The watchword for blood donation: safety

Swiss Transfusion SRC strives to ensure a high standard of safety for donors and patients. One way it does so is by regularly monitoring the effects of viral and other pathogens that might be transmissible by blood.

Standardisation of blood donation criteria

As of 1 November 2023, the same eligibility criteria apply for all potential donors in Switzerland and thus irrespective of sexual orientation. Thus, the requirement that male donors wait 12 months after having sexual contact with another man before donating blood no longer exists.

The introduction of the new policy followed the issue of a report reassessing risks under current conditions prepared over the past two years by Swiss Transfusion SRC and an expert group. On 24 July 2023, Swissmedic, the agency responsible for licensing and monitoring the use of therapeutic and medicinal products, approved the request for the standardisation of donor eligibility criteria.

The standardisation of the eligibility criteria can be expected to result in an additional benefit: improved traceability through the blood donors. Moreover, the elimination of the question concerning sexual orientation simplifies the eligibility review process for staff and blood donors.

Highly sensitive tests for donated blood

One HIV-positive sample was detected in 2023 (2022: 2) in the screening tests performed on every unit of blood donated. The number of infected units has ranged between zero and four for the past ten years. Three donations infected with hepatitis C were detected in time last year, one fewer than in 2022. Testing for hepatitis B (HBV) resulted in the detection and destruction of a total of 25 infected donations in 2023 (2022: 28). Another 55 cases of Hepatitis E were detected in the context of blood donation as well (2022: 45). An increase in the number of units (72) infected with human parvovirus B19 was observed (2022: 1). We assume that face masks protected people against infection during the coronavirus pandemic, as the virus is transmitted by infected respiratory droplets and that the lifting of the mask mandate enabled parvovirus B19 to spread more easily again.

Tropical pathogens

Swiss Transfusion SRC monitors the incidence and distribution of blood-borne diseases. When necessary, the organisation defines risk areas and takes steps to keep the blood donors and patients safe. For instance, individuals returning from travel to a risk area are required to wait for a certain period before they can donate blood. The waiting period is normally one month.

Numerous cases of West Nile virus were reported in Europe once again in 2023. As in previous years, most of the cases of this mosquito-borne disease that appeared in Europe did so in Eastern Europe, Italy, France, Spain and Germany in the summer. The spread of the West Nile virus among animals and humans was carefully monitored in 2023. The virus was detected in previously unaffected regions in France and Spain. No autochthonous (locally acquired) infections of residents of Switzerland were reported, but the situation in the country was closely monitored. Swiss Transfusion SRC has been preparing for the possible appearance of the West Nile virus in animals and humans for several years now and has developed an action plan for this event. The Swiss blood transfusion centres can immediately test all blood donations using validated methods if needs be.

The number of dengue cases reported in Europe has also been on the rise in recent years, particularly in Italy and France. Eight regions in Southern France were defined as risk areas in 2023 (2022: 6 regions) as were 3 regions in Italy (no regions affected in 2022). Swiss Transfusion SRC has also prepared an action plan for use in the event of the appearance of the dengue virus in Switzerland.

No infections with the Zika virus were detected anywhere in Europe in 2023, as was also the case in 2022.

Projects focussing on blood product safety

Swiss Transfusion SRC is committed to ensuring a high standard of safety for both patients and donors.
Two research projects funded by the SRC Humanitarian Foundation that were devoted to this same purpose were completed.

One was a six-year project examining a new method for measuring the cellular immune response to the hepatitis B virus. The aim is to better protect the recipients of blood and stem cell donations whose immune systems are weakened.

The other project was a three-year project aimed at identifying the test that is most efficient and best suited for detecting SARS CoV-2 antibodies in order to determine the seroprevalence (frequency of specific antibodies indicating a present or past infection with a disease in blood serum) of those antibodies among blood donors throughout Switzerland.

The results of this study attracted national and international attention. For Swiss Transfusion SRC, one important piece of information that emerged from the study was that blood donation was safe for both staff and donors during the pandemic, at first due to the protective measures in place, and later thanks to the presence of antibodies in donors’ blood.

Hepatitis C positive blood units detected in time
First-time donorsRegular donors

Hepatitis B positive blood units detected in time
First-time donorsRegular donors

HIV-positive blood units detected in time
First-time donorsRegular donors

HEV-positive blood units detected in time
First-time donorsRegular donors