However, all age groups should be considered susceptible to circovirus infection. Prognosis Spontaneous recovery from acute PBFD can occur in many species, including budgerigars, lorikeets and lovebirds. Some acutely affected birds also recover. However, the majority of chronically affected birds do not recover from the disease. Infection is probably maintained in a population by diseased birds.
Epidemics can occur in susceptible wild or aviary flocks.
Virus transmission is probably predominantly by horizontal spread but carrier birds may contribute by vertical transmission. Virus infectivity probably persists in contaminated nests for many months or years. PBFD in aviary birds Aviary flocks with a history of PBFD usually have a high seroprevalence. Aviculturists should be advised to maintain a closed flock or purchase birds from PBFD-free flocks and to breed birds in quarantine. PBFD is difficult to quarantine.