Progress in the Study of Epidemiologic Characteristics and Influencing Factors of Asymptomatic Malaria Infection in Africa

Abstract

Malaria is caused by protozoan parasitic Plasmodium infections. Plasmodium falciparum is common in Africa; P ovale, P malaria and P vivax infections are less prevalent and globally confined, contributing to major causes of global mortality and morbidity, particularly in children in sub-Saharan African countries. In 2018, the total incidence of malaria increased from 221 million to 229 million, with an estimated 503 000 deaths reported. Sub-Saharan Africa has the highest number of cases of malaria and highest mortality rate compared with other countries, like southeastern Asia, east Pacific, western, and America with an estimated 213 million cases. In addition, continuous exposure to Plasmodium parasites results in the production of partial immunity to guard against more problems, resulting in asymptomatic carriers. The diagnosis of asymptomatic malaria is not simple because of the apparent absence of clinical factors and sometimes low levels of parasites. The most basic concept appears to be parasitemia and a lack of malaria signs, primarily fever (axillary temperature <37.5° C). Thus, a better awareness of asymptomatic malaria epidemiology in affected countries will help improve strategies to reduce the local burden of malaria and its health consequences. Therefore, the objective of this study was to determine the magnitude of asymptomatic malaria pathology and related risk factors with epidemiologic characteristics in individuals on the African continent.