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Sierra Leone relies heavily on histidine-rich protein 2–based diagnostics for malaria because of the high transmission of Plasmodium falciparum. During the 2015 recombinant vesicular stomatitis virus (VSV)−Zaire Ebola virus envelope glycoprotein (GP) vaccine trial, 77 participants with asymptomatic Plasmodium infection were enrolled, with all but four having P. falciparum malaria. Of the 73 participants with P. falciparum malaria, one infection (1 of 73, 1.4%; 95% CI, 0.03–7.4) showed P. falciparum with a pfhrp3 single deletion, and two P. falciparum infections (2 of 73, 2.7%; 95% CI, 0.03–9.6) showed pfhrp2/pfhrp3 dual deletions. This study shows evidence of pfhrp2- and pfhrp3-deleted parasites in Freetown, Sierra Leone. Additional studies for more precise estimates of prevalence are warranted.
Financial support: The STRIVE study was supported by the Centers for Disease Control and Prevention (CDC), the Biomedical Advanced Research and Development Authority, and the NIH, with additional support from the CDC Foundation. The STRIVE immunogenicity sub-study was supported by the U.S. Department of Health and Human Services, the Office of the Assistant Secretary of Preparedness and Response, and the Biomedical Advanced Research and Development Authority (contracts HHSO10201500002C, HHSO10201600031C, and HHSO10201700012C) and by the U.S. Department of Defense, Defense Threat Reduction Agency (contract HDTRA1-15-C-0058). This research was also supported in part by appointments through the Research Participation Program at the CDC administered by the Oak Ridge Institute for Science and Education through an interagency agreement between the U.S. Department of Energy and the CDC.
Disclaimer: The findings and conclusions in this report are those of the authors and do not necessarily represent the official position of the CDC.
Authors’ addresses: Jessica N. McCaffery, Malaria Branch, Division of Parasitic Diseases and Malaria, Centers for Disease Control and Prevention, Atlanta, GA, and Oak Ridge Associated Universities, Oak Ridge, TN, E-mail: firstname.lastname@example.org. Curtis S. Huber and Eric Rogier, Malaria Branch, Division of Parasitic Diseases and Malaria, Centers for Disease Control and Prevention, Atlanta, GA, E-mails: email@example.com and firstname.lastname@example.org. Hindolo M. Samai, College of Medicine and Allied Health Sciences, University of Sierra Leone, Freetown, Sierra Leone, E-mail: email@example.com.