Psittacosis: An Underappreciated and Often Undiagnosed Disease

Abstract

The bacterial agent Chlamydia psittaci, and the resulting disease of psittacosis, is a little-known and underappreciated infectious disease by healthcare practitioners and in public health in general. C. psittaci infections can cause significant psittacosis outbreaks with pandemic potential, with person-to-person transmission being documented in the last decade. In this publication, we review the pathogen and its disease, as well as examine the potential for genetic manipulation in this organism to create a more deadly pathogen. Recent disease surveys indicate that currently, the highest incidences of human disease exist in Australia, Germany and the UK. We recommend the universal public health reporting of C. psittaci and psittacosis disease and increasing the promotion of public health awareness.

Detection of Chlamydia psittaci in the Genital Tract of Horses and in Environmental Samples: A Pilot Study in Sardinia

“…Rare complications could include myocarditis, encephalitis, hepatitis, keratoconjunctivitis, acute respiratory distress syndrome, and multiple-organ failure, with development of ocular lymphoma [ 8 ]. Serious or life-threatening illness can occur when the signs of psittacosis are not recognized [ 9 , 10 ]. The main route of human infection is by the inhalation of aerosolized organisms from dried avian feces or respiratory tract secretions of infected birds [ 11 ].…”

“…Moreover, although C. psittaci is an obligate intracellular bacterium, it has been documented in environmental samples and waters as reticulate bodies that may represent a long-term environmental reservoir of the bacterium [ 9 ]. Although previous studies in infected mares reported reproductive (such as genital infection, occasional abortion, and infertility) and respiratory signs (pneumonia, conjunctivitis, and polyarthritis) attributed to C. psittaci [ 18 , 19 ] and rarely to C. abortus , the relationships between equine abortion and chlamydial infection are still being studied [ 20 ].…”

Editorial: Chlamydia-host interaction and its pathogenic mechanism

“…Among the Chlamydiaceae family, the genus Chlamydia contains 13 species ( LPSN, 2024b ), 3 of which are the most relevant as human pathogens. Chlamydia trachomatis is the main bacterial cause of sexually transmitted infections and the leading agent of infectious blindness worldwide ( WHO, 2018 ; WHO, 2022 ), C. pneumoniae is a common etiology of atypical pneumoniae ( Aliberti et al., 2021 ), and C. psittaci causes psittacosis, a globally distributed and potentially fatal zoonotic disease transmitted to humans mainly by exposure to birds ( Dembek et al., 2023 ; Liu et al., 2023 ).…”