{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2026,3,18]],"date-time":"2026-03-18T21:33:20Z","timestamp":1773869600504,"version":"3.50.1"},"reference-count":40,"publisher":"American Society of Tropical Medicine and Hygiene","issue":"2","content-domain":{"domain":[],"crossmark-restriction":false},"short-container-title":[],"published-print":{"date-parts":[[2025,2,5]]},"abstract":"<jats:title>ABSTRACT.<\/jats:title>\n<jats:p>Placental malaria is an important cause of fetomaternal morbidity and mortality among pregnant women infected with <jats:italic>Plasmodium falciparum<\/jats:italic>. The pathogenesis involves the binding of VAR2CSA on the surface of infected erythrocytes to chondroitin sulfate proteoglycans on syncytiotrophoblasts in the intervillous space of the placenta. Anti-VAR2CSA antibodies confer protection from adverse pregnancy outcomes in falciparum malaria; therefore, VAR2CSA is a strong vaccine candidate against placental malaria. To date, little is known about transcription of <jats:italic>var2csa<\/jats:italic> among isolates from male and nonpregnant patients in low transmission areas. In this study, transcription and copy number variation of <jats:italic>var2csa<\/jats:italic> were analyzed in 55\u2009<jats:italic>P. falciparum<\/jats:italic> isolates from nonpregnant women, men and children with symptomatic malaria in five endemic provinces of Thailand. Reverse transcription polymerase chain reaction (PCR) detected <jats:italic>var2csa<\/jats:italic> transcripts in 43 (78.2%) blood samples. Multiple copies of <jats:italic>var2csa<\/jats:italic> were identified in 16 of 55 (29.1%) isolates by quantitative real-time PCR. Copy number variation of <jats:italic>var2csa<\/jats:italic> was not associated with the patients\u2019 sex, age group, ethnicity, parasite genotypes, parasite density, and geographic origins. These data suggest that <jats:italic>P. falciparum<\/jats:italic> carrying multicopy <jats:italic>var2csa<\/jats:italic> had a wide geographic distribution in Thailand with a prevalence rate comparable to those observed in high transmission areas of Africa. The high prevalence of isolates from male and nonpregnant patients with <jats:italic>var2csa<\/jats:italic> transcription suggests that the transcription of this gene occurs naturally during blood stage infection. Whether VAR2CSA is expressed and immunogenic among nonpregnant falciparum malaria patients requires further study.<\/jats:p>","DOI":"10.4269\/ajtmh.24-0065","type":"journal-article","created":{"date-parts":[[2024,11,19]],"date-time":"2024-11-19T15:49:11Z","timestamp":1732031351000},"page":"266-273","source":"Crossref","is-referenced-by-count":3,"title":["Transcription and Copy Number Variation of Plasmodium falciparum var2csa among Nonpregnant Malaria Patients in Thailand"],"prefix":"10.4269","volume":"112","author":[{"given":"Sethawud","family":"Chaikitgosiyakul","sequence":"first","affiliation":[{"name":"Molecular Biology of Malaria and Opportunistic Parasites Research Unit, Department of Parasitology, Faculty of Medicine, Chulalongkorn University, Bangkok, Thailand;"},{"name":"Inter-Department Program of Biomedical Sciences, Faculty of Graduate School, Chulalongkorn University, Bangkok, Thailand;"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Napaporn","family":"Kuamsab","sequence":"additional","affiliation":[{"name":"Molecular Biology of Malaria and Opportunistic Parasites Research Unit, Department of Parasitology, Faculty of Medicine, Chulalongkorn University, Bangkok, Thailand;"},{"name":"Community Public Health Program, Faculty of Health Science and Technology, Southern College of Technology, Nakorn Si Thammarat, Thailand"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Taweesak","family":"Tia","sequence":"additional","affiliation":[{"name":"Molecular Biology of Malaria and Opportunistic Parasites Research Unit, Department of Parasitology, Faculty of Medicine, Chulalongkorn University, Bangkok, Thailand;"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Chaturong","family":"Putaporntip","sequence":"additional","affiliation":[{"name":"Molecular Biology of Malaria and Opportunistic Parasites Research Unit, Department of Parasitology, Faculty of Medicine, Chulalongkorn University, Bangkok, Thailand;"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Somchai","family":"Jongwutiwes","sequence":"additional","affiliation":[{"name":"Molecular Biology of Malaria and Opportunistic Parasites Research Unit, Department of Parasitology, Faculty of Medicine, Chulalongkorn University, Bangkok, Thailand;"}],"role":[{"role":"author","vocabulary":"crossref"}]}],"member":"2795","reference":[{"key":"b1","series-title":"Adv Parasitol","doi-asserted-by":"crossref","first-page":"53","DOI":"10.1016\/bs.apar.2024.02.001","article-title":"PfEMP1 and var genes\u2014Still of key importance in Plasmodium falciparum malaria pathogenesis and immunity","volume":"125","author":"Hviid","year":"2024"},{"key":"b2","series-title":"Mol Microbiol","first-page":"179","article-title":"Selective upregulation of a single distinctly structured var gene in chondroitin sulphate A-adhering Plasmodium falciparum involved in 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