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Tairou F, Gaye I, Herrera S, Nawaz S, Sarr L, Cissé B, Faye B, Tine RCK. Malaria prevalence and use of control measures in an area with persistent transmission in Senegal. PLoS One 2024; 19:e0303794. [PMID: 38753670 PMCID: PMC11098374 DOI: 10.1371/journal.pone.0303794] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/20/2023] [Accepted: 04/30/2024] [Indexed: 05/18/2024] Open
Abstract
INTRODUCTION In Senegal, the widespread use of vector control measures has resulted in a significant reduction in the malaria burden and led the country to consider the possibility of elimination. Given this shift and changing context, it is important to characterize the malaria burden across all age groups to guide decision-making on programmatic interventions to interrupt transmission and ultimately eradicate the disease. In Senegal, there is a lack of information on malaria prevalence among certain populations, particularly among adolescents and adults. This study sought to assess the magnitude of malaria infections in all age groups, as well as malaria associated factors in an area of persistent transmission in Senegal. METHODS A cross-sectional household survey was conducted in four health posts (Khossanto, Mamakhona, Diakhaling and Sambrambougou), of the health district of Saraya, in November 2021, among individuals over 6 months of age. Households were selected using multistage sampling. Consented participants were screened for malaria parasites by microscopic examination of blood smears, and hemoglobin levels were measured using the Hemocue HB 301TM analyzer. Socio-demographic information of the participants, household heads, household assets, and information on ownership and use of preventive measures were collected using a structured questionnaire. Weighted generalized mixed effects logistic regression model was used to identify factors associated with microscopically confirmed malaria infection. RESULTS A total of 1759 participants were enrolled in the study. Overall, about 21% of participants were classified as having Plasmodium infection; children aged 5-10 years old (26.6%), adolescents aged 10-19 years old (24.7%), and children under five years of age (20.5%) had higher rates of infection compared to adults (13.5%). Plasmodium falciparum accounted for 99.2% of the malaria infections, and most infections (69%) were asymptomatic. Around one-third of study participants had anemia (hemoglobin level <11.0 g/dl), with under five children bearing the highest burden (67.3%). Multivariate analysis showed that the odds of having a malaria infection were around 2 times higher among participants in Khossanto compared to Diakhaling (aOR = 1.84, 95% CI:1.06-3.20). Participants aged 5-9 years were more likely to have malaria infection compared to under five children (aOR = 1.40, 95% CI:1.02-1.91). Factors associated with anemia were P. falciparum infection (aOR = 1.36, p = 0.027), females (aOR = 2.16, p = 0.000), under-five age group (aOR = 13.01, p = 0.000). CONCLUSION Malaria burden was considerable among adolescents and under ten children living in an area of persistent transmission, with adolescents more commonly presenting as asymptomatic. Interventions tailored to this specific group of the population are needed to better control the disease and reduce its burden.
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Affiliation(s)
- Fassiatou Tairou
- Department of Medical Parasitology, University Cheikh Anta Diop of Dakar, Dakar, Senegal
| | - Ibrahima Gaye
- Institut en Santé et Développement, University Cheikh Anta Diop of Dakar, Dakar, Senegal
| | - Samantha Herrera
- Malaria & Neglected Tropical Diseases Division, PATH, Washington, District of Columbia, United States of America
| | - Saira Nawaz
- Primary Health Care, PATH, Seattle, Washington, United States of America
| | - Libasse Sarr
- Department of Geography, University Cheikh Anta Diop of Dakar, Dakar, Senegal
| | - Birane Cissé
- Department of Geography, University Cheikh Anta Diop of Dakar, Dakar, Senegal
| | - Babacar Faye
- Department of Medical Parasitology, University Cheikh Anta Diop of Dakar, Dakar, Senegal
| | - Roger C. K. Tine
- Department of Medical Parasitology, University Cheikh Anta Diop of Dakar, Dakar, Senegal
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Ndiaye F, Diop A, Chabi J, Sturm-Ramirez K, Senghor M, Diouf EH, Samb B, Diedhiou SM, Thiaw O, Zohdy S, Dotson E, Sene D, Diouf MB, Koscelnik V, Gerberg L, Bangoura A, Clark T, Faye O, Dia I, Konate L, Niang EHA. Distribution and dynamics of Anopheles gambiae s.l. larval habitats in three Senegalese cities with high urban malaria incidence. PLoS One 2024; 19:e0303473. [PMID: 38743768 PMCID: PMC11093314 DOI: 10.1371/journal.pone.0303473] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/24/2023] [Accepted: 04/15/2024] [Indexed: 05/16/2024] Open
Abstract
Urban malaria has become a challenge for most African countries due to urbanization, with increasing population sizes, overcrowding, and movement into cities from rural localities. The rapid expansion of cities with inappropriate water drainage systems, abundance of water storage habitats, coupled with recurrent flooding represents a concern for water-associated vector borne diseases, including malaria. This situation could threaten progress made towards malaria elimination in sub-Saharan countries, including Senegal, where urban malaria has presented as a threat to national elimination gains. To assess drivers of urban malaria in Senegal, a 5-month study was carried out from August to December 2019 in three major urban areas and hotspots for malaria incidence (Diourbel, Touba, and Kaolack) including the rainy season (August-October) and partly dry season (November-December). The aim was to characterize malaria vector larval habitats, vector dynamics across both seasons, and to identify the primary eco- environmental entomological factors contributing to observed urban malaria transmission. A total of 145 Anopheles larval habitats were found, mapped, and monitored monthly. This included 32 in Diourbel, 83 in Touba, and 30 in Kaolack. The number of larval habitats fluctuated seasonally, with a decrease during the dry season. In Diourbel, 22 of the 32 monitored larval habitats (68.75%) were dried out by December and considered temporary, while the remaining 10 (31.25%) were classified as permanent. In the city of Touba 28 (33.73%) were temporary habitats, and of those 57%, 71% and 100% dried up respectively by October, November, and December. However, 55 (66.27%) habitats were permanent water storage basins which persisted throughout the study. In Kaolack, 12 (40%) permanent and 18 (60%) temporary Anopheles larval habitats were found and monitored during the study. Three malaria vectors (An. arabiensis, An. pharoensis and An. funestus s.l.) were found across the surveyed larval habitats, and An. arabiensis was found in all three cities and was the only species found in the city of Diourbel, while An. arabiensis, An. pharoensis, and An. funestus s.l. were detected in the cities of Touba and Kaolack. The spatiotemporal observations of immature malaria vectors in Senegal provide evidence of permanent productive malaria vector larval habitats year-round in three major urban centers in Senegal, which may be driving high urban malaria incidence. This study aimed to assess the presence and type of anopheline larvae habitats in urban areas. The preliminary data will better inform subsequent detailed additional studies and seasonally appropriate, cost-effective, and sustainable larval source management (LSM) strategies by the National Malaria Control Programme (NMCP).
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Affiliation(s)
- Fatou Ndiaye
- Laboratoire d’Ecologie Vectorielle et Parasitaire, Université Cheikh Anta Diop de Dakar, Dakar, Sénégal
| | - Abdoulaye Diop
- Laboratoire d’Ecologie Vectorielle et Parasitaire, Université Cheikh Anta Diop de Dakar, Dakar, Sénégal
- U.S. President’s Malaria Initiative VectorLink Project, Dakar, Senegal
| | - Joseph Chabi
- U.S. PMI VectorLink Project, Abt Associates, Rockville, MD, United States of America
| | | | - Massila Senghor
- Laboratoire d’Ecologie Vectorielle et Parasitaire, Université Cheikh Anta Diop de Dakar, Dakar, Sénégal
| | - El Hadji Diouf
- Laboratoire d’Ecologie Vectorielle et Parasitaire, Université Cheikh Anta Diop de Dakar, Dakar, Sénégal
| | - Badara Samb
- Laboratoire d’Ecologie Vectorielle et Parasitaire, Université Cheikh Anta Diop de Dakar, Dakar, Sénégal
| | - Seynabou Mocote Diedhiou
- Laboratoire d’Ecologie Vectorielle et Parasitaire, Université Cheikh Anta Diop de Dakar, Dakar, Sénégal
| | - Omar Thiaw
- Laboratoire d’Ecologie Vectorielle et Parasitaire, Université Cheikh Anta Diop de Dakar, Dakar, Sénégal
| | - Sarah Zohdy
- U.S President’s Malaria Initiative, Centers for Disease Control and Prevention (CDC), Atlanta, GA, United States of America
| | - Ellen Dotson
- U.S President’s Malaria Initiative, Centers for Disease Control and Prevention (CDC), Atlanta, GA, United States of America
| | - Doudou Sene
- National Malaria Control Programme, Dakar, Senegal
| | | | | | - Lilia Gerberg
- U.S. President’s Malaria Initiative, United States Agency for International Development (USAID), Washington, DC, United States of America
| | - Abdoulaye Bangoura
- U.S. PMI VectorLink Project, Abt Associates, Rockville, MD, United States of America
| | - Tiffany Clark
- U.S. PMI VectorLink Project, Abt Associates, Rockville, MD, United States of America
| | - Ousmane Faye
- Laboratoire d’Ecologie Vectorielle et Parasitaire, Université Cheikh Anta Diop de Dakar, Dakar, Sénégal
| | - Ibrahima Dia
- Institut Pasteur de Dakar, Unité d’Entomologie Médicale, Dakar, Senegal
| | - Lassana Konate
- Laboratoire d’Ecologie Vectorielle et Parasitaire, Université Cheikh Anta Diop de Dakar, Dakar, Sénégal
| | - El Hadji Amadou Niang
- Laboratoire d’Ecologie Vectorielle et Parasitaire, Université Cheikh Anta Diop de Dakar, Dakar, Sénégal
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Levine ZC, Sene A, Mkandawire W, Deme AB, Ndiaye T, Sy M, Gaye A, Diedhiou Y, Mbaye AM, Ndiaye IM, Gomis J, Ndiop M, Sene D, Faye Paye M, MacInnis BL, Schaffner SF, Park DJ, Badiane AS, Colubri A, Ndiaye M, Sy N, Sabeti PC, Ndiaye D, Siddle KJ. Investigating the etiologies of non-malarial febrile illness in Senegal using metagenomic sequencing. Nat Commun 2024; 15:747. [PMID: 38272885 PMCID: PMC10810818 DOI: 10.1038/s41467-024-44800-7] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/22/2023] [Accepted: 01/04/2024] [Indexed: 01/27/2024] Open
Abstract
The worldwide decline in malaria incidence is revealing the extensive burden of non-malarial febrile illness (NMFI), which remains poorly understood and difficult to diagnose. To characterize NMFI in Senegal, we collected venous blood and clinical metadata in a cross-sectional study of febrile patients and healthy controls in a low malaria burden area. Using 16S and untargeted sequencing, we detected viral, bacterial, or eukaryotic pathogens in 23% (38/163) of NMFI cases. Bacteria were the most common, with relapsing fever Borrelia and spotted fever Rickettsia found in 15.5% and 3.8% of cases, respectively. Four viral pathogens were found in a total of 7 febrile cases (3.5%). Sequencing also detected undiagnosed Plasmodium, including one putative P. ovale infection. We developed a logistic regression model that can distinguish Borrelia from NMFIs with similar presentation based on symptoms and vital signs (F1 score: 0.823). These results highlight the challenge and importance of improved diagnostics, especially for Borrelia, to support diagnosis and surveillance.
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Affiliation(s)
- Zoë C Levine
- Broad Institute of Harvard and MIT, Cambridge, MA, USA
- Harvard Graduate Program in Biological and Biomedical Science, Boston, MA, USA
- Harvard/MIT MD-PhD Program, Boston, MA, USA
| | - Aita Sene
- Department of Parasitology, Cheikh Anta Diop University Dakar, Dakar, Senegal
- Centre International de Recherche et de Formation en Génomique Appliquée et de la Surveillance Sanitaire, Dakar, Senegal
| | - Winnie Mkandawire
- Broad Institute of Harvard and MIT, Cambridge, MA, USA
- University of Massachusetts Medical School, Worcester, MA, USA
| | - Awa B Deme
- Centre International de Recherche et de Formation en Génomique Appliquée et de la Surveillance Sanitaire, Dakar, Senegal
| | - Tolla Ndiaye
- Department of Parasitology, Cheikh Anta Diop University Dakar, Dakar, Senegal
- Centre International de Recherche et de Formation en Génomique Appliquée et de la Surveillance Sanitaire, Dakar, Senegal
| | - Mouhamad Sy
- Department of Parasitology, Cheikh Anta Diop University Dakar, Dakar, Senegal
- Centre International de Recherche et de Formation en Génomique Appliquée et de la Surveillance Sanitaire, Dakar, Senegal
| | - Amy Gaye
- Department of Parasitology, Cheikh Anta Diop University Dakar, Dakar, Senegal
- Centre International de Recherche et de Formation en Génomique Appliquée et de la Surveillance Sanitaire, Dakar, Senegal
| | - Younouss Diedhiou
- Department of Parasitology, Cheikh Anta Diop University Dakar, Dakar, Senegal
- Centre International de Recherche et de Formation en Génomique Appliquée et de la Surveillance Sanitaire, Dakar, Senegal
| | - Amadou M Mbaye
- Department of Parasitology, Cheikh Anta Diop University Dakar, Dakar, Senegal
- Centre International de Recherche et de Formation en Génomique Appliquée et de la Surveillance Sanitaire, Dakar, Senegal
| | - Ibrahima M Ndiaye
- Department of Parasitology, Cheikh Anta Diop University Dakar, Dakar, Senegal
- Centre International de Recherche et de Formation en Génomique Appliquée et de la Surveillance Sanitaire, Dakar, Senegal
| | - Jules Gomis
- Department of Parasitology, Cheikh Anta Diop University Dakar, Dakar, Senegal
- Centre International de Recherche et de Formation en Génomique Appliquée et de la Surveillance Sanitaire, Dakar, Senegal
| | - Médoune Ndiop
- Programme National de lutte contre le Paludisme, Ministère de la Santé, Dakar Fann, Senegal
| | - Doudou Sene
- Programme National de lutte contre le Paludisme, Ministère de la Santé, Dakar Fann, Senegal
| | | | - Bronwyn L MacInnis
- Broad Institute of Harvard and MIT, Cambridge, MA, USA
- Department of Immunology and Infectious Diseases, Harvard T.H. Chan School of Public Health, Harvard University, Boston, MA, USA
| | - Stephen F Schaffner
- Broad Institute of Harvard and MIT, Cambridge, MA, USA
- Department of Immunology and Infectious Diseases, Harvard T.H. Chan School of Public Health, Harvard University, Boston, MA, USA
- Department of Organismic and Evolutionary Biology, Harvard University, Cambridge, MA, USA
| | - Daniel J Park
- Broad Institute of Harvard and MIT, Cambridge, MA, USA
| | - Aida S Badiane
- Department of Parasitology, Cheikh Anta Diop University Dakar, Dakar, Senegal
- Centre International de Recherche et de Formation en Génomique Appliquée et de la Surveillance Sanitaire, Dakar, Senegal
| | - Andres Colubri
- Broad Institute of Harvard and MIT, Cambridge, MA, USA
- University of Massachusetts Medical School, Worcester, MA, USA
| | - Mouhamadou Ndiaye
- Department of Parasitology, Cheikh Anta Diop University Dakar, Dakar, Senegal
- Centre International de Recherche et de Formation en Génomique Appliquée et de la Surveillance Sanitaire, Dakar, Senegal
| | - Ngayo Sy
- Service de Lutte Anti Parasitaire, Thies, Senegal
| | - Pardis C Sabeti
- Broad Institute of Harvard and MIT, Cambridge, MA, USA.
- Department of Immunology and Infectious Diseases, Harvard T.H. Chan School of Public Health, Harvard University, Boston, MA, USA.
- Department of Organismic and Evolutionary Biology, Harvard University, Cambridge, MA, USA.
- Howard Hughes Medical Institute, Chevy Chase, MD, USA.
| | - Daouda Ndiaye
- Department of Parasitology, Cheikh Anta Diop University Dakar, Dakar, Senegal.
- Centre International de Recherche et de Formation en Génomique Appliquée et de la Surveillance Sanitaire, Dakar, Senegal.
| | - Katherine J Siddle
- Broad Institute of Harvard and MIT, Cambridge, MA, USA.
- Department of Molecular Microbiology and Immunology, Brown University, Providence, RI, USA.
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Levine ZC, Sene A, Mkandawire W, Deme AB, Ndiaye T, Sy M, Gaye A, Diedhiou Y, Mbaye AM, Ndiaye I, Gomis J, Ndiop M, Sene D, Paye MF, MacInnis B, Schaffner SF, Park DJ, Badiane AS, Colubri A, Ndiaye M, Sy N, Sabeti PC, Ndiaye D, Siddle KJ. Improving diagnosis of non-malarial fevers in Senegal: Borrelia and the contribution of tick-borne bacteria. MEDRXIV : THE PREPRINT SERVER FOR HEALTH SCIENCES 2023:2023.08.24.23294564. [PMID: 37662407 PMCID: PMC10473814 DOI: 10.1101/2023.08.24.23294564] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 09/05/2023]
Abstract
The worldwide decline in malaria incidence is revealing the extensive burden of non-malarial febrile illness (NMFI), which remains poorly understood and difficult to diagnose. To characterize NMFI in Senegal, we collected venous blood and clinical metadata from febrile patients and healthy controls in a low malaria burden area. Using 16S and unbiased sequencing, we detected viral, bacterial, or eukaryotic pathogens in 29% of NMFI cases. Bacteria were the most common, with relapsing fever Borrelia and spotted fever Rickettsia found in 15% and 3.7% of cases, respectively. Four viral pathogens were found in a total of 7 febrile cases (3.5%). Sequencing also detected undiagnosed Plasmodium, including one putative P. ovale infection. We developed a logistic regression model to distinguish Borrelia from NMFIs with similar presentation based on symptoms and vital signs. These results highlight the challenge and importance of improved diagnostics, especially for Borrelia, to support diagnosis and surveillance.
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Affiliation(s)
- Zoë C Levine
- Broad Institute of Harvard and MIT, Cambridge, MA, USA
- Harvard Graduate Program in Biological and Biomedical Science, Boston, MA, USA
- Harvard/MIT MD-PhD Program, Boston, MA, 02115, USA
| | - Aita Sene
- Centre International de recherche, de formation en Génomique Appliquée et de Surveillance Sanitaire (CIGASS), Dakar, Senegal
| | - Winnie Mkandawire
- Broad Institute of Harvard and MIT, Cambridge, MA, USA
- University of Massachusetts Medical School, Worcester, MA, USA
| | - Awa B Deme
- Centre International de recherche, de formation en Génomique Appliquée et de Surveillance Sanitaire (CIGASS), Dakar, Senegal
| | - Tolla Ndiaye
- Centre International de recherche, de formation en Génomique Appliquée et de Surveillance Sanitaire (CIGASS), Dakar, Senegal
| | - Mouhamad Sy
- Centre International de recherche, de formation en Génomique Appliquée et de Surveillance Sanitaire (CIGASS), Dakar, Senegal
| | - Amy Gaye
- Centre International de recherche, de formation en Génomique Appliquée et de Surveillance Sanitaire (CIGASS), Dakar, Senegal
| | - Younouss Diedhiou
- Centre International de recherche, de formation en Génomique Appliquée et de Surveillance Sanitaire (CIGASS), Dakar, Senegal
| | - Amadou M Mbaye
- Centre International de recherche, de formation en Génomique Appliquée et de Surveillance Sanitaire (CIGASS), Dakar, Senegal
| | - Ibrahima Ndiaye
- Centre International de recherche, de formation en Génomique Appliquée et de Surveillance Sanitaire (CIGASS), Dakar, Senegal
| | - Jules Gomis
- Centre International de recherche, de formation en Génomique Appliquée et de Surveillance Sanitaire (CIGASS), Dakar, Senegal
| | - Médoune Ndiop
- Programme National de Lutte contre le Paludisme (PNLP), Ministère de la Santé, Dakar Fann, Senegal
| | - Doudou Sene
- Programme National de Lutte contre le Paludisme (PNLP), Ministère de la Santé, Dakar Fann, Senegal
| | | | - Bronwyn MacInnis
- Broad Institute of Harvard and MIT, Cambridge, MA, USA
- Department of Immunology and Infectious Diseases, Harvard T.H. Chan School of Public Health, Harvard University, Boston, MA, USA
| | - Stephen F Schaffner
- Broad Institute of Harvard and MIT, Cambridge, MA, USA
- Department of Immunology and Infectious Diseases, Harvard T.H. Chan School of Public Health, Harvard University, Boston, MA, USA
- Department of Organismic and Evolutionary Biology, Harvard University, Cambridge, MA, USA
| | - Daniel J Park
- Broad Institute of Harvard and MIT, Cambridge, MA, USA
| | - Aida S Badiane
- Centre International de recherche, de formation en Génomique Appliquée et de Surveillance Sanitaire (CIGASS), Dakar, Senegal
| | - Andres Colubri
- Broad Institute of Harvard and MIT, Cambridge, MA, USA
- University of Massachusetts Medical School, Worcester, MA, USA
| | - Mouhamadou Ndiaye
- Centre International de recherche, de formation en Génomique Appliquée et de Surveillance Sanitaire (CIGASS), Dakar, Senegal
| | - Ngayo Sy
- Service de Lutte Anti Parasitaire, Thies, Senegal
| | - Pardis C Sabeti
- Broad Institute of Harvard and MIT, Cambridge, MA, USA
- Department of Immunology and Infectious Diseases, Harvard T.H. Chan School of Public Health, Harvard University, Boston, MA, USA
- Department of Organismic and Evolutionary Biology, Harvard University, Cambridge, MA, USA
- Howard Hughes Medical Institute, Chevy Chase, MD, USA
| | - Daouda Ndiaye
- Centre International de recherche, de formation en Génomique Appliquée et de Surveillance Sanitaire (CIGASS), Dakar, Senegal
| | - Katherine J Siddle
- Broad Institute of Harvard and MIT, Cambridge, MA, USA
- Department of Molecular Microbiology and Immunology, Brown University, Providence, RI, USA
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El Hadji Ibrahima N, Diatta G, Adama Zan D, Bassene H, Sokhna C, Parola P. Quantitative Polymerase Chain Reaction from Malaria Rapid Diagnostic Tests to Detect Borrelia crocidurae, the Agent of Tick-Borne Relapsing Fever, in Febrile Patients in Senegal. Am J Trop Med Hyg 2023; 108:968-976. [PMID: 36913922 PMCID: PMC10160891 DOI: 10.4269/ajtmh.22-0342] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/20/2022] [Accepted: 10/29/2022] [Indexed: 03/14/2023] Open
Abstract
In endemic malaria areas, Plasmodium is currently diagnosed mainly through the use of rapid diagnostic tests (RDTs). However, in Senegal, many causes of fever remain unknown. Tick-borne relapsing fever, an often-neglected public health problem, is the main cause of consultation for acute febrile illness after malaria and flu in rural areas. Our objective was to test the feasibility of extracting and amplifying DNA fragments by quantitative polymerase chain reaction (qPCR) from malaria-negative RDTs for Plasmodium falciparum (malaria Neg RDTs P.f) to detect Borrelia spp. and other bacteria. Between January and December 2019, malaria Neg RDTs P.f were collected on a quarterly basis in 12 health facilities in four regions of Senegal. The DNA extracted from the malaria Neg RDTs P.f was tested using qPCR and the results were confirmed by standard PCR and sequencing. Only Borrelia crocidurae DNA was detected in 7.22% (159/2,202) of RDTs. The prevalence of B. crocidurae DNA was higher in July (16.47%, 43/261) and August (11.21%, 50/446). The annual prevalence was 9.2% (47/512) and 5.0% (12/241) in Ngayokhem and Nema-Nding, respectively, health facilities in the Fatick region. Our study confirms that B. crocidurae infection is a frequent cause of fever in Senegal, with a high prevalence of cases in health facilities in the regions of Fatick and Kaffrine. Malaria Neg RDTs P.f are potentially a good source of pathogen sampling for the molecular identification of other causes of fever of unknown origin, even in the most remote areas.
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Affiliation(s)
- Ndiaye El Hadji Ibrahima
- Aix Marseille Univ, Institut de Recherche pour le Développement (IRD), APHM, SSA, Vecteurs–Infections Tropicales et Méditerranéennes (VITROME), Marseille, France
- Institut Hospitalo-Universitaire (IHU) Méditerranée Infection, Marseille, France
- VITROME, IRD UMR 257, Campus International IRD-UCAD Hann, Dakar, Sénégal
| | - Georges Diatta
- VITROME, IRD UMR 257, Campus International IRD-UCAD Hann, Dakar, Sénégal
| | - Diarra Adama Zan
- Aix Marseille Univ, Institut de Recherche pour le Développement (IRD), APHM, SSA, Vecteurs–Infections Tropicales et Méditerranéennes (VITROME), Marseille, France
- Institut Hospitalo-Universitaire (IHU) Méditerranée Infection, Marseille, France
| | - Hubert Bassene
- VITROME, IRD UMR 257, Campus International IRD-UCAD Hann, Dakar, Sénégal
| | - Cheikh Sokhna
- Institut Hospitalo-Universitaire (IHU) Méditerranée Infection, Marseille, France
- VITROME, IRD UMR 257, Campus International IRD-UCAD Hann, Dakar, Sénégal
| | - Philippe Parola
- Aix Marseille Univ, Institut de Recherche pour le Développement (IRD), APHM, SSA, Vecteurs–Infections Tropicales et Méditerranéennes (VITROME), Marseille, France
- Institut Hospitalo-Universitaire (IHU) Méditerranée Infection, Marseille, France
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Niang K, Fall A, Ndiaye S, Sarr M, Ba K, Masquelier B. Enhancing the value of death registration with verbal autopsy data: a pilot study in the Senegalese urban population in 2019. Arch Public Health 2023; 81:45. [PMID: 36991465 DOI: 10.1186/s13690-023-01067-6] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/29/2022] [Accepted: 03/20/2023] [Indexed: 03/31/2023] Open
Abstract
BACKGROUND There is no source of data on causes of death in Senegal that covers both community and hospital deaths. Yet the death registration system in the Dakar region is relatively complete (>80%) and could be expanded to provide information on the diseases and injuries that led to death. METHODS In this pilot study, we recorded all deaths that occurred over 2 months and were reported in the 72 civil registration offices in the Dakar region. We selected the deaths of residents of the region and administered a verbal autopsy to a relative of the deceased to identify the underlying causes of death. Causes of death were assigned using the InterVA5 model. RESULTS The age structure of deaths registered at the civil registry differed from that of the census, with a proportion of infant deaths about twice as high as in the census. The main causes of death were prematurity and obstetric asphyxia in newborns. Meningitis and encephalitis, severe malnutrition, and acute respiratory infections were the leading causes from 1 month to 15 years of age. Cardiovascular diseases accounted for 27% of deaths in adults aged 15-64 and 45% of deaths among adults above age 65, while neoplasms accounted for 20% and 12% of deaths in these two age groups, respectively. CONCLUSIONS This study demonstrates that the epidemiological transition is at an advanced stage in urban areas of Dakar, and underlines the importance of conducting regular studies based on verbal autopsies of deaths reported in civil registration offices.
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Affiliation(s)
- Khadim Niang
- Department of Public Health and Social Medicine, University of Gaston Berger, Saint-Louis, Senegal
| | - Atoumane Fall
- Agence Nationale de la Statistique et de la Démographie (ANSD), Dakar, Senegal
| | - Samba Ndiaye
- Agence Nationale de la Statistique et de la Démographie (ANSD), Dakar, Senegal
| | - Maguette Sarr
- Agence Nationale de la Statistique et de la Démographie (ANSD), Dakar, Senegal
| | - Khady Ba
- Agence Nationale de la Statistique et de la Démographie (ANSD), Dakar, Senegal
| | - Bruno Masquelier
- Center for Demographic Research, Louvain University, Louvain-la-Neuve, Belgium.
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Tairou F, Diallo A, Sy O, Kone A, Manga IA, Sylla K, Lelo S, Fall CB, Sow D, Ndiaye M, Faye B, Tine RCK. Malaria-associated risk factors among adolescents living in areas with persistent transmission in Senegal: a case-control study. Malar J 2022; 21:193. [PMID: 35725475 PMCID: PMC9208171 DOI: 10.1186/s12936-022-04212-8] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/13/2021] [Accepted: 06/03/2022] [Indexed: 11/10/2022] Open
Abstract
BACKGROUND In Senegal, malaria morbidity has sharply decreased over these past years. However, malaria epidemiology remains heterogeneous with persistent transmission in the southeastern part of the country and many cases among older children and adolescents. Little is known about factors associated with clinical malaria among this group. A better understanding of malaria transmission among this newly emerging vulnerable group will guide future interventions targeting this population group. This study aimed to identify factors associated with clinical malaria among adolescents in Senegal. METHODS A case-control study was conducted from November to December 2020 in four health posts located in the Saraya district. Cases were defined as adolescents (10-19 years) with an uncomplicated malaria episode with fever (temperature > 37.5°) or a history of fever and positive malaria rapid diagnostic test (RDT). Controls were from the same age group, living in the neighbourhood of the case, presenting a negative RDT. A standardized, pre-tested questionnaire was administered to each study participant followed by a home visit to assess the participant's living conditions. Factors associated with clinical malaria were assessed using stepwise logistic regression analysis. RESULTS In total, 492 individuals were recruited (246 cases and 246 controls). In a multivariate analysis, factors associated with clinical malaria included non-use of long-lasting insecticidal net (LLIN) (aOR = 2.65; 95% CI 1.58-4.45), non-use of other preventive measures (aOR = 2.51; 95% CI 1.53-4.11) and indoor sleeping (aOR = 3.22; 95% CI 1.66-6.23). Protective factors included 15-19 years of age (aOR = 0.38; 95% CI 0.23-0.62), absence of stagnant water around the house (aOR = 0.27; 95% CI 0.16-0.44), having a female as head of household (aOR = 0.47; 95% CI 0.25-0.90), occupation such as apprentice (OR = 0.24; 95% CI 0.11-0.52). CONCLUSIONS The study revealed that environmental factors and non-use of malaria preventive measures are the main determinants of malaria transmission among adolescents living in areas with persistent malaria transmission in Senegal. Strategies aimed at improving disease awareness and access to healthcare interventions, such as LLINs, are needed to improve malaria control and prevention among these vulnerable groups.
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Affiliation(s)
- Fassiatou Tairou
- Department of Medical Parasitology, University Cheikh Anta Diop of Dakar, Dakar, Senegal.
| | | | - Ousmane Sy
- Department of Medical Parasitology, University Cheikh Anta Diop of Dakar, Dakar, Senegal
| | - Aminatou Kone
- Department of Medical Parasitology, University Cheikh Anta Diop of Dakar, Dakar, Senegal.,Malaria Research and Training Center, University of Bamako, Bamako, Mali
| | - Isaac Akhenaton Manga
- Department of Medical Parasitology, University Cheikh Anta Diop of Dakar, Dakar, Senegal
| | - Khadim Sylla
- Department of Medical Parasitology, University Cheikh Anta Diop of Dakar, Dakar, Senegal
| | - Souleye Lelo
- Department of Medical Parasitology, University Cheikh Anta Diop of Dakar, Dakar, Senegal
| | - Cheikh Binetou Fall
- Department of Medical Parasitology, University Cheikh Anta Diop of Dakar, Dakar, Senegal
| | - Doudou Sow
- Department of Medical Parasitology, University Cheikh Anta Diop of Dakar, Dakar, Senegal
| | - Magatte Ndiaye
- Department of Medical Parasitology, University Cheikh Anta Diop of Dakar, Dakar, Senegal
| | - Babacar Faye
- Department of Medical Parasitology, University Cheikh Anta Diop of Dakar, Dakar, Senegal
| | - Roger C K Tine
- Department of Medical Parasitology, University Cheikh Anta Diop of Dakar, Dakar, Senegal
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Elmardi KA, Adam I, Malik EM, Kafy HT, Abdin MS, Kleinschmidt I, Kremers S. Impact of malaria control interventions on malaria infection and anaemia in areas with irrigated schemes: a cross-sectional population-based study in Sudan. BMC Infect Dis 2021; 21:1248. [PMID: 34906083 PMCID: PMC8670187 DOI: 10.1186/s12879-021-06929-4] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/14/2021] [Accepted: 12/01/2021] [Indexed: 11/29/2022] Open
Abstract
Background While the overall burden of malaria is still high, the global technical strategy for malaria advocates for two sets of interventions: vector control-based prevention and diagnosis and prompt effective treatment of malaria cases. This study aimed to assess the performance of malaria interventions on malaria infection and anaemia in irrigated areas in Sudan. Methods Based on the Sudan 2016 national malaria indicator survey, data for two states (Gezira and Sennar), characterized by large-irrigated schemes, were analysed. Four community-level malaria interventions were used as contextual variables: utilization of malaria diagnosis, utilization of Artemisinin-based combination therapy (ACT), utilization of long-lasting insecticidal nets (LLINs) and coverage with indoor residual spraying (IRS). Association between these interventions and two outcomes: malaria infection and anaemia, was assessed separately. Malaria infection was assessed in all age groups while anaemia was assessed in children under 5 years. Multilevel multiple logistic regression analysis were conducted. Results Among 4478 individuals involved in this study distributed over 47 clusters, the overall malaria infection rate was 3.0% and 56.5% of the children under 5 years (total = 322) were anaemic. Except for IRS coverage (69.6%), the average utilization of interventions was relatively low: 52.3% for utilization of diagnosis, 33.0% for utilization of ACTs and 18.6% for LLINs utilization. The multi-level multiple logistic regression model showed that only IRS coverage was associated with malaria infection (Odds ratio 0.83 per 10% coverage, 95%Confidence Interval (95%CI) 0.74–0.94, p = 0.003) indicating that a higher level of IRS coverage was associated with less malaria infection. Anaemia was not associated with any intervention (all p values larger than 0.1). Conclusions Malaria transmission in Gezira and Sennar areas is low. IRS, with insecticide to which vectors are susceptible, is an effective malaria control intervention in irrigated schemes. Community utilization of other interventions was not associated with malaria infection in this study. This may be due to the low utilization of these interventions. However, individual use of LLINs provide personal protection. This study failed to establish an association between anaemia and malaria control interventions in low transmission areas. The higher level of malaria infection in urban areas is a cause for concern.
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Affiliation(s)
- Khalid Abdelmutalab Elmardi
- Health Information, Monitoring and Evaluation and Evidence Department, Federal Ministry of Health, Khartoum, Sudan. .,Department of Health Promotion, Faculty of Health, Medicine and Life Sciences, NUTRIM School of Nutrition and Translational Research in Metabolism, Maastricht, The Netherlands.
| | - Ishag Adam
- Department of Obstetrics and Gynecology, Unaizah College of Medicine and Medical Sciences, Qassim University, Unaizah, Saudi Arabia
| | | | - Hmooda Toto Kafy
- Directorate General of Primary Health Care, Federal Ministry of Health, Khartoum, Sudan
| | - Mogahid Sheikheldien Abdin
- Health Information, Monitoring and Evaluation and Evidence Department, Federal Ministry of Health, Khartoum, Sudan
| | - Immo Kleinschmidt
- MRC International Statistics and Epidemiology Group, Departments of Infectious Disease Epidemiology, London School of Hygiene and Tropical Medicine, London, UK.,Wits Research Institute for Malaria, School of Pathology, Faculty of Health Sciences, University of the Witwatersrand, Johannesburg, South Africa.,Southern African Development Community Malaria Elimination Eight Secretariat, Windhoek, Namibia
| | - Stef Kremers
- Department of Health Promotion, Faculty of Health, Medicine and Life Sciences, NUTRIM School of Nutrition and Translational Research in Metabolism, Maastricht, The Netherlands
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9
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Genomic investigation of a dengue virus outbreak in Thiès, Senegal, in 2018. Sci Rep 2021; 11:10321. [PMID: 33990632 PMCID: PMC8121849 DOI: 10.1038/s41598-021-89070-1] [Citation(s) in RCA: 15] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/19/2020] [Accepted: 03/16/2021] [Indexed: 12/23/2022] Open
Abstract
Dengue virus is a major and rapidly growing public health concern in tropic and subtropic regions across the globe. In late 2018, Senegal experienced its largest dengue virus outbreak to date, covering several regions. However, little is known about the genetic diversity of dengue virus (DENV) in Senegal. Here we report complete viral genomes from 17 previously undetected DENV cases from the city of Thiès. In total we identified 19 cases of DENV in a cohort of 198 individuals with fever collected in October and November 2018. We detected 3 co-circulating serotypes; DENV 3 was the most frequent accounting for 11/17 sequences (65%), 4 (23%) were DENV2 and 2 (12%) were DENV1. Sequences were most similar to recent sequences from West Africa, suggesting ongoing local circulation of viral populations; however, detailed inference is limited by the scarcity of available genomic data. We did not find clear associations with reported clinical signs or symptoms, highlighting the importance of testing for diagnosing febrile diseases. Overall, these findings expand the known range of DENV in Senegal, and underscore the need for better genomic characterization of DENV in West Africa.
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10
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Sy M, Badiane AS, Deme AB, Gaye A, Ndiaye T, Fall FB, Siddle KJ, Dieye B, Ndiaye YD, Diallo MA, Diongue K, Seck MC, Ndiaye IM, Cissé M, Gueye AB, Sène D, Dieye Y, Souané T, MacInnis B, Volkman SK, Wirth DF, Ndiaye D. Genomic investigation of atypical malaria cases in Kanel, northern Senegal. Malar J 2021; 20:103. [PMID: 33608006 PMCID: PMC7893743 DOI: 10.1186/s12936-021-03637-x] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/14/2020] [Accepted: 02/09/2021] [Indexed: 11/10/2022] Open
Abstract
BACKGROUND The diagnosis of malaria cases in regions where the malaria burden has decreased significantly and prevalence is very low is more challenging, in part because of reduced clinical presumption of malaria. The appearance of a cluster of malaria cases with atypical symptoms in Mbounguiel, a village in northern Senegal where malaria transmission is low, in September 2018 exemplifies this scenario. The collaboration between the National Malaria Control Programme (NMCP) at the Senegal Ministry of Health and the Laboratory of Parasitology and Mycology at Cheikh Anta Diop University worked together to evaluate this cluster of malaria cases using molecular and serological tools. METHODS Malaria cases were diagnosed primarily by rapid diagnostic test (RDT), and confirmed by photo-induced electron transfer-polymerase chain reaction (PET-PCR). 24 single nucleotide polymorphisms (SNPs) barcoding was used for Plasmodium falciparum genotyping. Unbiased metagenomic sequencing and Luminex-based multi-pathogen antibody and antigen profiling were used to assess exposure to other pathogens. RESULTS Nine patients, of 15 suspected cases, were evaluated, and all nine samples were found to be positive for P. falciparum only. The 24 SNPs molecular barcode showed the predominance of polygenomic infections, with identifiable strains being different from one another. All patients tested positive for the P. falciparum antigens. No other pathogenic infection was detected by either the serological panel or metagenomic sequencing. CONCLUSIONS This work, undertaken locally within Senegal as a collaboration between the NMCP and a research laboratory at University of Cheikh Anta Diop (UCAD) revealed that a cluster of malaria cases were caused by different strains of P. falciparum. The public health response in real time demonstrates the value of local molecular and genomics capacity in affected countries for disease control and elimination.
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Affiliation(s)
- Mouhamad Sy
- Laboratory of Parasitology and Mycology, Aristide le Dantec Hospital, Cheikh Anta Diop University, Dakar, Senegal.
| | - Aida Sadikh Badiane
- Laboratory of Parasitology and Mycology, Aristide le Dantec Hospital, Cheikh Anta Diop University, Dakar, Senegal
| | - Awa Bineta Deme
- Laboratory of Parasitology and Mycology, Aristide le Dantec Hospital, Cheikh Anta Diop University, Dakar, Senegal
| | - Amy Gaye
- Laboratory of Parasitology and Mycology, Aristide le Dantec Hospital, Cheikh Anta Diop University, Dakar, Senegal
| | - Tolla Ndiaye
- Laboratory of Parasitology and Mycology, Aristide le Dantec Hospital, Cheikh Anta Diop University, Dakar, Senegal
| | - Fatou Ba Fall
- Senegal National Malaria Control Programme, Dakar, Senegal
| | | | - Baba Dieye
- Laboratory of Parasitology and Mycology, Aristide le Dantec Hospital, Cheikh Anta Diop University, Dakar, Senegal
| | - Yaye Die Ndiaye
- Laboratory of Parasitology and Mycology, Aristide le Dantec Hospital, Cheikh Anta Diop University, Dakar, Senegal
| | - Mamadou Alpha Diallo
- Laboratory of Parasitology and Mycology, Aristide le Dantec Hospital, Cheikh Anta Diop University, Dakar, Senegal
| | - Khadim Diongue
- Laboratory of Parasitology and Mycology, Aristide le Dantec Hospital, Cheikh Anta Diop University, Dakar, Senegal
| | - Mame Cheikh Seck
- Laboratory of Parasitology and Mycology, Aristide le Dantec Hospital, Cheikh Anta Diop University, Dakar, Senegal
| | - Ibrahima Mbaye Ndiaye
- Laboratory of Parasitology and Mycology, Aristide le Dantec Hospital, Cheikh Anta Diop University, Dakar, Senegal
| | | | | | - Doudou Sène
- Senegal National Malaria Control Programme, Dakar, Senegal
| | - Yakou Dieye
- Malaria Control and Evaluation Partnership in Africa PATH-MACEPA, Dakar, Senegal
| | - Tamba Souané
- Malaria Control and Evaluation Partnership in Africa PATH-MACEPA, Dakar, Senegal
| | - Bronwyn MacInnis
- The Broad Institute of MIT and Harvard, Cambridge, MA, USA
- Department of Immunology and Infectious Diseases, Harvard T. H. Chan School of Public Health, Boston, MA, USA
| | - Sarah K Volkman
- The Broad Institute of MIT and Harvard, Cambridge, MA, USA
- Department of Immunology and Infectious Diseases, Harvard T. H. Chan School of Public Health, Boston, MA, USA
- College of Natural, Behavioral, and Health Sciences, Simmons University, Boston, MA, USA
| | - Dyann F Wirth
- The Broad Institute of MIT and Harvard, Cambridge, MA, USA
- Department of Immunology and Infectious Diseases, Harvard T. H. Chan School of Public Health, Boston, MA, USA
| | - Daouda Ndiaye
- Laboratory of Parasitology and Mycology, Aristide le Dantec Hospital, Cheikh Anta Diop University, Dakar, Senegal
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Gildas Boris H, Idrissa D, Marie Louise S, Cheikh T, Aliou BM, Fatoumata DS, Rebecca G, Raymond B, Diamilatou T, Vincent R, Oumar F, Abdoulaye S, Muriel V. Identification of Pathogens Potentially Associated with Non-Malarial Fever in Children: A Pilot Study in Peri-Urban Dakar, Senegal. Am J Trop Med Hyg 2021; 104:1335-1341. [PMID: 33556036 DOI: 10.4269/ajtmh.19-0963] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/24/2019] [Accepted: 12/07/2020] [Indexed: 12/15/2022] Open
Abstract
Fever is one of the most common reasons for pediatric consultation in Africa. Malaria incidence has now dropped considerably, yet etiologies of non-malarial febrile diseases are poorly documented. This pilot study aimed to 1) identify pathogens potentially associated with non-malarial fever in children younger than 10 years in the suburbs of Dakar and 2) describe the epidemiological characteristics of these patients. During the study period, all eligible children (< 10 years of age, body temperature ≥ 38°C, negative result for the malaria rapid diagnostic test, living in Guediawaye/Pikine for the previous four calendar months, not receiving any anti-infectious treatment since the onset of fever, and with parent's consent to participate) presenting to the health post in Medina Gounass located in Guediawaye on Mondays and Fridays were included. In total, 106 children participated in the study, and PCR from nasopharyngeal swabs, hemoculture, C-reactive protein, blood cell counts, and quantitative buffy coat from blood samples and coproculture from stool samples were performed. In 70 (66%) children, at least one pathogen was isolated. Viruses were identified in 55 children, most commonly enteroviruses, rhinoviruses, and adenoviruses, and dengue virus was identified in three children. Only five children had bacterial infections, and 10 had bacterial and viral coinfections. Ninety-seven children (92%) received prescription for antibiotics. Many strains of bacteria were found to be resistant to several antibiotics. Despite limitations, this pilot study showed that pathogens potentially associated with non-malarial fever in children younger than 10 years near Dakar were predominantly viruses, most commonly upper respiratory infections, although bacteria accounted for a small proportion.
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Affiliation(s)
- Hedible Gildas Boris
- 1Unité d'Epidémiologie des Maladies Infectieuses, Institut Pasteur, Dakar, Senegal
| | - Dieng Idrissa
- 2Pôle de Virologie, Institut Pasteur, Dakar, Senegal
| | - Senghor Marie Louise
- 1Unité d'Epidémiologie des Maladies Infectieuses, Institut Pasteur, Dakar, Senegal
| | - Talla Cheikh
- 1Unité d'Epidémiologie des Maladies Infectieuses, Institut Pasteur, Dakar, Senegal
| | - Barry Mamadou Aliou
- 1Unité d'Epidémiologie des Maladies Infectieuses, Institut Pasteur, Dakar, Senegal
| | - Diène Sarr Fatoumata
- 1Unité d'Epidémiologie des Maladies Infectieuses, Institut Pasteur, Dakar, Senegal
| | - Grant Rebecca
- 3Unité d'épidémiologie des Maladies émergentes, Institut Pasteur, Paris, France
| | - Bercion Raymond
- 4Laboratoire de Biologie Médicale, Institut Pasteur, Dakar, Senegal
| | - Thiam Diamilatou
- 1Unité d'Epidémiologie des Maladies Infectieuses, Institut Pasteur, Dakar, Senegal
| | | | - Faye Oumar
- 2Pôle de Virologie, Institut Pasteur, Dakar, Senegal
| | - Seck Abdoulaye
- 4Laboratoire de Biologie Médicale, Institut Pasteur, Dakar, Senegal.,6Faculté de Médecine, de Pharmacie et d'Odontologie, UCAD, Dakar, Senegal
| | - Vray Muriel
- 1Unité d'Epidémiologie des Maladies Infectieuses, Institut Pasteur, Dakar, Senegal.,3Unité d'épidémiologie des Maladies émergentes, Institut Pasteur, Paris, France.,7INSERM, France
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12
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Rossi P, Villar P. Private health investments under competing risks: Evidence from malaria control in Senegal. JOURNAL OF HEALTH ECONOMICS 2020; 73:102330. [PMID: 32711291 DOI: 10.1016/j.jhealeco.2020.102330] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/12/2019] [Revised: 04/09/2020] [Accepted: 04/22/2020] [Indexed: 06/11/2023]
Abstract
This study exploits the introduction of high subsidies for anti-malaria products in Senegal in 2009 to investigate whether malaria prevents parents from investing in child health. A simple model of health investments under competing mortality risks predicts that private expenses to fight malaria and other diseases should increase in response to anti-malaria public interventions. We test and validate this prediction using original panel data from a household expenditure survey combined with geographical information on malaria prevalence. We find that health expenditures in malarious regions catch up with non-malarious regions. The same result holds for parental health-seeking behavior against other diseases like diarrhea. These patterns cannot be explained by differential trends between regions. Our results suggest that behavioral responses to anti-malaria campaigns magnify their impact on all-cause mortality for children.
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Affiliation(s)
- Pauline Rossi
- University of Amsterdam, office E6.21, Roeterstraat 11, 1018WB Amsterdam, Netherlands.
| | - Paola Villar
- University of Namur (UNamur), CRED, office 633, Remparts de la Vierge 8, 5000 Namur, Belgium.
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13
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Sagna AB, Kassié D, Couvray A, Adja AM, Hermann E, Riveau G, Salem G, Fournet F, Remoue F. Spatial Assessment of Contact Between Humans and Anopheles and Aedes Mosquitoes in a Medium-Sized African Urban Setting, Using Salivary Antibody-Based Biomarkers. J Infect Dis 2020; 220:1199-1208. [PMID: 31152664 DOI: 10.1093/infdis/jiz289] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/06/2019] [Accepted: 05/30/2019] [Indexed: 11/14/2022] Open
Abstract
BACKGROUND Anarchic and poorly controlled urbanization led to an increased risk of mosquito-borne diseases (MBD) in many African cities. Here, we evaluate the spatial heterogeneity of human exposure to malaria and arboviral disease vectors in an urban area of northern Senegal, using antibody-based biomarkers of exposure to Anopheles and Aedes mosquito bites. METHODS A cross-sectional study was undertaken during the rainy season of 2014 in 4 neighborhoods of Saint-Louis, a city in northern Senegal. Among children aged 6-59 months in each neighborhood, the dried blood spot technique was used to evaluate immunoglobulin G (IgG) responses to both gSG6-P1 (Anopheles) and Nterm-34-kDa (Aedes) salivary peptides as validated biomarkers of respective mosquito bite exposure. RESULTS IgG response levels to gSG6-P1 and Nterm-34-kDa salivary peptides varied significantly between the 4 neighborhoods (P < .0001). The level of exposure to Aedes bites also varied according to household access to sanitation services (P = .027), whereas that of exposure to Anopheles bites varied according to insecticide-treated bed net use (P = .006). In addition, spatial clusters of high contact between humans and mosquitoes were identified inside 3 neighborhoods. CONCLUSIONS Antibody-based biomarkers of exposure to Anopheles and Aedes mosquito bites could be helpful tools for evaluating the heterogeneity of exposure to malaria and arboviral disease vectors by national control programs.
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Affiliation(s)
- André B Sagna
- MIVEGEC, University of Montpellier, CNRS, IRD
- Institut Pierre Richet/Institut National de Santé Publique, Bouaké, Côte d'Ivoire
- Biomedical Research Center Espoir Pour La Santé, Saint-Louis, Sénégal
| | - Daouda Kassié
- ASTRE, University of Montpellier, CIRAD, INRA, Montpellier
- Institut de Recherche en Sciences de la Santé, Bobo-Dioulasso, Burkina Faso
| | | | - Akré Maurice Adja
- Institut Pierre Richet/Institut National de Santé Publique, Bouaké, Côte d'Ivoire
| | - Emmanuel Hermann
- CIIL, Institut Pasteur de Lille, University of Lille, CNRS UMR, Inserm, Lille, France
| | - Gilles Riveau
- CIIL, Institut Pasteur de Lille, University of Lille, CNRS UMR, Inserm, Lille, France
- Biomedical Research Center Espoir Pour La Santé, Saint-Louis, Sénégal
| | - Gérard Salem
- CEPED, University of Paris Descartes, IRD, Paris
| | - Florence Fournet
- MIVEGEC, University of Montpellier, CNRS, IRD
- Institut de Recherche en Sciences de la Santé, Bobo-Dioulasso, Burkina Faso
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14
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Diallo MA, Badiane AS, Diongue K, Sakandé L, Ndiaye M, Seck MC, Ndiaye D. A twenty-eight-year laboratory-based retrospective trend analysis of malaria in Dakar, Senegal. PLoS One 2020; 15:e0231587. [PMID: 32413069 PMCID: PMC7228107 DOI: 10.1371/journal.pone.0231587] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/31/2019] [Accepted: 03/27/2020] [Indexed: 11/18/2022] Open
Abstract
INTRODUCTION Health facility-based records offer a rich source of information to understand trends and changes in malaria cases over time. This study is aimed at determining the changes in malaria occurrence over the last 28 years, from 1989 to 2016 in Dakar, Senegal. METHODS Laboratory suspected and confirmed malaria records from 1989 to 2016 were reviewed from the laboratory registers of the Laboratory of Parasitology and Mycology of Aristide Le Dantec Hospital. Interrupted time series (ITS) analysis was used to estimate the changes by comparing malaria cases post-intervention (2006-2016) with that of the pre-intervention (1989-2005) period. RESULTS A total of 5,876 laboratory confirmed malaria cases were reported out of 29,852 tested cases, with total slide positivity rate (SPR) of 19.7%. Malaria case counts exhibited a fluctuating trend with major peaks occurring in the years 1995 and 2003 with SPR of 42.3% and 42.5%, respectively. Overall, a remarkable decline in the total number of laboratory confirmed malaria cases was observed over the last 28 years. P. falciparum was almost the only reported species, accounting for 99.98% of cases. The highest SPR was observed in the age group of under five years during the pre-intervention period while this shifted to the age group of 6-15 years old for the subsequent years. Two major malaria peak seasons were observed: one in September during the pre-intervention period and the other in November for the post-intervention period. The ITS analysis showed a dramatic decline of 83.6% in SPR following the scale-up of interventions in 2006. CONCLUSION A remarkable decline in laboratory confirmed malaria cases in Dakar over 28 years was observed. The period of rapid decline in malaria SPR coincided with the scale-up in interventions beginning in 2006 with the introduction of ACTs, followed by the widespread introduction in 2008 of bed nets treated with insecticides. Robust surveillance data should be maintained in the context of malaria elimination efforts.
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Affiliation(s)
- Mamadou Alpha Diallo
- Department of Parasitology, Cheikh Anta Diop University, Dakar, Senegal
- * E-mail:
| | | | - Khadim Diongue
- Department of Parasitology, Cheikh Anta Diop University, Dakar, Senegal
| | - Linda Sakandé
- Department of Parasitology, Cheikh Anta Diop University, Dakar, Senegal
| | - Mouhamadou Ndiaye
- Department of Parasitology, Cheikh Anta Diop University, Dakar, Senegal
| | - Mame Cheikh Seck
- Department of Parasitology, Cheikh Anta Diop University, Dakar, Senegal
| | - Daouda Ndiaye
- Department of Parasitology, Cheikh Anta Diop University, Dakar, Senegal
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15
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Ashton RA, Prosnitz D, Andrada A, Herrera S, Yé Y. Evaluating malaria programmes in moderate- and low-transmission settings: practical ways to generate robust evidence. Malar J 2020; 19:75. [PMID: 32070357 PMCID: PMC7027277 DOI: 10.1186/s12936-020-03158-z] [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: 12/05/2019] [Accepted: 02/09/2020] [Indexed: 12/15/2022] Open
Abstract
BACKGROUND Many countries have made substantial progress in scaling-up and sustaining malaria intervention coverage, leading to more focalized and heterogeneous transmission in many settings. Evaluation provides valuable information for programmes to understand if interventions have been implemented as planned and with quality, if the programme had the intended impact on malaria burden, and to guide programmatic decision-making. Low-, moderate-, and heterogeneous-transmission settings present unique evaluation challenges because of dynamic and targeted intervention strategies. This paper provides illustration of evaluation approaches and methodologies for these transmission settings, and suggests how to answer evaluation questions specific to the local context. METHODS The Roll Back Malaria Monitoring and Evaluation Reference Group formed a task force in October 2017 to lead development of this framework. The task force includes representatives from National Malaria Programmes, funding agencies, and malaria research and implementing partners. The framework builds on existing guidance for process and outcome evaluations and impact evaluations specifically in high transmission settings. RESULTS The theory of change describes how evaluation questions asked by national malaria programmes in different contexts influence evaluation design. The transmission setting, existing stratification, and data quality and availability are also key considerations. The framework is intended for adaption by countries to their local context, and use for evaluation at sub-national level. Confirmed malaria incidence is recommended as the primary impact indicator due to its sensitivity to detect changes in low-transmission settings. It is expected that process evaluations provide sufficient evidence for programme monitoring and improvement, while impact evaluations are needed following adoption of new mixes of interventions, operational strategies, tools or policies, particularly in contexts of changing malaria epidemiology. Impact evaluations in low-, moderate-, or heterogeneous-transmission settings will likely use plausibility designs, and methods highlighted by the framework include interrupted time series, district-level dose-response analyses, and constructed control methods. Triangulating multiple data sources and analyses is important to strengthen the plausibility argument. CONCLUSIONS This framework provides a structure to assist national malaria programmes and partners to design evaluations in low-, moderate- or heterogeneous-transmission settings. Emphasizing a continuous cycle along the causal pathway linking process evaluation to impact evaluation and then programmatic decision-making, the framework provides practical guidance in evaluation design, analysis, and interpretation to ensure that the evaluation meets national malaria programme priority questions and guides decision-making at national and sub-national levels.
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Affiliation(s)
- Ruth A Ashton
- MEASURE Evaluation, Center for Applied Malaria Research and Evaluation, Tulane School of Public Health and Tropical Medicine, Tulane University, 1440 Canal Street, Suite 2300, New Orleans, LA, USA.
| | | | | | - Samantha Herrera
- MEASURE Evaluation, ICF, Rockville, MD, USA.,Save the Children, Washington, DC, USA
| | - Yazoumé Yé
- MEASURE Evaluation, ICF, Rockville, MD, USA
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16
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Effect of Free Healthcare Policy for Children under Five Years Old on the Incidence of Reported Malaria Cases in Burkina Faso by Bayesian Modelling: "Not only the Ears but also the Head of the Hippopotamus". INTERNATIONAL JOURNAL OF ENVIRONMENTAL RESEARCH AND PUBLIC HEALTH 2020; 17:ijerph17020417. [PMID: 31936308 PMCID: PMC7014427 DOI: 10.3390/ijerph17020417] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 11/24/2019] [Revised: 12/24/2019] [Accepted: 01/03/2020] [Indexed: 02/02/2023]
Abstract
Burkina Faso has recently implemented an additional strategy, the free healthcare policy, to further improve maternal and child health. This policy targets children under five who bear the brunt of the malaria scourge. The effects of the free-of-charge healthcare were previously assessed in women but not in children. The present study aims at filling this gap by assessing the effect of this policy in children under five with a focus on the induced spatial and temporal changes in malaria morbidity. We used a Bayesian spatiotemporal negative binomial model to investigate the space–time variation in malaria incidence in relation to the implementation of the policy. The analysis relied on malaria routine surveillance data extracted from the national health data repository and spanning the period from January 2013 to December 2018. The model was adjusted for meteorological and contextual confounders. We found that the number of presumed and confirmed malaria cases per 1000 children per month increased between 2013 and 2018. We further found that the implementation of the free healthcare policy was significantly associated with a two-fold increase in the number of tested and confirmed malaria cases compared with the period before the policy rollout. This effect was, however, heterogeneous across the health districts. We attributed the rise in malaria incidence following the policy rollout to an increased use of health services combined with an increased availability of rapid tests and a higher compliance to the “test and treat” policy. The observed heterogeneity in the policy effect was attributed to parallel control interventions, some of which were rolled out at different paces and scales. Our findings call for a sustained and reinforced effort to test all suspected cases so that, alongside an improved case treatment, the true picture of the malaria scourge in children under five emerges clearly (see the hippopotamus almost entirely).
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17
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Amambua-Ngwa A, Jeffries D, Mwesigwa J, Seedy-Jawara A, Okebe J, Achan J, Drakeley C, Volkman S, D'Alessandro U. Long-distance transmission patterns modelled from SNP barcodes of Plasmodium falciparum infections in The Gambia. Sci Rep 2019; 9:13515. [PMID: 31534181 PMCID: PMC6751170 DOI: 10.1038/s41598-019-49991-4] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/08/2018] [Accepted: 08/12/2019] [Indexed: 02/04/2023] Open
Abstract
Malaria has declined significantly in The Gambia and determining transmission dynamics of Plasmodium falciparum can help targeting control interventions towards elimination. This can be inferred from genetic similarity between parasite isolates from different sites and timepoints. Here, we imposed a P. falciparum life cycle time on a genetic distance likelihood model to determine transmission paths from a 54 SNP barcode of 355 isolates. Samples were collected monthly during the 2013 malaria season from six pairs of villages spanning 300 km from western to eastern Gambia. There was spatial and temporal hierarchy in pairwise genetic relatedness, with the most similar barcodes from isolates within the same households and village. Constrained by travel data, the model detected 60 directional transmission events, with 27% paths linking persons from different regions. We identified 13 infected individuals (4.2% of those genotyped) responsible for 2 to 8 subsequent infections within their communities. These super-infectors were mostly from high transmission villages. When considering paths between isolates from the most distant regions (west vs east) and travel history, there were 3 transmission paths from eastern to western Gambia, all at the peak (October) of the malaria transmission season. No paths with known travel originated from the extreme west to east. Although more than half of all paths were within-village, parasite flow from east to west may contribute to maintain transmission in western Gambia, where malaria transmission is already low. Therefore, interrupting malaria transmission in western Gambia would require targeting eastern Gambia, where malaria prevalence is substantially higher, with intensified malaria interventions.
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Affiliation(s)
- Alfred Amambua-Ngwa
- Medical Research Council Unit The Gambia at London School of Hygiene and Tropical Medicine, Banjul, The Gambia.
| | - David Jeffries
- Medical Research Council Unit The Gambia at London School of Hygiene and Tropical Medicine, Banjul, The Gambia
| | - Julia Mwesigwa
- Medical Research Council Unit The Gambia at London School of Hygiene and Tropical Medicine, Banjul, The Gambia
| | - Aminata Seedy-Jawara
- Medical Research Council Unit The Gambia at London School of Hygiene and Tropical Medicine, Banjul, The Gambia
| | - Joseph Okebe
- Medical Research Council Unit The Gambia at London School of Hygiene and Tropical Medicine, Banjul, The Gambia
| | - Jane Achan
- Medical Research Council Unit The Gambia at London School of Hygiene and Tropical Medicine, Banjul, The Gambia
| | - Chris Drakeley
- London School of Hygiene and tropical Medicine, London, UK
| | - Sarah Volkman
- Harvard School of Public Health, Boston, Massachusetts, USA
| | - Umberto D'Alessandro
- Medical Research Council Unit The Gambia at London School of Hygiene and Tropical Medicine, Banjul, The Gambia.,London School of Hygiene and tropical Medicine, London, UK
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18
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Lechthaler F, Matthys B, Lechthaler-Felber G, Likwela JL, Mavoko HM, Rika JM, Mutombo MM, Ruckstuhl L, Barczyk J, Shargie E, Prytherch H, Lengeler C. Trends in reported malaria cases and the effects of malaria control in the Democratic Republic of the Congo. PLoS One 2019; 14:e0219853. [PMID: 31344062 PMCID: PMC6658057 DOI: 10.1371/journal.pone.0219853] [Citation(s) in RCA: 20] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/29/2019] [Accepted: 07/02/2019] [Indexed: 12/05/2022] Open
Abstract
Background Considerable upscaling of malaria control efforts have taken place over the last 15 years in the Democratic Republic of Congo, the country with the second highest malaria case load after Nigeria. Malaria control interventions have been strengthened in line with the Millenium Development Goals. We analysed the effects of these interventions on malaria cases at health facility level, using a retrospective trend analysis of malaria cases between 2005 and 2014. Data were collected from outpatient and laboratory registers based on a sample of 175 health facilities that represents all eco-epidemiological malaria settings across the country. Methods We applied a time series analysis to assess trends of suspected and confirmed malaria cases, by health province and for different age groups. A linear panel regression model controlled for non-malaria outpatient cases, rain fall, nightlight intensity, health province and time fixed effects, was used to examine the relationship between the interventions and malaria case occurrences, as well as test positivity rates. Results Overall, recorded suspected and confirmed malaria cases in the DRC have increased. The sharp increase in confirmed cases from 2010 coincides with the introduction of the new treatment policy and the resulting scale-up of diagnostic testing. Controlling for confounding factors, the introduction of rapid diagnostic tests (RDTs) was significantly associated with the number of tested and confirmed cases. The test positivity rate fluctuated around 40% without showing any trend. Conclusion The sharp increase in confirmed malaria cases from 2010 is unlikely to be due to a resurgence of malaria, but is clearly associated with improved diagnostic availability, mainly the introduction of RDTs. Before that, a great part of malaria cases were treated based on clinical suspicion. This finding points to a better detection of cases that potentially contributed to improved case management. Furthermore, the expansion of diagnostic testing along with the increase in confirmed cases implies that before 2010, cases were underreported, and that the accuracy of routine data to describe malaria incidence has improved.
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Affiliation(s)
- Filippo Lechthaler
- Swiss Centre for International Health, Swiss Tropical and Public Health Institute, Basel, Canton of Basel Stadt, Switzerland
- University of Basel, Basel, Canton of Basel Stadt, Switzerland
- School of Agricultural, Forest and Food Sciences, Bern University of Applied Sciences, Zollikofen, Canton of Bern, Switzerland
| | - Barbara Matthys
- Swiss Centre for International Health, Swiss Tropical and Public Health Institute, Basel, Canton of Basel Stadt, Switzerland
- University of Basel, Basel, Canton of Basel Stadt, Switzerland
- * E-mail:
| | - Giulia Lechthaler-Felber
- Faculty of Business and Economics, University of Basel, Basel, Canton of Basel Stadt, Switzerland
| | - Joris Losimba Likwela
- Soins de Santé en Milieu Rural (non-profit organization SANRU), Kinshasa, Democratic Republic of the Congo
| | - Hypolite Muhindo Mavoko
- Tropical Medicine Department, University of Kinshasa, Kinshasa, Democratic Republic of the Congo
| | - Junior Matangila Rika
- Tropical Medicine Department, University of Kinshasa, Kinshasa, Democratic Republic of the Congo
| | - Meschac Mutombo Mutombo
- National Malaria Control Program, Ministry of Health, Kinshasa, Democratic Republic of the Congo
| | - Laura Ruckstuhl
- University of Basel, Basel, Canton of Basel Stadt, Switzerland
- Epidemiology and Public Health Department, Swiss Tropical and Public Health Institute, Basel, Canton of Basel Stadt, Switzerland
| | - Joanna Barczyk
- The Global Fund to fight AIDS, Tuberculosis, and Malaria, Geneva, Canton of Geneva, Switzerland
| | - Estifanos Shargie
- The Global Fund to fight AIDS, Tuberculosis, and Malaria, Geneva, Canton of Geneva, Switzerland
| | - Helen Prytherch
- Swiss Centre for International Health, Swiss Tropical and Public Health Institute, Basel, Canton of Basel Stadt, Switzerland
- University of Basel, Basel, Canton of Basel Stadt, Switzerland
| | - Christian Lengeler
- University of Basel, Basel, Canton of Basel Stadt, Switzerland
- Epidemiology and Public Health Department, Swiss Tropical and Public Health Institute, Basel, Canton of Basel Stadt, Switzerland
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19
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Rowe AK. Assessing the Health Impact of Malaria Control Interventions in the MDG/Sustainable Development Goal Era: A New Generation of Impact Evaluations. Am J Trop Med Hyg 2019; 97:6-8. [PMID: 28990917 PMCID: PMC5619937 DOI: 10.4269/ajtmh.17-0509] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022] Open
Affiliation(s)
- Alexander K Rowe
- Malaria Branch, Division of Parasitic Diseases and Malaria, Centers for Disease Control and Prevention, Atlanta, Georgia
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20
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Mazigo E, Kidima W, Myamba J, Kweka EJ. The impact of Anopheles gambiae egg storage for mass rearing and production success. Malar J 2019; 18:52. [PMID: 30808356 PMCID: PMC6390356 DOI: 10.1186/s12936-019-2691-4] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/10/2018] [Accepted: 02/21/2019] [Indexed: 12/22/2022] Open
Abstract
BACKGROUND Mass rearing requires a large colony from which male individuals can be harvested for sterilization and release. Attention is needed when monitoring life parameters of the reared population, knowing that any variations within the target population would lead to mismatching between two populations. The aim of this study was to assess the impact of Anopheles gambiae sensu stricto (s.s.) egg storage on hatchability and life history traits. For each parameter, comparison was made between freshly laid and stored eggs in three densities (40, 80, 120 eggs). METHODS Anopheles gambiae s.s. freshly laid eggs were collected from the Tropical Pesticide Research Institute (TPRI) insectary. Eggs to be stored were kept at - 20 °C for 10 min and then transferred to refrigerators at 4 °C for intervals of 5, 10, 15, 20, and 25 days. After respective storage days, the eggs were transferred from refrigerators to ambient temperature of (25 ± 2) °C for 24 h and then placed in incubators for 24 h. Thereafter eggs were hatched. The egg hatchability, emerged larvae development, larvae survival and emerged adult sex ratios were monitored. RESULTS This study found that hatching rates decreased with increase in storage time. The difference was significant in eggs stored for 10 and 15 days (P < 0.05). There were no significant differences in hatching rates between An. gambiae eggs stored for 5 days and freshly hatched eggs (P > 0.05). Anopheles larvae development (L1 to pupae) was not significantly affected by storage time across all hatching densities. The study also found that larvae survival decreased with increase in egg storage time. However, there was no significant difference between larvae from freshly hatched eggs and those from eggs at 5 and 10 storage days (P > 0.05) but not for eggs stored for 15 days. Furthermore, there was a decrease in emerged adult males and increase in females relative to increased time of egg storage. The difference was significant (P < 0.05) at 15 storage days but not for eggs stored for 5 and 10 days (in triplicate densities). CONCLUSION From this study it was concluded that storing An. gambiae eggs at 4 °C and 48 ± 2% relative humidity (RH) for 5 days is the optimal condition and time that did not affect egg hatching rates, larval development and survivorship and emerged adult mosquito sex ratio.
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Affiliation(s)
- Ernest Mazigo
- Department of Zoology and Wildlife Conservation, College of Natural and Applied Sciences, University of Dar es Salaam, Dar es Salaam, Tanzania
| | - Winifrida Kidima
- Department of Zoology and Wildlife Conservation, College of Natural and Applied Sciences, University of Dar es Salaam, Dar es Salaam, Tanzania
| | - Joseph Myamba
- National Institute for Medical Research, Amani Medical Research Centre, P.O. Box 81, Muheza, Tanzania
| | - Eliningaya J Kweka
- Department of Medical Parasitology, School of Medicine, Catholic University of Health and Allied Sciences-Bugando, P.O. Box 1464, Mwanza, Tanzania. .,Division of Livestock and Human Disease Vector Control, Tropical Pesticides Research Institute, P.O.Box 3024, Arusha, Tanzania.
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21
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Kayentao K, Florey LS, Mihigo J, Doumbia A, Diallo A, Koné D, Doumbo O, Eckert E. Impact evaluation of malaria control interventions on morbidity and all-cause child mortality in Mali, 2000-2012. Malar J 2018; 17:424. [PMID: 30428880 PMCID: PMC6236933 DOI: 10.1186/s12936-018-2573-1] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/06/2018] [Accepted: 11/09/2018] [Indexed: 11/10/2022] Open
Abstract
BACKGROUND Major investments have been made since 2001, with intensification of malaria control interventions after 2006. Interventions included free distribution of insecticide-treated nets (ITN) to pregnant women and children under 5 years old, the introduction of artemisinin combination therapy (ACT) for malaria treatment, and indoor residual spraying of insecticides. Funders include the Government of Mali, the Global Fund to Fight AIDS, Tuberculosis and Malaria, and the US President's Malaria Initiative. METHODS Data from nationally representative household surveys conducted from 2000 to 2015 was used to performed the trend analysis for malaria intervention coverage, prevalence of morbidities among children under 5 years old [parasitemia and severe anaemia (< 8 g/dl)], and all-cause mortality of children under 5 (ACCM). Prevalence of contextual factors likely to contribute to ACCM were also assessed. The impact of these interventions was assessed on malaria morbidity and mortality using a plausibility argument. With the assumption that malaria contributes significantly to under-five mortality in settings with high malaria transmission, associations between malaria control interventions and all-cause under-five mortality (ACCM) were assessed taking into account other contextual factors related to child survival. RESULTS Intervention coverage improved significantly from 2006 to 2012. Household ownership of ITN increased from 49% in 2006 to 84% in 2012. ITN use also increased over the same period, from 26% in 2006 to 69% in 2012 among children under 5 and from 28% in 2006 to 73% in 2012 among pregnant women. The coverage of intermittent preventive treatment in pregnancy (IPTp) using two or more doses of SP increased from 10% in 2006 to 29% in 2012. In 2010, 23% of febrile children under 5 received ACT, as opposed to 19% in 2012. The prevalence of Plasmodium falciparum infection increased from 2010 (38.6%) to 2012 (51.6%), followed by a decrease in 2015 (35.8%). The prevalence of severe anaemia decreased from 2010 (26.3%) to 2012 (20.6%) and continued to decline in 2015 (19.9%). An impressive decline in ACCM was observed, from 225 in 1997-2001 to 192 in 2002-2006 and 95 in 2008-2012. Changes in contextual factors such as climate, socio-economic, nutrition, and coverage of maternal and child health interventions over the evaluation period did not favour reductions in ACCM, and are therefore unlikely to explain the observed results. CONCLUSIONS Taken as a whole, the evidence supports the conclusion that malaria control interventions substantially contributed to the observed decline in ACCM in Mali from 2000 to 2012, even in the context of continued high prevalence of parasitaemia explained by contextual factors such as climate change and political instability.
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Affiliation(s)
- Kassoum Kayentao
- Malaria Research and Training Center (MRTC), University of Sciences, Techniques and Technologies of Bamako (USTTB), Bamako, Mali.
| | - Lia S Florey
- President's Malaria Initiative (PMI), U.S. Agency for International Development (USAID), Washington, District of Columbia, USA
| | - Jules Mihigo
- US President's Malaria Initiative, United States Agency for International Development (USAID), Bamako, Mali
| | | | - Aliou Diallo
- US President's Malaria Initiative, United States Agency for International Development (USAID), Bamako, Mali
| | - Diakalia Koné
- National Malaria Control Programme (NMCP), Bamako, Mali
| | - Ogobara Doumbo
- Malaria Research and Training Center (MRTC), University of Sciences, Techniques and Technologies of Bamako (USTTB), Bamako, Mali
| | - Erin Eckert
- President's Malaria Initiative (PMI), U.S. Agency for International Development (USAID), Washington, District of Columbia, USA
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Hershey CL, Bhattarai A, Florey LS, McElroy PD, Nielsen CF, Yé Y, Eckert E, Franca-Koh AC, Shargie E, Komatsu R, Smithson P, Thwing J, Mihigo J, Herrera S, Taylor C, Shah J, Mouzin E, Yoon SS, Salgado SR. Implementing Impact Evaluations of Malaria Control Interventions: Process, Lessons Learned, and Recommendations. Am J Trop Med Hyg 2017; 97:20-31. [PMID: 28990921 PMCID: PMC5619934 DOI: 10.4269/ajtmh.17-0064] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/25/2017] [Accepted: 05/30/2017] [Indexed: 11/07/2022] Open
Abstract
As funding for malaria control increased considerably over the past 10 years resulting in the expanded coverage of malaria control interventions, so did the need to measure the impact of these investments on malaria morbidity and mortality. Members of the Roll Back Malaria (RBM) Partnership undertook impact evaluations of malaria control programs at a time when there was little guidance in terms of the process for conducting an impact evaluation of a national-level malaria control program. The President's Malaria Initiative (PMI), as a member of the RBM Partnership, has provided financial and technical support for impact evaluations in 13 countries to date. On the basis of these experiences, PMI and its partners have developed a streamlined process for conducting the evaluations with a set of lessons learned and recommendations. Chief among these are: to ensure country ownership and involvement in the evaluations; to engage stakeholders throughout the process; to coordinate evaluations among interested partners to avoid duplication of efforts; to tailor the evaluation to the particular country context; to develop a standard methodology for the evaluations and a streamlined process for completion within a reasonable time; and to develop tailored dissemination products on the evaluation for a broad range of stakeholders. These key lessons learned and resulting recommendations will guide future impact evaluations of malaria control programs and other health programs.
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Affiliation(s)
- Christine L. Hershey
- President’s Malaria Initiative, U.S. Agency for International Development, Washington, District of Columbia
| | - Achuyt Bhattarai
- Malaria Branch and President’s Malaria Initiative, Centers for Disease Control and Prevention, Atlanta, Georgia
| | - Lia S. Florey
- The DHS Program, ICF International, Rockville, Maryland
| | - Peter D. McElroy
- Malaria Branch and President’s Malaria Initiative, Centers for Disease Control and Prevention, Atlanta, Georgia
| | - Carrie F. Nielsen
- Malaria Branch and President’s Malaria Initiative, Centers for Disease Control and Prevention, Atlanta, Georgia
| | - Yazoume Yé
- MEASURE Evaluation, ICF International, Rockville, Maryland
| | - Erin Eckert
- President’s Malaria Initiative, U.S. Agency for International Development, Washington, District of Columbia
| | | | - Estifanos Shargie
- The Global Fund to Fight AIDS, Tuberculosis and Malaria, Geneva, Switzerland
| | - Ryuichi Komatsu
- The Global Fund to Fight AIDS, Tuberculosis and Malaria, Geneva, Switzerland
| | | | - Julie Thwing
- Malaria Branch and President’s Malaria Initiative, Centers for Disease Control and Prevention, Atlanta, Georgia
| | - Jules Mihigo
- President’s Malaria Initiative, Centers for Disease Control and Prevention, Bamako, Mali
| | | | | | - Jui Shah
- MEASURE Evaluation, ICF International, Rockville, Maryland
| | - Eric Mouzin
- Roll Back Malaria Partnership, Geneva, Switzerland
| | - Steven S. Yoon
- Malaria Branch and President’s Malaria Initiative, Centers for Disease Control and Prevention, Atlanta, Georgia
| | - S. René Salgado
- President’s Malaria Initiative, U.S. Agency for International Development, Washington, District of Columbia
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