Pacheco's disease it is named after the Brazilian veterinarian, Genesio Pacheco, who first came across the disease in 1929, in an outbreak affecting the turquoise-fronted amazon parrot, "Amazona aestiva". Initially, Pacheco's disease was thought to be a manifestation of avian psittacosis. The causative agent of the disease, a herpesvirus, was not identified until 1975. Pacheco's disease Pacheco's disease is an acute and often lethal infectious disease in psittacine birds. The disease is caused by a species of herpesvirus, Psittacid alphaherpesvirus 1 (PsHV-1), which consists of four genotypes. Birds which do not succumb to Pacheco's disease after infection with the virus become asymptomatic
Psittacosis cases may occur that are not correctly diagnosed or reported. Bird owners, pet shop employees, zookeepers, and veterinarians are at risk of the infection. Some outbreaks of psittacosis in poultry-processing plants have been reported. In birds, "Chlamydia psittaci" infection is referred to as avian chlamydiosis. Infected birds shed the bacteria through feces and nasal discharges, which can remain infectious for several months. Many strains remain quiescent in birds until activated under stress. Birds are excellent, highly mobile vectors for the distribution of chlamydial infection because they feed on, and have access to, the detritus of infected animals of all sorts.