ECDC Review Identifies 77 Cases of Arbovirus Transmission Through Substances of Human Origin Between 2000 and 2025

The European Center for Disease Prevention and Control (ECDC) identified 77 documented global cases of probable or confirmed transmission of selected arboviruses through substances of human origin (SoHO) in a scoping review, which covered publications from January 2000 through June 2025. ECDC conducted the review in response to increasing reports of locally acquired arbovirus infections in Europe.

The review identified SoHO transmission of West Nile virus (WNV), dengue virus (DENV) and Zika virus (ZIKV), but found no documented cases for chikungunya virus, Usutu virus or Crimean-Congo hemorrhagic fever virus.

Of the 47 WNV transmission cases identified, 45 involved transfusion of blood components, including platelets, red blood cells, plasma and granulocytes. Transfusion-related cases included untested units before institution of testing, a granulocyte transfused prior to reactive test results, and a mixture of minipool and individual NAT-negative tested components. One case involved hematopoietic stem cell transplantation and one involved breastfeeding.

The review identified 26 DENV transmission cases, including 23 through transfusion of blood components, two through hematopoietic stem cell transplantation and one through breastfeeding. Three of the four ZIKV transmission cases involved transfusion of platelets, while one involved breastfeeding.

The clinical significance of the individual transmissions was not included as part the scoping review.

ECDC will use the findings to support development of guidelines on preventing arbovirus transmission through SoHO under the European Union’s new SoHO regulatory framework.

Information for Blood Collectors

AABB’s emerging infectious disease fact sheets provide information on individual pathogens, including clinical characteristics, potential for transfusion transmission and possible interventions. The fact sheets are intended to inform collection facilities and transfusion services and do not establish standards or requirements.