It should be stressed that association does not necessarily imply causation, and a variety of associative relationships between viruses and a given disease stat

It should be stressed that association does not necessarily imply causation, and a variety of associative relationships between viruses and a given disease state are possible. For instance, virus abundance might simply be an epiphenomenon reflecting bacterial host abundance, the human genetics that predispose people to a disease might also provide a more favorable environment for the virus or its bacterial host, the external causes of a disease may create a more favorable environment for the virus, or the virus may contribute to the disease presentation in some way but ultimately does not cause the disease in isolation from other important factors. Verifying the associations we have detected with independent studies of the same diseases in additional populations will be key to understanding the extent to which the findings presented here are generalizable.