Chlamydophila psittaci in birds and humans: study of an emerging zoonosis

Abstract

Nowadays zoonoses comprises the majority of the emerging infectious diseases, which occurrence varies according to biological, environmental and socio-economic and cultural factors. Regarding the cultural factors, the maintenance of companion animals in Brazil is increasing significantly. According to the Associação Brasileira da Indústria Pet, the National Pet Commerce is a booming market and has already reached the second highest turnover worldwide, representing 0.4% of GDP. It is noteworthy that the popularity of wild species is also growing, as an example, currently 19 million birds are kept as pets in Brazil. However, these animals may have an important role in the spread of pathogens with zoonotic potential, such as Chlamydophila psittaci, the etiological agent of chlamydiosis in birds and psittacosis in humans. The Psittaciformes (parrots, parakeets, macaws, cockatiels, etc.) are the main Order of birds affected by C. psittaci, and is also the main Order kept as pets. In recent years, several studies have shown that clamidiosis is an endemic disease in Brazil, nevertheless, there are few studies assessing the zoonotic potential of this pathogen. In humans, psittacosis typically causes influenza-like symptoms, and can lead to severe atypical pneumonia; nonetheless, due to the difficulties related to laboratory diagnosis and the relative unfamiliarity of the disease by health professionals, its incidence in the country is still unknown. In general, the atypical pneumonias represent 15% of community-acquired pneumonias and in such cases, the determination of the pathogen is crucial for the success of the treatment and for the patient's survival. Thus, the present study aims to estimate the occurrence of C. psittaci in patients from the Instituto Emílio Ribas de Infectologia with atypical pneumonia and determines the epidemiological link with birds and the risks factors associated, therefore evaluating the role of psittacosis as a potential emerging zoonosis. Then, paired samples of blood from the patients with clinical suspicion of psittacosis will be collected for the investigation of anti-C. psittaci antibodies. In addition, biological samples from every species of bird related to these cases will be collected for survey and molecular characterization of C. psittaci's genome. For epidemiological research and analysis of the risk factors extensive questionnaires, regarding the avian hosts and the humans patients, will be performed. Statistical analysis of these data will be held with the program Epi Info. The present study will allow a greater understanding of this zoonosis in Brazil and its real impact on human health, it will also provide the basis for establishing more specific prophylactic measures related to birds and humans, reducing future risks and mitigating the possible occurrence of outbreaks. (AU)