Molecular surveillance of pfhrp2 and pfhrp3 deletions in Plasmodium falciparum isolates from Mozambique

Abstract

Abstract Background Malaria programmes use Plasmodium falciparum histidine-rich protein-2 (PfHRP2) based rapid diagnostic tests (RDTs) for malaria diagnosis. The deletion of this target antigen could potentially lead to misdiagnosis, delayed treatment and continuation of active transmission. Methods Plasmodium falciparum isolates (n = 1162) collected in Southern Mozambique were assessed by RDTs, microscopy and/or 18SrRNA qPCR. pfhrp2 and pfhrp3 deletions were investigated in isolates from individuals who were negative by RDT but positive by microscopy and/or qPCR (n = 69) using gene-specific PCRs, with kelch13 PCR as the parasite DNA control. Results Lack of pfhrp2 PCR amplification was observed in one of the 69 isolates subjected to molecular analysis [1.45% (95% CI 0.3–7.8%)]. Conclusions The low prevalence of pfhrp2 deletions suggests that RDTs will detect the vast majority of the P. falciparum infections. Nevertheless, active surveillance for changing deletion frequencies is required.

Keywords

• Malaria
• Deletion
• RDT
• Mozambique
• Pfhrp2