Avian Chlamydiosis

Abstract

Recent findings in research on avian chlamydiosis include an increase in the reported prevalence of Chlamydia (C.) psittaci in poultry flocks, detailed descriptions of molecular processes governing the course of infection in vivo, as well as the discovery of new chlamydial species. Here we review the major advances of the last 6 years. In particular, we suggest that the observed re-emergence of C. psittaci infections in domestic poultry are due to a reduction in the use of antibiotics and better diagnostic assays. Cellular and animal models have significantly contributed to improving our understanding of the pathogenesis, including the events leading to systemic disease. The elucidation of host-pathogen interactions revealed the efficiency of C. psittaci in proliferating and disseminating despite the action of pro-inflammatory mediators and other factors during host immune response. Finally, the recent introduction of C. avium and C. gallinacea sheds new light on the epidemiology and aetiopathology of avian chlamydiosis.

Identification of Chlamydia gallinacea in a parrot and in free‐range chickens in Australia

“…At least two other Chlamydia species are known to infect birds: Chlamydia psittaci and Chlamydia avium . The most well‐known is C. psittaci , which primarily infects birds, but can also cause severe respiratory disease in humans, called ‘psittacosis’ . C. psittaci commonly infects parrots, but can also infect many other bird species .…”

“…The most well‐known is C. psittaci , which primarily infects birds, but can also cause severe respiratory disease in humans, called ‘psittacosis’ . C. psittaci commonly infects parrots, but can also infect many other bird species . C. psittaci may cause no clinical signs in birds, but it can have acute and chronic effects and has previously caused disease outbreaks on poultry farms .…”

“…C. psittaci commonly infects parrots, but can also infect many other bird species . C. psittaci may cause no clinical signs in birds, but it can have acute and chronic effects and has previously caused disease outbreaks on poultry farms . In chickens, it may cause reduced egg production and weight loss .…”

Outbreak of psittacosis in a group of women exposed to Chlamydia psittaci-infected chickens

“…Avian strains of C. psittaci are currently divided into 13 genotypes of the outer membrane protein A (OmpA), designated A to F, E/B, 1V, 6N, MatI16, R54, YP84, CPX0308 [5]. A degree of host specificity can be noted, with genotype A being detected mostly in psittacines, B and E in pigeons, or C and E/B in ducks [6].…”

Узагальнення Інформації Щодо Хламідійних Інфекцій Тварин Та Їх Зоонозного Потенціалу

“…Зооонози, що пов'язані з C. psittaci, можуть мати безсимптомний перебіг, або призводять до тяжких системних захворювань, пневмонії, міокардії, енцефалітам [37,41,55,60]. Досить рідкісна, але ж не виключена, безпосередня передача збудника від людини до людини та безпосередня передача серед інших видів савців [15,61,81] (табл. 3).…”