GEOSPATIAL DISTRIBUTION OF PFHRP2/PFHRP3 GENE DELETIONS IN KEBBI STATE: IDENTIFYING HIGH-PREVALENCE SENATORIAL DISTRICTS FOR MALARIA DIAGNOSTIC POLICY CHANGE.

Abstract

The persistence of Plasmodium falciparum histidine-rich protein 2 and 3 (pfhrp2/pfhrp3) gene deletions presents a growing challenge to malaria diagnosis using HRP2-based rapid diagnostic tests (RDTs). Evidence indicates increasing false-negative RDT results across Nigeria, potentially undermining malaria surveillance and case management. This study assessed the geospatial distribution and prevalence of pfhrp2/pfhrp3 gene deletions in Kebbi State, with. A cross-sectional molecular epidemiological survey was conducted between June 2024 and March 2025 across 12 local government areas (LGAs) representing the three senatorial districts of Kebbi State. A total of 960 blood samples were collected from confirmed malaria-positive individuals via microscopy. Samples were analyzed by PCR to detect pfhrp2 and pfhrp3 deletions. Geospatial analysis using ArcGIS 10.8 mapped the spatial distribution of deletion prevalence and identified cluster hotspots using the Getis-Ord statistic. The overall prevalence of pfhrp2 deletions was 13.5%, while pfhrp3 deletions were detected in 8.1% of isolates. Combined dual deletions were found in 4.7% of samples. Geospatial mapping revealed clustering of high-deletion prevalence in the Kebbi North senatorial district (Argungu and Arewa LGAs, pfhrp2 = 22.8%; pfhrp3 = 14.6%), moderate prevalence in Kebbi Central (Birnin Kebbi, Kalgo; pfhrp2 = 10.7%), and lowest in Kebbi South (Yauri, Zuru; pfhrp2 = 6.4%). Statistically significant hotspots (Getis= 2.31, p < 0.05) were located in the northern belt bordering Niger Republic. The spatial heterogeneity of pfhrp2/pfhrp3 deletions across Kebbi State underscores the need for region-specific diagnostic policies. HRP2-based RDTs remain largely effective in Kebbi South and Central, but alternative diagnostic methods such as pLDH-based RDTs or microscopy should be prioritized in Kebbi North.