Malaria Transfusional Transmission: Epidemiological Review, Screening Protocols and Prevention Mechanisms

Abstract

Malaria is a neglected tropical disease, whose main form of transmission occurs through the bite of the female Anopheles mosquito infected by the parasite Plasmodium sp. Its clinical symptoms range from asymptomatic cases to more severe and fatal conditions. Added to this natural transmission mechanism, many studies report that Malaria is one of the main infectious diseases transmitted by transfusion. There are reports of prevalence among blood donors in the five continents, with the highest number of cases in Africa, Asia and South America, regions of high endemicity. Factors such as the high prevalence rate of asymptomatic malaria carriers, as well as deficient regulation in the screening of blood donors and an ineffective hemovigilance policy make the risk of Transfusion-Transmitted Malaria (TTM) worse, exposing millions of people possible contamination by transfusion, especially in underdeveloped countries. Patients with underlying diseases or immunosuppressed who require polytransfusions are the most susceptible to TTM. After an eventual transfusion of bags contaminated by Plasmodium sp, these patients can develop the most severe form of the disease, presenting high-risk clinical complications that can culminate in fatal outcomes. In view of the facts and aiming at greater transfusion safety, it is observed that stricter regulatory policies aimed at preventing TTM are needed; such policies will be more comprehensive if coordinated by the World Health Organization (WHO) and more effective if they are adequate to the reality of endemic and non-endemic countries. In blood banks, control measures should focus mainly on broad serological coverage with high performance tests, in addition to active hemovigilance programs and encouragement of research and implementation of methods of inactivation of pathogens in blood component bags. Given the above, this study was carried out with the aim of providing knowledge of the current panorama of the prevalence of malaria among blood donors and of documented cases of TTM around the world, as well as demonstrating the disease tracking methodologies in use in different countries, and present possibilities for adopting mechanisms that allow better control of the transfusional transmission of malaria in blood banks.