Circulation of Non-falciparum species in Niger: Implications for malaria diagnosis

Rationale Niger’s National Malaria Control Programme (NMCP) and its partners use HRP2-based RDTs which are specific to Plasmodium falciparum diagnosis. This study aimed to screen for the circulation of Non-falciparum species in Zinder, a region of Niger, West Africa. Methods A cross-sectional study was carried out from July to December 2022 at the district hospital of the Zinder region of Niger. PfHRP2-RDTs were performed, and Dried blood spots (DBS) samples were collected for further laboratory multiplexed PET-PCR analysis on positive light microscopy from all febrile patients who attended the Zinder district hospital during the study period. Results Three hundred forty (340) DBS were collected and analyzed by the PET-PCR. Overall, 73.2% [95% CI 68.2-77.9%] (249/340) were positive for Plasmodium genus and species and represented the study population. The Plasmodium species proportions are 89.5% [95% CI 85.1-93.1%] (223/249) for Plasmodium falciparum, 38.5% [95% CI 32.5-44.9%] (96/249) for Plasmodium malariae, 10.8% [95% CI 7.3-15.4%] (27/249) for Plasmodium vivax, and 1.6% [95% CI 0.4-4.1%] (4/249) for P. ovale. Single infection with Plasmodium species counted for 61.8% [95% CI 55.5-67.9%] (154/249), and the mixed infections rate, with at least two Plasmodium species, was 38.1% [95% CI 32.1-44.5%] (95/249). The overall single Non-falciparum infections represented a rate of 10.0% [95% CI 6.6-14.5%] (25/249). Conclusions This study confirms the first evidence of Plasmodium vivax by PET-PCR in Niger in addition to the other three Plasmodium species. These findings underline the need to adapt malaria diagnostic tools and therapeutic management as well as the training of microscopists for recognition of Non-falciparum plasmodial species circulating in the country which will better inform the strategies towards malaria control and elimination as well as the decision-making of the health authorities of Niger.