Low prevalence of Plasmodium falciparum histidine-rich protein 2 and 3 gene deletions in malaria-endemic states of India.

Rapid diagnostic tests (RDTs) are crucial for diagnosing malaria in resource-limited settings. These tests, which detect the histidine-rich protein 2 (PfHRP2) and its structural homologue PfHRP3, are specifically designed to identify Plasmodium falciparum. Deletion of the Pfhrp2 gene in parasite has been reported in India and other malaria-endemic countries. Therefore, periodic surveillance of Pfhrp2 and Pfhrp3 genetic deletions is crucial. We conducted a study to examine these gene deletions in P. falciparum isolates from nine malaria-endemic states in India. In this study, we analyzed 1,558 samples that were microscopically confirmed to be P. falciparum positive. We isolated genomic DNA from all the aforementioned samples, followed by PCR amplification of the Pfhrp2/3 gene. The results showed that the deletion rates for Pfhrp2 and Pfhrp3 genes were 0.44% and 1.47%, respectively. These findings indicate that the gene deletions in all nine states are at low level. Despite these low deletion rates, continuous surveillance is crucial to monitor the efficiency of HRP2 based malaria RDTs. It is recommend that conducting large-scale studies which include other endemic states in India to gain a more comprehensive understanding of the prevalence and impact of these gene deletions over time. This ongoing surveillance will ensure that diagnostic strategies remain effective and that any emerging trends in gene deletions are promptly addressed to achieve the malaria control and elimination.