Comprehensive monitoring
Numerous measures ensure against the transmission of dangerous diseases via donated blood. Nevertheless, there is always some residual risk.
To keep the risk of the transmission of dangerous diseases via transfusions as low as possible, blood donors must meet eligibility criteria and provide information in a detailed questionnaire relating to various safety aspects, such as their state of health, travel in risk areas and sexual behaviour. These eligibility criteria were relaxed somewhat as of 1 July 2017, after Swissmedic, the authority with oversight in this area, approved a request from Swiss Transfusion SRC. Under the new rules, men who have had sex with men (MSM) can donate blood if they fulfil the donation eligibility requirements and have not had homosexual sexual contact for a period of one year. However, Swiss Transfusion SRC’s longer-term aim is for a nuanced assessment of the risk behaviour of all blood donors.
Highly sensitive tests
Every unit of donated blood undergoes very detailed screening tests. As a result, two HIV-positive units of donated blood were detected and destroyed in time in 2017 (2016: 4). This figure has been somewhere in the two to six range for the past ten years. Twelve donations infected with hepatitis C were detected in time last year (2016: 12). These figures have fluctuated between 8 and 24 over the last 10 years. A total of 39 units of donated blood infected with hepatitis B were detected and destroyed in 2017 (2016: 45). Extraordinarily sensitive tests for hepatitis B have been in use since 2015, making Switzerland one of the leading countries in this respect.
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
Tropical pathogens on the radar
Infectious tropical diseases, like the West Nile, dengue, chikungunya or Zika virus, continued to be a focus in 2017. These diseases can be transmitted via blood transfusions. Blood donors who have travelled in “risk areas”, are subject to a deferral period before their next blood donation. Viruses may be present in their blood even if they have not noticed any symptoms. Donors may develop symptoms only after a certain period, or their immune system may be fighting the virus without showing any symptoms of disease. The deferral periods after travel take these facts and others into account. Risk areas can change very quickly, making it necessary
to modify policies or eligibility criteria for blood donation. Swiss Transfusion SRC engages in constant, comprehensive monitoring in this area, using input from numerous national and international sources. These include the FOPH bulletin, including the travel-related medical recommendations, and information from Tropimed, the European Center for Disease Control and the Emerging Infectious Diseases Monitor of the European Blood Alliance. The monitoring allows the organisation to react swiftly to changing conditions and ensures that it is prepared when new tropical pathogens appear in regions or countries.
