Persistent and recrudescent infection in cattle following natural infection with Middle Point orbivirus.

Middle Point orbivirus (MPOV) is a recently described Australian arbovirus, related to Yunnan orbivirus from China. Analysis of genetic variation within the major serotype gene of MPOV isolates collected from sentinel cattle has identified eight co-circulating strains. The pattern of strain isolation from individual animals during the study period was consistent with an interpretation of persistent MPOV infection of up to five months, featuring episodes of quiescence (below levels required for virus isolation) followed by viral recrudescence. This is significant with regard to current interpretations of infection, persistence and recrudescence during natural infections of orbiviruses, including bluetongue virus.