Molecular test for screening malaria-infected blood donors to maximise recipient safety in Acre State, a Brazilian endemic area.

Abstract

Background: Although blood transfusion is an essential therapeutic procedure, it can present risks, including transmitting infectious diseases, such as malaria. In Acre, the thick blood smear microscopic examination (TBS) is used to screen infected malaria blood donors. However, TBS has low sensitivity for detecting Plasmodium in situations of low parasitaemia, such as those presented by asymptomatic clinically healthy individuals.

Objectives: To investigate the pertinence of using polymerase chain reaction (PCR) to detect malarial infection for screening blood donors in Cruzeiro do Sul, Acre, an endemic high-risk malaria area in the Legal Amazon.

Methods: A cross-sectional study was conducted among individuals eligible and ineligible to be blood donors, according to clinical and epidemiological criteria. Besides the mandatory screening of HCV, HBV, and HIV tests, malaria PCR and TBS were also carried out on all blood donor candidates who attended the Cruzeiro do Sul Blood Centre from July to September 2022.

Findings: Of the 230 participants, 209 (91%) were eligible for blood donation by clinical-epidemiological screening. Surprisingly, no blood donor candidate reported a history of malaria. All TBS microscopic tests were negative at the time of recruitment. However, samples from four blood donor candidates (two eligible by clinical and epidemiological malaria criteria and two ineligible by hypertension and recent tattoo) were positive by Plasmodium and P. vivax molecular tests.

Main conclusions: Malaria molecular techniques for screening blood donors should be introduced in the Brazilian Blood Centres to maximise recipient safety. Furthermore, selecting zero-risk donors could pave the way to build a transmissible malaria-free environment in the blood bank context in the near future.