In the context of public health, this study underlines the dynamics of infection spread and how co-infections can worsen an outbreak. The results also suggest prevention of simultaneous co-infection is not as important as preventing co-infection regardless of timing. Granted, prevention of any infection is ideal. But when one does show up, such as influenza, gastroenteritis, or HIV, we should do all we can to prevent secondary infections. If not, we may find an epidemic can quickly go from manageable to uncontrollable.