The Pathology of Respiratory Viral Co-Infections in a Murine Model

The pathology of single respiratory viral infections is well known but the effects of co-infection by two viruses, which commonly occurs in humans, remains unclear. By determining if rhinovirus (RV) enhances or reduces disease severity during infection of mice by PR8, an influenza virus, we will better understand how co-infection affects pathology and disease severity. We infected BALB/c mice with either a mock or RV and two days later, with either a mock or high or low dose of PR8. The mice were monitored for morbidity and mortality. Tissues from the upper and lower respiratory tracts were collected, processed, stained, and imaged with optical microscopy. Using ImageJ, the densities of neutrophils, macrophages and lymphocytes in image sections were measured. These data will be used to compare the pathology and determine whether RV helped the host recover more quickly, or whether it exacerbated the severity of PR8 infection. These findings will provide insight into the interactions between unrelated respiratory viruses during co-infection that regulate pathology and disease severity