A simulation model to estimate the risk of transfusion-transmitted arboviral infection.

Background: The arboviruses West Nile virus (WNV), dengue virus (DENV) and Ross River virus (RRV) have been demonstrated to be blood transfusion-transmissible. A model to estimate the risk of WNV to the blood supply using a Monte Carlo approach has been developed and also applied to Chikungunya virus. Also, a probabilistic model was developed to assess the risk of DENV to blood safety, which was later adapted to RRV. To address efficacy and limitations within each model we present a hybrid model that promises improved accuracy, and is broadly applicable to assess the risk of arboviral transmission by blood transfusion.

Material And Methods: Data were drawn from the Cairns Public Health Unit (Australia) and published literature. Based on the published models and using R code, a novel 'combined' model was developed and validated against the BP model using sensitivity testing.

Results: The mean risk per 10,000 of the combined model is 0.98 with a range from 0.79 to 1.25, while the maximum risk was 4.45 ranging from 2.62 to 7.67 respectively. These parameters for the BP model were 1.20 ranging from 0.84 to 1.55, and 2.86 ranging from 1.33 to 5.23 respectively.

Conclusion: The combined simulation model is simple and robust. We propose it can be applied as a 'generic' arbovirus model to assess the risk from known or novel arboviral threats to the blood supply.