Prevalence and genotypes of Chlamydia psittaci in pet birds of Hong Kong

Abstract

<p>Psittacosis, or parrot fever, is a zoonotic disease caused by <em>Chlamydia</em> species associated with birds. One of the causative agents of the disease is <em>Chlamydia psittaci</em>, which is commonly carried by psittacine and other bird species, can be highly pathogenic and virulent to humans. In Hong Kong, a city with high population density, psittacosis is a notifiable disease with over 60% of cases in the last decade resulting in hospitalization. However, the sources of transmission of <em>C</em>. <em>psittaci</em> and its prevalence in pet birds in Hong Kong are currently unknown. To evaluate the risks of psittacosis transmission through pet birds, we tested the presence of <em>C</em>. <em>psittaci</em> and determined its genotypes in samples obtained from 516 captive birds from households, pet shops, and a veterinary hospital in Hong Kong. Results revealed that five samples (0.97%), collected from budgerigars and cockatiels, were <em>C</em>. <em>psittaci</em>-positive, while four (80%) of them were obtained from pet shops. Our phylogenetic analysis revealed that all identified strains belonged to Genotype A and showed high similarity to other sequences of this genotype obtained from various geographical locations and host species, including mammals. Our findings provide evidence for the presence of <em>Chlamydia psittaci</em> and shed light on its sources in captive birds in Hong Kong. They highlight the potential zoonotic risks associated with this pathogen, which can affect both humans and wild birds.<br></p>