Polyoma Virus (APV)
Positive: A positive blood sample confirms active infection, usually clinical. Most young (up to 14 weeks) of susceptible species die shortly after exhibiting clinical signs (4-12 hours). Older birds and non-susceptible species may exhibit no clinical signs, reverting to a negative, naturally protected state. Retesting with a blood sample in 60 to 90 days to confirm negative status is suggested.
Low Level Positive: LLPs confirm infection, but at a lower level. Many LLPs are previous exposures, with immune systems that are actively processing the virus. Most progress to a negative, naturally vaccinated state. They may intermittently shed virus during this stage and should be housed accordingly. Retesting with a blood sample in 45 to 60 days is necessary to confirm these animals are not carriers.
Negative: Negative results confirm no organism present at time of testing.
Swab Sample — Combined choanal/cloacal swab
Positive: Positive swabs confirm virus presence, but do not reflect clinical or sub-clinical infection. They are shedding virus, and appropriate care must be taken. Most will revert to a negative status. Retest with a blood sample in 45 to 60 days to ensure a negative status has been achieved.
Low Level Positive: Virus is detected at a low level. Most are not clinical, but are actively shedding. Care must be taken when housing. Retest with a blood sample in 45 to 60 days to ensure a negative status has been achieved.
Negative: A negative swab only confirms no organism is being shed at the time it was taken. It will not reflect a current status of infection or a carrier state which may intermittently shed virus.
Specimen of Choice: Blood
A blood sample is definitive for infection status. Positive birds may be negative on swab, as swabs can only detect current shedding activity. Environmental exposures may test positive by swab.
Swabs from liver and other organs provide the best samples. These swabs are excessively "hot," confirming disease.
Procedure is the same for all organisms (see above).