Network analysis of host–virus communities in bats and rodents reveals determinants of cross-species transmission

Luis, Angela D.; O'Shea, Thomas J.; Hayman, David T. S.; Wood, James L. N.; Cunningham, Andrew A.; Gilbert, Amy T.; Mills, James N.; Webb, Colleen T.

Several traits have been hypothesised to make bats particularly suited to hosting and transmitting viruses, including life history traits such as relatively long lifespans for their body size (Munshi-South & Wilkinson 2010) , which may facilitate viral persistence for chronic infections; their reliance on torpor, which can decrease viral replication and immune function (Dempster et al. 1966; Prendergast et al. 2002) ; and flight, which can facilitate transmission of viruses to new areas. In addition, many bat species are gregarious, living in dense aggregations, and some roosting sites can house diverse assemblages of bat species (Kunz 1982; Kuzmin et al. 2010) , which could facilitate transmission of pathogens and sustain acute-immunising infections. In evolutionary terms, bats are ancient mammals, and it has been hypothesised that viruses that evolved in bats may use conserved cellular receptors enhancing their ability to transmit viruses to other mammals (Calisher et al. 2006) . The diet of some species has been hypothesised to facilitate transmission of viruses; after feeding, frugivorous bats often leave partially eaten fruit behind which can be contaminated with viruses (Chua et al. 2002; Dobson 2005) . Bats are the second most diverse mammalian order with over 1100 species, with many overlapping species distributions; multiple regions across the globe are home to more than 40 bat species, allowing for species to interact and potentially spread viruses between them ( Fig. 1 ; Calisher et al. 2006; Luis et al. 2013) .