Contaminated feces and aerosolized dust has been documented to transmit the virus. Chicks that have protective level of antibody from the yolk sac may infect susceptible chicks in the same nursery. Repeated finding of the virus in crop washings and feather samples from persistently infected adults that are clinically normal is responsible for continued spread of the virus in the aviary. Respiratory secretions have also shown virus so that breathing the air is all that is necessary in theory to transmit the disease. Virus shed from the kidney and reproductive tract are also probable.
Polyoma virus is resistant to many environmental conditions, disinfectants and heat.
Chlorine is effective in killing polyoma. Oxyfresh Gele at 4 tablespoons per gallon of water was proven by Dr. Branson Ritchie to kill polyoma virus. Violators of the closed aviary concept are the primary manner of introduction of disease into the aviary. Now you have a DNA probe test for polyoma, so surely this will not happen to your aviary. Birds found to be shedding the virus or are suspected should be isolated and managed separately from non shedders.