Thesis Welling Oei

On 21 June 2016 Welling Oei defended her thesis 'Modelling the risk of emerging infections for blood transfusion' at the University of Utrecht.

Promotores: Prof HL Zaaijer PhD, prof RA Coutinho PhD and prof MEE Kretzschmar PhD 
Co-promoter: MP Janssen PhD

The research for his thesis was conducted at the Julius Center for Health Sciences and Primary Care Utrecht University. The studies in this thesis were funded by Sanquin Blood Supply Foundation and partly by the European Centre for Disease Prevention and Control.


There is extensive documentation of transmission of a number of emerging infectious diseases (EIDs) through blood transfusion. This suggests that additional measures may be required in case an EID outbreak occurs. In order to determine whether to implement such steps, and which ones, an  assessment of the seriousness of this risk is needed. In blood transfusion safety, a generic model that is applicable to any EID, can be used for  a rapid assessment of the impact of an on-going outbreak specifically, is called for.

This thesis describes the development and application of models that quantify the risk posed by EIDs for blood safety. The first model allows the ranking of the risk of blood transmissible infections as regards their potential threat to transfusion safety. The second model, the European Up Front Risk Assessment Tool (EUFRAT), quantifies the transfusion transmission risk of an EID in two different scenarios: (1) transmissions by donors exposed to a local outbreak, and (2) transmission by donors returning from travels to an outbreak affected area. This latter model also allows evaluation of potential safety measures during EID outbreaks. We illustrated how the model is generally applicable to a number of outbreaks of EID with short infectivity (dengue, chikungunya) and presumed long infectivity (Q fever). To show how well the model performs we compared model estimates with data from an independent source. We also discuss how the model can be further enhanced to support decision making in transfusion safety.