<i>Plasmodium falciparum</i><i>pfhrp2</i> and <i>pfhrp3</i> Gene Deletions and Relatedness to Other Global Isolates, Djibouti, 2019–2020
Eric Rogier, Jessica N. McCaffery, Mohamed Ali Mohamed, Camelia Herman, Doug Nace, Rachel F. Daniels, Naomi W. Lucchi, Sophie Jones, Ira F. Goldman, Michael Aidoo, Qin Cheng, Edie A. Kemenang, Venkatachalam Udhayakumar, Jane Cunningham
Abstract
Plasmodium falciparum infection has greatly improved in many malaria-endemic settings through the use of rapid diagnostic tests (RDTs) that detect the histidine-rich protein 2 (HRP2) antigen (1). As the only Plasmodium species infecting humans to produce this antigen, the P. falciparum parasite expresses HRP2 in abundance and releases it into the bloodstream during blood-stage infection, making this marker a very sensitive and specific target for falciparum malaria (1,2). The pfhrp2 gene is located on chromosome 8 of the parasite genome, and a paralogous gene (pfhrp3) is located on chromosome 13. The 2 protein products share common epitopes for diagnostic antibodies, enabling the HRP3 antigen to also be detected to some extent by HRP2based RDTs (3-6).