Haiti is targeting malaria elimination by 2025. The Grand’Anse department in southwestern Haiti experiences one-third to half of all nationally reported Plasmodium falciparum cases. Although there are historical reports of Plasmodium vivax and Plasmodium malariae, today, non-falciparum infections would remain undetected because of extensive use of falciparum-specific histidine-rich protein 2 (HRP2) rapid diagnostic tests (RDT) at health facilities. A recent case–control study was conducted in Grand’Anse to identify risk factors for P. falciparum infection using HRP2-based RDTs (n = 1,107). Post hoc multiplex Plasmodium antigenemia and antibody (IgG) detection by multiplex bead assay revealed one blood sample positive for pan-Plasmodium aldolase, negative for P. falciparum HRP2, and positive for IgG antibodies to P. malariae. Based on this finding, we selected 52 samples with possible P. malariae infection using IgG and antigenemia data and confirmed infection status by species-specific PCR. We confirmed one P. malariae infection in a 6-month-old infant without travel history. Congenital P. malariae could not be excluded. However, our finding—in combination with historical reports of P. malariae—warrants further investigation into the presence and possible extent of non-falciparum malaria in Haiti. Furthermore, we showed the use of multiplex Plasmodium antigen and IgG detection in selecting samples of interest for subsequent PCR analysis, thereby reducing costs as opposed to testing all available samples by PCR. This is of specific use in low-transmission or eliminating settings where infections are rare.
Address correspondence to Lotus L. van den Hoogen, Center for Applied Malaria Research and Evaluation, Tulane School of Public Health and Tropical Medicine, 1440 Canal St., Suite 2350, New Orleans, LA 70112. E-mail: firstname.lastname@example.org
Disclaimer: The findings and conclusions in this report are those of the authors and do not necessarily represent the official position of the Centers for Disease Control and Prevention (CDC).
Financial support: This study was conducted by the Malaria Zero alliance (http://malariazeroalliance.org/), funded by the Bill & Melinda Gates Foundation (grant number OPP1114297) to the CDC Foundation.