The program in the Parrish laboratory has been concerned with the analysis of viruses that emerge in new hosts to cause epidemics of disease. We are interested in gaining a complete understanding of the processes, so have worked on aspects that range from the molecular interactions of viruses with host factors, to the tissue and host tropism, virus evolution, and transmission and epidemiology. We use multidisciplinary approaches to this work, including studies of the viruses in nature and in the laboratory.In addition, we work on defining the fundamental and general aspects of viral emergence processes that are shared by many different emerging viruses (as well as by other pathogens including bacteria and parasites).
We are examining three main models: (1) the emergence of canine parvovirus (CPV) in 1978 to cause a pandemic of disease in dogs, (2) the H3N8 canine influenza virus (CIV) that arose around 2000 as a variant of the equine influenza virus (EIV) and which spread through much of the USA for 16 years, and (3) the H3N2 CIV which emerged in 2005 as a variant of an avian influenza virus in China and spread to the USA in early 2015, where it has been causing periodic outbreaks.
We are interested in understanding the properties of the virus:host interactions that control host ranges. One of the areas we are focusing on is the interactions of the viruses with the host cell receptors – because parvoviruses interact with transferrin receptor type-1 is clearly a control of host range, the interactions of influenza viruses with specific modified forms of sialic acid control infection in a specific host-specific manner. On example is shown below, and that is the emergence and variation of the CPV and its subsequent early variation in dogs.