Mice as potential carriers of infectious bursal disease virus in chickens

To investigate the role of mice as potential carriers of infectious bursal disease virus (IBDV), three mice were inoculated with a very virulent strain of IBDV and allowed to have contact with three uninoculated mice. Faeces, intestine and pooled liver and spleen collected from inoculated mice 12 and 24 h post-inoculation were positive for IBDV by reverse transcriptase-polymerase chain reaction (PCR)-nested PCR (RT-PCR–nPCR). IBDV was detected by RT-PCR–nPCR in 3/3 samples of intestine and 2/3 samples of pooled liver and spleen from uninoculated in-contact mice at 24 h after exposure. Chickens developed clinical signs of IBD and died when inoculated with faecal extracts prepared from mice 24 h after inoculation with IBDV. Bursae were atrophied and positive for IBDV by RT-PCR–nPCR.