Prevalence of Asymptomatic Malaria in Leaiten, Eritrea, 2017.

Abstract Background As much as malaria control interventions may be directed at restricting transmission through mosquito control and treatment of symptomatic cases, the effect of asymptomatic cases in the transmission of malaria has not been given too much attention. On the other hand, asymptomatic carriers do not seek treatment, becoming permanent reservoirs, and hence creating a real pose to the public health. Objective The purpose of the study was to determine the prevalence of asymptomatic malaria and its associated factors in Leaiten village, Eritrea. Methods 322 eligible participants were randomly selected and interviewed. Thin and thick blood films were collected and Giemsa-stained to determine blood parasitaemia and speciation using light microscopy. Multivariate Logistic Regression was used to assess relationship between the potential factors identified and asymptomatic malaria. Results The prevalence of asymptomatic malaria was 5.9%, with a predominantly higher proportion (P) of Plasmodium Falciparum (P= 94.7%, n=18) than Plasmodium Vivax (P= 5.3%, n=1). Most of the infections were low density and at their ring form (P = 94.7%, n = 18). Only one subject had medium density and a gametocyte stage infection (P = 5.3%). The odds of asymptomatic malaria by sex, age, occupation or education was not significantly different. Bed net usage in comparison to no usage was not a significant predictor of asymptomatic malaria (5.5% vs. 7.6, p-value = 0.519). Those with asymptomatic malaria who had previous malaria sickness (4.2%) was not significantly different to those who had never been sick (7.3%), (OR = 0.56, p-value = 0.248). People who lived near water body (8.5%) were equally likely to be asymptomatic to those who didn’t live near water body (4.9%), (OR = 1.82, p-value = 0.215), out of which, those who lived near open water body had no difference in acquiring asymptomatic malaria to those who lived near closed water body (OR = 2.26, p-value = 0.457). Conclusion This study indicated the hidden impact of asymptomatic malaria in perpetuating malaria transmission in the village. Further assessment of the impact of asymptomatic malaria, on malaria transmission, is needed based on a larger and more sensitive method.