The prevalence and density of asymptomatic plasmodium infections among children in a rural community of South- Western Nigeria.

Abstract

Asymptomatic malaria is highly prevalent in endem ic areas of Africa and it is a new challenge for the malaria elimination agenda. In recent years, the number of hospitalizations due to malaria cases in sub-Saharan Africa has steadily  decreased. However, there are indications that this positive trend could suffer a setback due to asymptomatic malaria cases, which may serve as reservoir of infections for vulnerable populations. This cross-sectional study examined the prevalence of asymptomatic malaria in school-aged children living in a rural community in  South- West, Nigeria. The study was conducted from August to September 2020, involving 300 randomly selected school children. Histidine rich protein II rapid diagnostic test kits (HRP2) were used to screen participants for malaria. All blood samples were further examined microscopically using 3% Giemsa-stained blood smears for confirmation, speciation, and parasites. The anaemia status of the children was quantification  of malaria determined by measuring the haematocrit. Statistical analysis of the data was done using the chi-square test, student t-test, Mann Whitney U test and Kruskal-Wallis rank sum tests to determine the association between variables and the difference in mean/median with a significance level p≤ 0.05. The results showed a high prevalence of asymptomatic malaria of 41% by microscopy. The prevalence of asymptomatic malaria was statistically significantly higher among children aged 6 to 11 years (52%), compared to children >12years (37%), and < 5years old (13%), (p=0.00001). Plasmodium falciparum was responsible for  96% of the infection while the remaining 4% had multiple infections with Plasmodium falciparum and Plasmodium ovale. This study confirms that the prevalence of asymptomatic cases of malaria among children in malaria endemic areas is high and they will benefit from malaria chemoprophylaxis.