The network structure of host-virus communities in bats and rodents

Background/Question/Methods

Most emerging infectious diseases are zoonotic (passed from animals to humans), and >70% of these originated in wildlife and have been increasing over time. Cross-species transmission is one of the most challenging and hence least studied aspects of disease ecology, yet it is the defining process in zoonotic disease dynamics. Bats are the natural reservoirs of many important zoonotic viruses, and this has led to the speculation that bats may be special as reservoirs. Here, we use a novel network approach to try to identify ecological and biological correlates of cross-species virus transmission in bats and rodents, another important host group. I create networks that connect host species via their shared viruses and examine differences in overall properties of the bat and rodent viral sharing networks. Next, I examine the biological and ecological correlates of the number of viruses two host species will share. Using network metrics, I identify distinct communities of viral sharing, potentially important reservoir species, and traits associated with these species.

Results/Conclusions

I show that viruses are more often shared among bat species than among rodents, suggesting viruses may pass more easily through the bat network. Frugivory was an important predictor of viral richness in bats. Colony size was important predictor of viral sharing (degree), and migration was an important may be an important predictor for spreading viruses to new communities (betweenness). I identify distinct communities of viral sharing among bats, which can help explain some anomalies between in the global distribution of viral richness in bats.