MINOR RESPIRATORY ILLNESSES CAUSED BY AN AGENT OF THE PSITTACOSIS/LYMPHOGRANULOMA-VENEREUM GROUP

Current knowledge on Chlamydia pneumoniae, strain TWAR, an important cause of pneumonia and other acute respiratory diseases

This article reviews current knowledge of Chlamydia pneumoniae strain TWAR, a newly recognized Chlamydia organism that causes acute respiratory infection, especially atypical pneumonia. Information is included on the microbiology, classification and laboratory diagnosis of the organism. Details of a series of studies of both endemic and epidemic respiratory infections are reviewed to present information on both the clinical and epidemiological characteristics of infection with strain TWAR. Laboratory studies of antibiotic sensitivity and recommendations for treatment are presented.

An outbreak of psittacosis in a boys' boarding school

In 1980, an outbreak of a mild illness involving twenty pupils and four adults in a boys' boarding school was identified serologically as psittacosis. Intensive epidemiological investigations did not uncover the source. It is suggested either that sources of chlamydia other than avian exist, which may produce a milder illness than the avian type, or that human-to-human spread of a mild form of chlamydiosis occurs.

The incidence of Chlamydia psittaci antibodies in patients with respiratory tract diseases

The incidence of Chlamydia psittaci infections in Hamburg has been studied using the complement fixation test on 655 human sera collected from patients with respiratory tract diseases. Of the 653 sera investigated, 78 (11.9%) showed antibody titers between 1:8 and 1:128. Of the positive sera, 21 (16.9%) presented values of greater than or equal to 1:32. This infection is encountered more often in individuals over 21 years of age (15.9% to 23.4%) than in persons under 20 (0.8% to 6.0%). General practitioners' attention must be drawn to Chlamydia psittaci infections, since they seem to be of greater importance in human pathology than is generally assumed.

Pericardial and myocardial disease associated with serological evidence of infection by agents of the psittacosis-lymphogranuloma venereum group (Chamydiaceae)

Nine patients with acute pericarditis or myocarditis, or both, were found to have serological evidence of concurrent infection by a psittacosis agent. Three patients had conclusive epidemiological and clinical evidence of complicating pulmonary psittacosis and demonstrated that psittacosis agent does produce inflammatory heart disease in this geographic area.

Six patients had imperfect corroborative evidence of psittacosis and their clinical manifestations were atypical. Indeed, half of these patients were initially believed to have some form of idiopathic myocardial disease. Studies of these patients suggest that psittacotic infection m ay be causal in certain forms of heart disease commonly designated primary myocardial disease.