Reoviruses (rotaviruses and reoviruses)

Rotaviruses (RVs) and reoviruses are ubiquitous. RVs are a major cause of diarrhea in neonatal and young pigs. However, the association of reoviruses with pig disease is unclear since reoviruses have been found in both healthy pigs and those with respiratory, enteric, and reproductive disease. RVs are a major cause of diarrhea in humans and animals, including pigs. RV infection ranges from subclinical to severe clinical disease, depending on the RV strain, the age of the pig, immune status, overall herd health, and the presence of secondary bacterial or viral infections. RV infections are endemic in swine populations, and elimination and eradication from swine herds is not practical. Instead, the aim is to minimize the impact of RV infections by reducing mortality and the incidence of diarrhea. Maintaining maternal immunity is key to achieving these aims. RV infections stimulate both systemic and local immunity, but virulent RV strains elicit stronger immune responses than attenuated strains.