Cross-sectional prevalence and pattern of non-anaemia severe malaria among 2-10 year olds in Sokoto in Northwestern Nigeria

Malaria is highly prevalent in Nigeria and accounts for approximately 40% of global malaria mortality. However, most reports on severe malaria in Nigeria are from hospital-based studies without accurate information from communities; thus, malaria-related deaths in the community are left untracked. This study aimed to describe the prevalence and pattern of severe malaria in a community in Northwestern Nigeria. A cross-sectional study was conducted among 2-10-year-old children in Sokoto, in August and December 2016, to determine the endemicity of malaria based on Plasmodium falciparum prevalence rate (PfPR2-10) and to describe the disease pattern. Severe malaria was diagnosed according to the World Health Organisation criteria. Data were described using Stata version 15. The prevalence of non-anaemia severe malaria was higher than expected (2.6%), considering the endemicity pattern which was mesoendemic based on a PfPR2-10 of 34.8%. The mean age of children with severe malaria was 3.73 years, and the male-female ratio was 2:1. However, 54.0% of the patients had hyperparasitaemia. A relatively high prevalence of non-anaemia severe malaria was found in Wamakko. This finding suggests the need to identify and treat cases in the community using modifications of current strategies, particularly seasonal malaria chemoprophylaxis.

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

Background: Malaria is caused by one of five currently known Plasmodium 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 Plasmodium falciparum. Generally, about 98% of cases of uncomplicated malaria in most regions surveyed in Nigeria recently is due to P. falciparum, with the remainder being due to P. malariae. This study aimed to determine the proportions of Plasmodium parasites causing uncomplicated malaria in Wamakko Local Government Area of Sokoto State, north-western Nigeria.

Methods: 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.

 Results: 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 Plasmodium falciparum 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.

Conclusions: Despite the intermediate endemicity in the area. P. falciparum monoparasitaemia affirms theories of disappearance of other parasite species, either due to faltering control of P. falciparum or more efficient control of other species.