Where have all the parasites gone? Unusual monoparasitaemia in a cross-sectional malariometric survey in northern Nigeria.

Malaria is caused by one of five currently known parasite species causing disease in humans. While modelling has provided information of the vector, the same is not entirely the case for the parasite. The World Malaria reports of 2014 to 2016 reported 100% of confirmed cases from Nigeria being due to . Generally, about 98% of cases of uncomplicated malaria in most regions surveyed in Nigeria recently is due to , with the remainder being due to . This study aimed to determine the proportions of parasites causing uncomplicated malaria in Wamakko Local Government Area of Sokoto State, north-western Nigeria. The study was a descriptive, cross-sectional study conducted during the rainy season and dry season in north-western Nigeria. The area has a 'local steppe' climate and Sudanian Savannah vegetation. Sampling was via multistage cluster sampling. Selected participants were examined for pallor, palpable splenomegaly and signs of complicated malaria. Blood samples were also taken for rapid diagnosis of malaria and thick and thin films to identify parasitaemia and the parasite species. Participants found to have malaria were treated with Artemether/Lumefantrine and those with complicated malaria were referred to the nearest hospital. We found a parasite prevalence of 34.8% overall, which was higher in the rainy season (49.3%) than in the dry season (20.2%). There was monoparasitaemia of throughout the study area, irrespective of the clinical status of the participant. Mapping of the parasite was extended throughout the Local Government Area and the State. Despite the intermediate endemicity in the area. monoparasitaemia affirms theories of disappearance of other parasite species, either due to faltering control of or more efficient control of other species.