{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2025,12,3]],"date-time":"2025-12-03T14:02:05Z","timestamp":1764770525413,"version":"3.46.0"},"reference-count":54,"publisher":"American Society of Tropical Medicine and Hygiene","issue":"6","content-domain":{"domain":[],"crossmark-restriction":false},"short-container-title":[],"published-print":{"date-parts":[[2025,12,3]]},"abstract":"<jats:title>ABSTRACT.<\/jats:title>\n                  <jats:p>\n                    The authors of studies in high-malaria transmission areas have associated the opsonic phagocytosis (OP) of merozoites with protection from clinical malaria; however, OP studies have not been conducted in low transmission areas. In the current study, blood samples were collected from 5,753 individuals in a Kenyan highland area of low, unstable transmission in 2007 and monitored for clinical malaria through 2017. In a nested case\u2013control design, individuals who developed clinical malaria (cases,\n                    <jats:italic>N<\/jats:italic>\n                    = 317) were matched 1:1 by age and village with those who did not (controls,\n                    <jats:italic>N<\/jats:italic>\n                    = 317). A novel OP assay was developed, and the association of OP with the risk of clinical malaria and IgG responses to\n                    <jats:italic>Plasmodium falciparum<\/jats:italic>\n                    antigens in individuals &lt;5 years old, 5\u201314 years old, and \u226515 years old was examined. Opsonic phagocytosis levels increased with age; however, the proportion of individuals who tested positive for an OP response was &lt;50% until individuals were \u226515 years old. After adjustment for potential confounding factors, OP levels were associated with an increased risk of clinical malaria in individuals 5\u201314 years old (adjusted odds ratio: 3.32 [CI: 1.13\u20139.77]) and \u226515 years old (adjusted odds ratio: 4.85 [CI: 1.02\u201323.00]), but not in children &lt;5 years old (adjusted odds ratio: 0.57 [CI: 0.20\u20131.64]). In this low-malaria transmission area, OP responses did not develop in most individuals until they were \u226515 years old, and OP levels in individuals \u22655 years old were associated with an increased risk of clinical malaria, potentially reflecting that OP levels are markers of malaria exposure, providing additional information beyond standard geographic and intervention-based risk markers.\n                  <\/jats:p>","DOI":"10.4269\/ajtmh.25-0349","type":"journal-article","created":{"date-parts":[[2025,10,9]],"date-time":"2025-10-09T19:17:29Z","timestamp":1760037449000},"page":"1267-1275","source":"Crossref","is-referenced-by-count":0,"title":["A Novel Phagocytosis Assay Reveals the Association between Elevated Opsonic Phagocytosis Levels and an Increased Risk of Clinical Malaria in a Low-Malaria Transmission Area"],"prefix":"10.4269","volume":"113","author":[{"given":"Eliud O.","family":"Odhiambo","sequence":"first","affiliation":[{"name":"Department of Microbiology and Immunology, Indiana University School of Medicine, Indianapolis, Indiana;"},{"name":"Ryan White Center for Pediatric Infectious Diseases & Global Health, Indiana University School of Medicine, Indianapolis, Indiana;"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Kagan A.","family":"Mellencamp","sequence":"additional","affiliation":[{"name":"Ryan White Center for Pediatric Infectious Diseases & Global Health, Indiana University School of Medicine, Indianapolis, Indiana;"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Prasida","family":"Holla","sequence":"additional","affiliation":[{"name":"Ryan White Center for Pediatric Infectious Diseases & Global Health, Indiana University School of Medicine, Indianapolis, Indiana;"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"George","family":"Ayodo","sequence":"additional","affiliation":[{"name":"Jaramogi Oginga Odinga University of Science and Technology, Bondo, Kenya"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Chandy C.","family":"John","sequence":"additional","affiliation":[{"name":"Department of Microbiology and Immunology, Indiana University School of Medicine, Indianapolis, Indiana;"},{"name":"Ryan White Center for Pediatric Infectious Diseases & Global Health, Indiana University School of Medicine, Indianapolis, Indiana;"}],"role":[{"role":"author","vocabulary":"crossref"}]}],"member":"2795","reference":[{"key":"b1","series-title":"Front Immunol","first-page":"594653","article-title":"Naturally acquired humoral immunity against Plasmodium falciparum malaria","volume":"11","author":"Gonzales","year":"2020"},{"key":"b2","series-title":"Crit Care","first-page":"315","article-title":"Clinical review: Severe malaria","volume":"7","author":"Trampuz","year":"2003"},{"key":"b3","series-title":"Malar J","first-page":"163","article-title":"Sensitivity of fever for diagnosis of clinical malaria in a Kenyan area of unstable, low 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Hygiene"],"original-title":[],"link":[{"URL":"https:\/\/www.ajtmh.org\/view\/journals\/tpmd\/113\/6\/article-p1267.xml","content-type":"text\/html","content-version":"vor","intended-application":"text-mining"},{"URL":"https:\/\/www.ajtmh.org\/downloadpdf\/journals\/tpmd\/113\/6\/article-p1267.xml","content-type":"text\/html","content-version":"vor","intended-application":"syndication"},{"URL":"https:\/\/www.ajtmh.org\/downloadpdf\/journals\/tpmd\/113\/6\/article-p1267.xml","content-type":"unspecified","content-version":"vor","intended-application":"similarity-checking"}],"deposited":{"date-parts":[[2025,12,3]],"date-time":"2025-12-03T13:32:10Z","timestamp":1764768730000},"score":1,"resource":{"primary":{"URL":"https:\/\/www.ajtmh.org\/view\/journals\/tpmd\/113\/6\/article-p1267.xml"}},"subtitle":[],"short-title":[],"issued":{"date-parts":[[2025,12,3]]},"references-count":54,"journal-issue":{"issue":"6"},"URL":"https:\/\/doi.org\/10.4269\/ajtmh.25-0349","relation":{},"ISSN":["0002-9637","1476-1645"],"issn-type":[{"type":"print","value":"0002-9637"},{"type":"electronic","value":"1476-1645"}],"subject":[],"published":{"date-parts":[[2025,12,3]]}}}