Clinical and molecular diagnosis of Chlamydophila in captive parrots in Pará State, Brazil

Abstract

Parrots (Order Psittaciformes) are globally distributed birds that, together with members of the Columbiformes, represent the most susceptible animals, in regards to infection by Chlamydophila psittaci, which is an obligate, zoonotic, intracellular bacterium that causes chlamydiosis in domestic and wild birds and psittacosis in humans. The aim of the present study was to assess the occurrence of C. psittaci in Brazilian psittacids kept in conservation breeding sites in Pará State, Brazil. Cloacal and oropharynx swab samples were collected from 201 psittacids that were distributed among four breeding sites: Metropolitan Area of Belém (C1 and C2), Northeastern Pará (C3), and Low Amazon (C4). The samples were screened for C. psittaci using semi-nested PCR, and the resulting incidence data were analyzed using proportion and chi-square tests. Chlamydophila infection was confirmed for all the breeding sites, with an overall prevalence of 31.84%, and no species-specific predisposition was observed. Furthermore, 13.93% of the sampled birds eliminated the infectious agent by the cloaca, whereas 11.44% eliminated the agent by the oropharynx, and 6.47% eliminated the agent by both routes. Moreover, there was a significant difference between the incidence of Chlamydophila infection of breeding sites C2 and C3 (p=0.029), which yielded the smallest and largest number of diagnosed cases, respectively. In the present study, most of the birds (27.86%) were considered unapparent carriers of Chlamydophila infection, and only 3.98% of the birds yielded both a positive diagnosis and clinical signs of chlamydiosis.