{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2026,10,15]],"date-time":"2026-10-15T05:38:47Z","timestamp":1792042727283,"version":"4.4.0"},"reference-count":25,"publisher":"Public Library of Science (PLoS)","issue":"1","license":[{"start":{"date-parts":[[2025,1,15]],"date-time":"2025-01-15T00:00:00Z","timestamp":1736899200000},"content-version":"vor","delay-in-days":0,"URL":"http:\/\/creativecommons.org\/licenses\/by\/4.0\/"}],"funder":[{"name":"A*MIdex","award":["International 2018"],"award-info":[{"award-number":["International 2018"]}]}],"content-domain":{"domain":["www.plosglobalpublichealth.org"],"crossmark-restriction":false},"short-container-title":["PLOS Glob Public Health"],"abstract":"<jats:p>\n                    Seasonal malaria chemoprevention (SMC) with sulfadoxine-pyrimethamine and amodiaquine is recommended by the World Health Organization since 2012 for clinical malaria prevention in children in the Sahelian region of Africa. In Senegal, SMC implementation began in 2013 and is given to children under 10 years old. This study aimed to describe clinical malaria incidence in the general population during routine SMC implementation and to analyse how SMC timing impacted clinical malaria dynamics in eligible children. We conducted an ecological study in the Kedougou region of Senegal in 27 villages included in the Bandafassi Health and Demographic Surveillance System (HDSS). We calculated weekly\n                    <jats:italic>Plasmodium falciparum<\/jats:italic>\n                    malaria incidence by age group using malaria case data recorded by community health workers and health-posts, and population denominators obtained from Bandafassi Health and Demographic Surveillance System. We used negative binomial generalized additive multilevel models to analyse the incidence of clinical episodes in children under 10 years during the expected SMC prophylactic period and at the end of the transmission period. Malaria incidence was strongly seasonal with a high transmission period starting in June. Children under SMC presented an overall lower incidence compared to older children and young adults. Among children eligible for SMC, the incidence was lowest for approximately 3 weeks after treatment administration and increased subsequently, suggesting a gradual loss of protection. At the end of the high transmission period, a higher malaria incidence was recorded from the 3\n                    <jats:sup>rd<\/jats:sup>\n                    to 6\n                    <jats:sup>th<\/jats:sup>\n                    week after the week of administration of the fourth (final) SMC round. While protecting children under 10 years, SMC warrants adjustment to reduce exposure before the next round, to increase protection of 5\u20139 years, and to cover the high transmission period completely. The addition of a 5\n                    <jats:sup>th<\/jats:sup>\n                    round of SMC in 2023 was necessary to cover the end of the transmission season, but individual-level studies are required to ensure that drug efficacy and adequate dosing are maintained.\n                  <\/jats:p>","DOI":"10.1371\/journal.pgph.0003197","type":"journal-article","created":{"date-parts":[[2025,1,15]],"date-time":"2025-01-15T13:42:23Z","timestamp":1736948543000},"page":"e0003197","update-policy":"https:\/\/doi.org\/10.1371\/journal.pgph.corrections_policy","source":"Crossref","is-referenced-by-count":7,"title":["Impact of seasonal malaria chemoprevention timing on clinical malaria incidence dynamics in the Kedougou region, Senegal"],"prefix":"10.1371","volume":"5","author":[{"ORCID":"https:\/\/orcid.org\/0009-0008-7051-1582","authenticated-orcid":true,"given":"Betty","family":"Kazanga","sequence":"first","affiliation":[],"role":[{"vocabulary":"crossref","role":"author"}]},{"ORCID":"https:\/\/orcid.org\/0000-0001-8935-6529","authenticated-orcid":true,"given":"El-Hadj","family":"Ba","sequence":"additional","affiliation":[],"role":[{"vocabulary":"crossref","role":"author"}]},{"ORCID":"https:\/\/orcid.org\/0000-0002-1962-4687","authenticated-orcid":true,"given":"Eva","family":"Legendre","sequence":"additional","affiliation":[],"role":[{"vocabulary":"crossref","role":"author"}]},{"ORCID":"https:\/\/orcid.org\/0000-0002-0200-8191","authenticated-orcid":true,"given":"Mady","family":"Cissoko","sequence":"additional","affiliation":[],"role":[{"vocabulary":"crossref","role":"author"}]},{"ORCID":"https:\/\/orcid.org\/0000-0001-8261-4644","authenticated-orcid":true,"given":"Laurence","family":"Fleury","sequence":"additional","affiliation":[],"role":[{"vocabulary":"crossref","role":"author"}]},{"ORCID":"https:\/\/orcid.org\/0009-0008-1960-6463","authenticated-orcid":true,"given":"Lucas","family":"B\u00e9rard","sequence":"additional","affiliation":[],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Abdoulaye","family":"Diop","sequence":"additional","affiliation":[],"role":[{"vocabulary":"crossref","role":"author"}]},{"ORCID":"https:\/\/orcid.org\/0000-0003-4810-8232","authenticated-orcid":true,"given":"Cheikh","family":"Sokhna","sequence":"additional","affiliation":[],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Fode","family":"Danfakha","sequence":"additional","affiliation":[],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Issaka","family":"Sagara","sequence":"additional","affiliation":[],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Jean-Louis","family":"Ndiaye","sequence":"additional","affiliation":[],"role":[{"vocabulary":"crossref","role":"author"}]},{"ORCID":"https:\/\/orcid.org\/0000-0001-9006-5729","authenticated-orcid":true,"given":"Jean","family":"Gaudart","sequence":"additional","affiliation":[],"role":[{"vocabulary":"crossref","role":"author"}]},{"ORCID":"https:\/\/orcid.org\/0000-0001-8619-9775","authenticated-orcid":true,"given":"Jordi","family":"Landier","sequence":"additional","affiliation":[],"role":[{"vocabulary":"crossref","role":"author"}]}],"member":"340","published-online":{"date-parts":[[2025,1,15]]},"reference":[{"key":"pgph.0003197.ref001","volume-title":"WHO policy recommendation: seasonal malaria chemoprevention (SMC) for plasmodium falciparum malaria control in highly seasonal transmission areas of the Sahel sub-region in Africa","author":"World Health Organization","year":"2012"},{"issue":"9","key":"pgph.0003197.ref002","doi-asserted-by":"crossref","first-page":"e1003727","DOI":"10.1371\/journal.pmed.1003727","article-title":"Effectiveness of seasonal malaria chemoprevention (SMC) treatments when SMC is implemented at scale: case-control studies in 5 countries","volume":"18","author":"M Cairns","year":"2021","journal-title":"PLoS Med"},{"key":"pgph.0003197.ref003","doi-asserted-by":"crossref","first-page":"216","DOI":"10.12688\/wellcomeopenres.18057.3","article-title":"Effectiveness of seasonal malaria chemoprevention administered in a mass campaign in the Kedougou region of Senegal in 2016: a case-control study","volume":"7","author":"IA Manga","year":"2023","journal-title":"Wellcome Open Res"},{"issue":"11","key":"pgph.0003197.ref004","doi-asserted-by":"crossref","first-page":"e1002175","DOI":"10.1371\/journal.pmed.1002175","article-title":"Effectiveness of seasonal malaria chemoprevention in children under ten years of age in Senegal: a stepped-wedge cluster-randomised trial","volume":"13","author":"B Ciss\u00e9","year":"2016","journal-title":"PLoS Med"},{"issue":"10265","key":"pgph.0003197.ref005","doi-asserted-by":"crossref","first-page":"1829","DOI":"10.1016\/S0140-6736(20)32227-3","article-title":"Effectiveness of seasonal malaria chemoprevention at scale in west and central Africa: an observational study","volume":"396","author":"E Baba","year":"2020","journal-title":"Lancet"},{"key":"pgph.0003197.ref006","volume-title":"Annual epidemiological bulletin 2021 of malaria in Senegal [Bulletin \u00e9pid\u00e9miologique annuel 2021 du paludisme au S\u00e9n\u00e9gal]","author":"National Malaria Control Program","year":"2022"},{"key":"pgph.0003197.ref007","unstructured":"U.S. President\u2019s Malaria Initiative. Senegal Malaria Operational Plan FY 2020. 2020. Available from: https:\/\/www.pmi.gov\/where-we-work\/senegal\/."},{"key":"pgph.0003197.ref008","unstructured":"National Malaria Control Program. Annual epidemiological bulletin 2019 of malaria in Senegal [Bulletin \u00e9pid\u00e9miologique annuel 2019 du paludisme au S\u00e9n\u00e9gal]. 2020. Available from: http:\/\/www.pnlp.sn\/."},{"key":"pgph.0003197.ref009","unstructured":"U.S. President\u2019s Malaria Initiative. Senegal Malaria Operational Plan FY 2023. 2023. Available from: https:\/\/www.pmi.gov\/where-we-work\/senegal\/."},{"key":"pgph.0003197.ref010","unstructured":"U.S. President\u2019s Malaria Initiative. Senegal Malaria Operational Plan FY 2022. 2023. Available from: https:\/\/www.pmi.gov\/where-we-work\/senegal\/."},{"issue":"8","key":"pgph.0003197.ref011","doi-asserted-by":"crossref","first-page":"4387","DOI":"10.1128\/AAC.04923-14","article-title":"Randomized noninferiority trial of dihydroartemisinin-piperaquine compared with sulfadoxine-pyrimethamine plus amodiaquine for seasonal malaria chemoprevention in burkina faso","volume":"59","author":"I Zongo","year":"2015","journal-title":"Antimicrob Agents Chemother"},{"issue":"1","key":"pgph.0003197.ref012","doi-asserted-by":"crossref","first-page":"278","DOI":"10.1186\/s13071-022-05379-4","article-title":"Sub-national tailoring of seasonal malaria chemoprevention in Mali based on malaria surveillance and rainfall data","volume":"15","author":"M Cissoko","year":"2022","journal-title":"Parasit Vectors"},{"key":"pgph.0003197.ref013","volume-title":"Summary of the implementation of the SMC in the K\u00e9dougou health district [Synth\u00e8se de la mise en \u0153uvre de la CPS dans le district sanitaire de K\u00e9dougou]","author":"PNLP","year":"2021"},{"issue":"11","key":"pgph.0003197.ref014","doi-asserted-by":"crossref","first-page":"761","DOI":"10.1093\/trstmh\/trad042","article-title":"A proposed method of grading malaria chemoprevention efficacy","volume":"117","author":"NJ White","year":"2023","journal-title":"Trans R Soc Trop Med Hyg"},{"issue":"3","key":"pgph.0003197.ref015","doi-asserted-by":"crossref","first-page":"739","DOI":"10.1093\/ije\/dyu086","article-title":"Health & demographic surveillance system profile: Bandafassi health and demographic surveillance system (Bandafassi HDSS), Senegal","volume":"43","author":"G Pison","year":"2014","journal-title":"Int J Epidemiol"},{"issue":"3","key":"pgph.0003197.ref016","doi-asserted-by":"crossref","first-page":"418","DOI":"10.3390\/atmos13030418","article-title":"Assessment of climate-driven variations in malaria transmission in Senegal using the VECTRI model","volume":"13","author":"P Fall","year":"2022","journal-title":"Atmosphere"},{"issue":"3","key":"pgph.0003197.ref017","doi-asserted-by":"crossref","first-page":"e1002762","DOI":"10.1371\/journal.pmed.1002762","article-title":"Seasonal malaria chemoprevention combined with community case management of malaria in children under 10 years of age, over 5 months, in south-east Senegal: a cluster-randomised trial","volume":"16","author":"JLA Ndiaye","year":"2019","journal-title":"PLoS Med"},{"issue":"3","key":"pgph.0003197.ref018","doi-asserted-by":"crossref","first-page":"411","DOI":"10.4269\/ajtmh.2007.77.411","article-title":"Impact of intermittent preventive anti-malarial treatment on the growth and nutritional status of preschool children in rural Senegal (west Africa)","volume":"77","author":"B Ntab","year":"2007","journal-title":"Am J Trop Med Hyg"},{"issue":"1","key":"pgph.0003197.ref019","doi-asserted-by":"crossref","first-page":"205","DOI":"10.1186\/s12936-024-05024-8","article-title":"Two decades of molecular surveillance in Senegal reveal rapid changes in known drug resistance mutations over time","volume":"23","author":"YD Ndiaye","year":"2024","journal-title":"Malar J"},{"issue":"8","key":"pgph.0003197.ref020","doi-asserted-by":"crossref","first-page":"673","DOI":"10.1016\/j.pt.2022.05.003","article-title":"Pharmacokinetic considerations in seasonal malaria chemoprevention","volume":"38","author":"P Chotsiri","year":"2022","journal-title":"Trends Parasitol"},{"key":"pgph.0003197.ref021","doi-asserted-by":"crossref","first-page":"363","DOI":"10.1186\/s12936-016-1399-y","article-title":"The role of early detection and treatment in malaria elimination","volume":"15","author":"J Landier","year":"2016","journal-title":"Malar J"},{"issue":"11","key":"pgph.0003197.ref022","doi-asserted-by":"crossref","first-page":"3982","DOI":"10.3390\/ijerph17113982","article-title":"Geo-epidemiology of malaria at the health area level, Dire Health District, Mali, 2013-2017","volume":"17","author":"M Cissoko","year":"2020","journal-title":"Int J Environ Res Public Health"},{"issue":"11","key":"pgph.0003197.ref023","doi-asserted-by":"crossref","first-page":"1005","DOI":"10.1056\/NEJMoa2026330","article-title":"Seasonal malaria vaccination with or without seasonal malaria chemoprevention","volume":"385","author":"D Chandramohan","year":"2021","journal-title":"N Engl J Med"},{"key":"pgph.0003197.ref024","volume-title":"Malaria indicators survey in Senegal 2020-2021 [Enqu\u00eate des Indicateurs du Paludisme au S\u00e9n\u00e9gal 2020-2021]","author":"National Agency for Statistics and Demography","year":"2022"},{"issue":"3","key":"pgph.0003197.ref025","doi-asserted-by":"crossref","first-page":"279","DOI":"10.1603\/0022-2585-40.3.279","article-title":"Bionomics of anopheles gambiae giles, an. arabiensis patton, an. Funestus giles and an. nili (Theobald) (Diptera: Culicidae) and transmission of plasmodium falciparum in a sudano-guinean zone (Ngari, Senegal)","volume":"40","author":"I Dia","year":"2003","journal-title":"J Med Entomol"}],"container-title":["PLOS Global Public Health"],"original-title":[],"language":"en","link":[{"URL":"https:\/\/dx.plos.org\/10.1371\/journal.pgph.0003197","content-type":"unspecified","content-version":"vor","intended-application":"similarity-checking"}],"deposited":{"date-parts":[[2025,1,15]],"date-time":"2025-01-15T13:42:50Z","timestamp":1736948570000},"score":1,"resource":{"primary":{"URL":"https:\/\/dx.plos.org\/10.1371\/journal.pgph.0003197"}},"subtitle":[],"editor":[{"given":"Ruth","family":"Ashton","sequence":"first","affiliation":[],"role":[{"vocabulary":"crossref","role":"editor"}]}],"short-title":[],"issued":{"date-parts":[[2025,1,15]]},"references-count":25,"journal-issue":{"issue":"1","published-online":{"date-parts":[[2025,1,15]]}},"URL":"https:\/\/doi.org\/10.1371\/journal.pgph.0003197","relation":{"has-preprint":[{"id-type":"doi","id":"10.1101\/2024.04.16.24305915","asserted-by":"object"}]},"ISSN":["2767-3375"],"issn-type":[{"value":"2767-3375","type":"electronic"}],"subject":[],"published":{"date-parts":[[2025,1,15]]}}}