Epidemiology of Plasmodium falciparum infection and drug resistance markers in Ota Area, Southwestern Nigeria

Purpose: Effective routine monitoring and surveillance of parasite genes is a necessary strategy in the control of parasites’ resistance to antimalarial drugs, according to the WHO’s recommendation. This cross-sectional study therefore aimed at carrying out an epidemiological analysis on malaria incidence in Ado-Odo/Ota, Ogun State. Patients and methods: Blood and corresponding saliva samples were collected from 1,243 subjects of all ages and sex presenting with fever and a parasitemia level ≥2,000 between September 2016 and March 2018. Samples were collected from selected health facilities in the study area of Ogun state to establish the prevalence of falciparum malaria and determine resistance genes harbored by the parasites. The overall prevalence of falciparum malaria in the study site by microscopic examination was 45.86%. The highest incidence of 57.42% was recorded among male subjects. Point mutations of K76T and N86Y in the Pfcrt and pfmdr-1 genes, as well as non-synonymous mutations in Pfk13 genes, were screened for and sequenced for further analysis. Results: Pfcrt was detectable in 57.42% of blood and 51.02% of saliva samples, respectively. About 34.78% of the subjects that were confirmed microscopically harbored the Pfmdr-1 mutated gene while 26.67% of the saliva samples revealed Pfmdr-1. Epidemiological studies identified the presence of wild-type Pfk13 genes in 21.84% of blood and 44.44% of saliva samples correspondingly. For each of the genes evaluated, saliva portrayed great diagnostic performance when compared with blood. Conclusion: Findings from this study have established the prevalence of malaria and the resistance pattern of P. falciparum in the study area. The findings may help in formulating drug policies and suggest the use of saliva as a noninvasive point-of-care method of diagnosing malaria potentially deployable to rural endemic areas.