in settings where low-density infections predominate.
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Affiliation(s)
- Shereen Katrak
- Department of Medicine, University of California San Francisco, San Francisco, California;,Address correspondence to Shereen Katrak, Department of Medicine, University of California San Francisco, 513 Parnassus Avenue, Room S380, Box 0654, San Francisco, CA 94143. E-mail:
| | - Maxwell Murphy
- Department of Medicine, University of California San Francisco, San Francisco, California
| | | | - John Rek
- Infectious Diseases Research Collaboration, Kampala, Uganda
| | - Mary Smith
- Chicago Medical School, Rosalind Franklin University, North Chicago, Illinois
| | - Emmanuel Arinaitwe
- Infectious Diseases Research Collaboration, Kampala, Uganda;,London School of Hygiene and Tropical Medicine, London, United Kingdom
| | - Joaniter I. Nankabirwa
- Infectious Diseases Research Collaboration, Kampala, Uganda;,School of Medicine, Makerere University College of Health Sciences, Kampala, Uganda
| | - Moses Kamya
- Infectious Diseases Research Collaboration, Kampala, Uganda;,School of Medicine, Makerere University College of Health Sciences, Kampala, Uganda
| | - Grant Dorsey
- Department of Medicine, University of California San Francisco, San Francisco, California
| | - Philip J. Rosenthal
- Department of Medicine, University of California San Francisco, San Francisco, California
| | - Bryan Greenhouse
- Department of Medicine, University of California San Francisco, San Francisco, California
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