Demonstration of bovine respiratory syncytial virus RNA in peripheral blood leukocytes of naturally infected cattle.

RNA of Bovine respiratory syncytial virus (BRSV) was found in peripheral leukocytes and nasal mucosa of infected cows by nested reverse transcription-polymerase chain reaction (nRT-PCR). We suppose that this finding obtained in the convalescent phase of infection indicates possible persistence of the virus in cells of the immune system.