Risk factors associated with Chlamydia psittaci infection in psittacine birds.

Chlamydia psittaci is the aetiological agent of chlamydiosis in birds, especially Psittaciformes. The objective of the present study was to detect C. psittaci by means of semi-nested PCR among psittacine birds sold at pet markets and kept as pet birds in Salvador, Bahia, Brazil. Questionnaires were used to identify risk factors involved in the epidemiology of the disease. In addition, the management of birds and cages was observed at each location studied. The frequency of C. psittaci infection was 10.6% (33/311) in the psittacine birds studied. Birds kept in households were less frequently positive (3.4%; 5/148) than those at pet markets (17.2%; 28/163). Among the several factors analysed in the epidemiology of the disease, only population density (P = 0.001) and cage hygiene (P = 0.041) in birds at pet markets were significantly associated with C. psittaci infection. These results demonstrate the presence of C. psittaci infection in Psittaciformes kept as pets and held at pet markets in Salvador, Bahia, showing that this micro-organism is a public health concern. Control measures should be encouraged to prevent the spread of the agent among birds, as well as among employees and customers.