The Impact of Contact Patterns of Sexual Networks on Zika Virus Spread: A Case Study in Costa Rica

The impact of Zika virus (ZIKV) is a global public health issue and its severity is ongoing. It is primarily transmitted via mosquitoes and sexual contacts. Sexual transmission experiences a longer period and strongly depends on the topological structure of sexual networks. However, relatively little work has been done to explore the characteristics of ZIKV infection in sexual networks, and further control ZIKV by changing contact patterns between individuals. In this paper, using the settings of Costa Rica as a case study, we developed a heterosexual network-based model, to study the effect of changing the degree heterogeneity by the measure of deleting the sexual contacts of individuals with small number but large degree in the sexually active places at different time, on ZIKV spread. We obtained a threshold time, which is later than the peak time of ZIKV infected cases. If applied prior to the threshold time, the measure will inhibit ZIKV infection and lower the final size; surprisingly if past the threshold time, the measure will boost ZIKV infection and increase the final size. In addition, our model yielded higher cumulative infection among females, which is in line with observations. Our results provide some guidelines for preventing and controlling mosquito-human and sexual transmissions against ZIKV, particularly for countries with a high rate of sexually transmitted infections.