Molecular Detection of Plasmodium falciparum Histidine-rich Protein 2/3 Gene (pfhrp2/3) Deletion in Timika, Papua, Indonesia

Abstract

Malaria is a major health issue worldwide, with Papua being the epicenter of malaria in Indonesia. To reduce malaria transmission, diagnostic methods have become a crucial pillar in malaria control and elimination. Due to their simplicity, rapid diagnostic tests (RDTs) are used to diagnose malaria in areas lacking expert microscopists, specifically PfHRP2-based RDTs. However, the emergence of pfhrp2/3 gene deletion in recent years has threatened the sensitivity of PfHRP2-based RDTs. The mutation can result in false-negative RDT readings, leading to misdiagnosis of P. falciparum malaria. Despite that, very limited studies regarding this mutation have been conducted in Papua, Indonesia. The study aims to determine the prevalence of pfhrp2/3 gene deletion in Timika, Papua, Indonesia. Methods: Molecular techniques, namely conventional PCR and real-time PCR, were utilized to detect pfhrp2 and pfhrp3 gene deletion in 582 samples positive for P. falciparum mono-infection by microscopy and PCR from Timika, Papua, Indonesia. Results: The study recorded the prevalence of pfhrp2 single gene, pfhrp3 single gene, and double gene deletion at 0.86%, 35.56%, and 1.89%, respectively. In addition, cases of cryptic absence were found, where the RDT results were positive but showed no amplification of the pfhrp2 gene. Conclusion: Although pfhrp2 gene deletion is present in Timika, its prevalence is insufficient to consider a change in the region’s diagnostic routine. In contrast, the prevalence of pfhrp3 gene deletion is higher than that of pfhrp2; thus, further research is required.