Asymptomatic carrier of Babesia spp. among blood donors - epidemiological situation in Poland.

Introduction: Babesiosis is caused by one of several Babesia species. In Europe, B. divergens predominates in humans, while in North America it is B. microti. Babesia spp. infection in donors with a disease-free course of infection can be a major problem in blood recipients. A recipient with impaired immune system functions is at risk of full-blown development of the disease. In Poland and in most countries of the world, blood donors are not routinely tested for Babesia spp. infection. In our previous study, we detected Babesia venatorum DNA in blood donors, which was the reason for expanding the study to include more test subjects.

Objective: The aim of this study was an attempt at estimating the prevalence of asymptomatic infection with Babesia spp. among blood donors from the Regional Centres for Blood Donation and Blood Treatment in Warsaw and Wrocław.

Materials and methods: The material for the study was whole blood from regular blood donors from two Regional Centre for Blood Donation and Blood Treatment in Warsaw and Wrocław. Whole blood samples from 1,067 blood donors collected in June-July 2022 were analyzed. Blood collected directly from the donor during the blood donation procedure. All persons qualified by a doctor as a donor were selected for the study, regardless of age and sex. All subjects were informed in detail about the purpose of the study and gave their written consent. Isolation was made by using the Chelex 100 chelating resin, followed by the studying of the genetic material using the qPCR reaction. The results were analysed based on the amplification curve.

Results: The protozoan Babesia spp. was not detected in the blood samples.

Conclusions: The risk of blood-borne babesiosis is extremely low in Poland.