NAT-based assay to increase blood safety and prevent transfusion-transmitted malaria in Brazil

Malaria is a vector-borne infection caused by intracellular protozoan parasites of the genus Plasmodium. The World Health Organization (WHO) Global Technical Strategy aims to reduce at least 90% of malaria cases and mortality rates by 20301. Between 2000 and 2023, more than 23 million cases and approximately 12,000 deaths have been reported in the region of the Americas. However, since 2015, the case incidence has decreased by 10%. Concerning Brazil, malaria incidence was reduced by less than 25%, like countries of Ecuador and the Bolivarian Republic of Venezuela2, in this same period. Malaria transmission in endemic and non-endemic areas is related to the Anopheles vector species. Most of cases are present in the Brazilian Amazon region. Nonetheless, the extra-Amazon region registered 1% of malaria total cases2. Several factors might impact the occurrence of malaria in countries under-development like Brazil. Poverty, deforestation and population mobility contribute to its persistence. Also, malaria is typically transmitted in tropical and subtropical areas, which means that climatic factors including temperature and rainfall impact where malaria exists. 3

Recent demographic trends highlight the growing importance of middle-aged and elderly individuals as key contributors to the blood supply. Globally and in Hong Kong, the aging population has become increasingly vital, with relaxed eligibility criteria enabling more elderly individuals to donate. While this inclusivity helps stabilizing the blood supply, it also introduces challenges, as older donors may present with chronic conditions such as hypertension, hyperlipaemia, etc. Therefore, RNs must adapt their health assessment techniques to address these issues, ensuring donor safety and optimizing the donation process.

Malaria is transmitted to humans through the bite of infected female Anopheles mosquitoes. However, other forms of transmission can also occur through blood transfusions, organ transplantation, congenital pathway or work accident by contaminated needles4. Transfusion-transmitted malaria (TTM) is acquired via asymptomatic blood donors and takes place through blood elements transfusion from a malaria infected donor to a recipient who consequently might have several clinical symptoms, especially for immuno-compromised people5. An interesting point is that TTM involves blood with direct release of malaria parasites into the recipient's circulation, resulting in high-risk consequences. Considering important advances in molecular techniques, nucleic acid amplification tests (NAT) are essential to ensure blood safety with a sensitive detection of low-density malaria infections6. NAT may contribute to malaria reduction and represent an important strategy for its elimination, providing an epidemiological approach worldwide.