{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2025,10,23]],"date-time":"2025-10-23T16:44:22Z","timestamp":1761237862398},"reference-count":19,"publisher":"Springer Science and Business Media LLC","issue":"1","content-domain":{"domain":["link.springer.com"],"crossmark-restriction":false},"short-container-title":["Malar J"],"published-print":{"date-parts":[[2011,12]]},"abstract":"<jats:title>Abstract<\/jats:title>\n          <jats:sec>\n            <jats:title>Background<\/jats:title>\n            <jats:p>This study aimed to explore <jats:italic>Plasmodium falciparum<\/jats:italic> population dynamics during the early phase of anti-malarial drug treatment with artemisinin-based combination therapy in children with clinical malaria in a high transmission area in Africa.<\/jats:p>\n          <\/jats:sec>\n          <jats:sec>\n            <jats:title>Methods<\/jats:title>\n            <jats:p>A total of 50 children aged 1-10 years with acute uncomplicated <jats:italic>P. falciparum<\/jats:italic> malaria in Bagamoyo District, Tanzania, were enrolled. Participants were hospitalized and received supervised standard treatment with artemether-lumefantrine according to body weight in six doses over 3 days. Blood samples were collected 11 times, i.e. at time of diagnosis (-2 h) and 0, 2, 4, 8, 16, 24, 36, 48, 60 and 72 h after initiation of treatment. Parasite population dynamics were assessed using nested polymerase chain reaction (PCR)-genotyping of <jats:italic>merozoite surface protein (msp) 1<\/jats:italic> and <jats:italic>2<\/jats:italic>.<\/jats:p>\n          <\/jats:sec>\n          <jats:sec>\n            <jats:title>Results<\/jats:title>\n            <jats:p>PCR-analyses from nine sequential blood samples collected after initiation of treatment identified 20 and 21 additional genotypes in 15\/50 (30%) and 14\/50 (28%) children with <jats:italic>msp1<\/jats:italic> and <jats:italic>msp2<\/jats:italic>, respectively, non-detectable in the pre-treatment samples (-2 and 0 h combined). Some 15\/20 (75%) and 14\/21 (67%) of these genotypes were identified within 24 h, whereas 17\/20 (85%) and 19\/21 (90%) within 48 h for <jats:italic>msp1<\/jats:italic> and <jats:italic>msp2<\/jats:italic>, respectively. The genotype profile was diverse, and varied considerably over time both within and between patients, molecular markers and their respective families.<\/jats:p>\n          <\/jats:sec>\n          <jats:sec>\n            <jats:title>Conclusion<\/jats:title>\n            <jats:p>PCR analyses from multiple blood samples collected during the early treatment phase revealed a complex picture of parasite sub-populations. This underlines the importance of interpreting PCR-outcomes with caution and suggests that the present use of PCR-adjustment from paired blood samples in anti-malarial drug trials may overestimate assessment of drug efficacy in high transmission areas in Africa.<\/jats:p>\n            <jats:p>The study is registered at <jats:ext-link xmlns:xlink=\"http:\/\/www.w3.org\/1999\/xlink\" xlink:href=\"http:\/\/www.clinicaltrials.gov\" ext-link-type=\"uri\">http:\/\/www.clinicaltrials.gov<\/jats:ext-link> with identifier NCT00336375.<\/jats:p>\n          <\/jats:sec>","DOI":"10.1186\/1475-2875-10-380","type":"journal-article","created":{"date-parts":[[2011,12,21]],"date-time":"2011-12-21T07:19:12Z","timestamp":1324451952000},"update-policy":"http:\/\/dx.doi.org\/10.1007\/springer_crossmark_policy","source":"Crossref","is-referenced-by-count":25,"title":["Plasmodium falciparum population dynamics during the early phase of anti-malarial drug treatment in Tanzanian children with acute uncomplicated malaria"],"prefix":"10.1186","volume":"10","author":[{"given":"Anja M","family":"Carlsson","sequence":"first","affiliation":[]},{"given":"Billy E","family":"Ngasala","sequence":"additional","affiliation":[]},{"given":"Sabina","family":"Dahlstr\u00f6m","sequence":"additional","affiliation":[]},{"given":"Christopher","family":"Membi","sequence":"additional","affiliation":[]},{"given":"Isabel M","family":"Veiga","sequence":"additional","affiliation":[]},{"given":"Lars","family":"Rombo","sequence":"additional","affiliation":[]},{"given":"Salim","family":"Abdulla","sequence":"additional","affiliation":[]},{"given":"Zul","family":"Premji","sequence":"additional","affiliation":[]},{"given":"J Pedro","family":"Gil","sequence":"additional","affiliation":[]},{"given":"Anders","family":"Bj\u00f6rkman","sequence":"additional","affiliation":[]},{"given":"Andreas","family":"M\u00e5rtensson","sequence":"additional","affiliation":[]}],"member":"297","published-online":{"date-parts":[[2011,12,20]]},"reference":[{"key":"1970_CR1","volume-title":"Guidelines for the treatment of malaria","author":"World Health Organization","year":"2010","unstructured":"World Health Organization: Guidelines for the treatment of malaria. 2010, Geneva: WHO, 2","edition":"2"},{"key":"1970_CR2","volume-title":"Methods and techniques for clinical trials on antimalarial drug efficacy: genotyping to identify parasite populations","author":"MfM Venture","year":"2008","unstructured":"Venture MfM, World Health Organization: Methods and techniques for clinical trials on antimalarial drug efficacy: genotyping to identify parasite populations. 2008, Informal consultation organized by the MMV and cosponsored by the WHO 29-31 May 2007 Amsterdam"},{"key":"1970_CR3","doi-asserted-by":"publisher","first-page":"462","DOI":"10.1016\/S0169-4758(98)01340-4","volume":"14","author":"G Snounou","year":"1998","unstructured":"Snounou G, Beck HP: The use of PCR genotyping in the assessment of recrudescence or reinfection after antimalarial drug treatment. 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