Atypical pathogens and respiratory tract infections

Abstract

The atypical respiratory pathogens Chlamydia pneumoniae, Mycoplasma pneumoniae and Legionella pneumophila are now recognised as a significant cause of acute respiratory-tract infections, implicated in community-acquired pneumonia, acute exacerbations of chronic bronchitis, asthma, and less frequently, upper respiratory-tract infections.Chronic infection with C. pneumoniae is common among patients with chronic obstructive pulmonary disease and may also play a role in the natural history of asthma, including exacerbations. The lack of a gold standard for diagnosis of these pathogens still handicaps the current understanding of their true prevalence and role in the pathogenesis of acute and chronic respiratory infections.While molecular diagnostic techniques, such as polymerase chain reaction, offer improvements in sensitivity, specificity and rapidity over culture and serology, the need remains for a consistent and reproducible diagnostic technique, available to all microbiology laboratories.Current treatment guidelines for community-acquired pneumonia recognise the importance of atypical respiratory pathogens in its aetiology, for which macrolides are considered suitable first-line agents. The value of atypical coverage in antibiotic therapy for acute exacerbations of chronic bronchitis and exacerbations of asthma is less clear, while there is no evidence to suggest that atypical pathogens should be covered in antibiotic treatment of upper respiratory-tract infections. The term "atypical pathogen" most commonly refers to Chlamydia pneumoniae, Mycoplasma pneumoniae and Legionella pneumophila. Once believed to be of little clinical significance, a wealth of data accumulated over the past decade suggests that these are important respiratory pathogens in a wide range of respiratory-tract infections (RTIs) and are capable of causing severe, as well as mild-to-moderate, illness.Although the role of atypical pathogens [1], and of C. pneumoniae in particular [2], has been reviewed previously, there has been little focus on appropriate coverage of these pathogens in treatment decisions for patients with RTIs. In addressing this issue, this review examines the role of atypical pathogens in the aetiology of upper and lower RTIs, in both adults and children, and discusses the value of appropriate coverage of these pathogens in empirical antibiotic prescribing.

Role of Chlamydia pneumoniae in community-acquired pneumonia in hospitalized Jordanian adults

“…pneumoniae has consistently been recognized as a common cause of CAP. Between 1% and 22% of CAP cases have been attributed to this pathogen [13][14][15][16]18,34]. Clearly, frequency of acute infection (obtained here based on MIF) among CAP patients correlates well with available epidemiological data.…”

“…In the last two decades, C. pneumoniae has been recognized to play a role in the etiology of CAP worldwide. According to epidemiological studies, C. pneumoniae accounts for 1%-22% of patients suffering from CAP [13][14][15][16]. It has been suggested that this pathogen could play an etiological role for CAP in 6% of pediatric outpatients between 6 months and 12 years of age [17].…”

A clinically silent respiratory infection withChlamydophilaspp. in calves is associated with airway obstruction and pulmonary inflammation

“…The phenomenon of chronicity and persistence, however, is thought to be involved in the pathogenesis of chronic inflammatory airway diseases, i.e. human asthma and COPD, and even in pulmonary emphysema or lung cancer [2,3,14,19,22,26,50,51,56].…”

Mycoplasma Infection: Clinical Types, Variations of Clinical Course and Diagnostic Mistakes

“…При лечении макролидами следует учитывать возможность удлинения интервала Q-T, соблюдать осто-рожность при сочетании его с эуфиллином. Эффек тивность лечения заболеваний нижних дыхательных путей макро-лидами не вызывает сомнений, однако она должна быть обоснована и для болезней верхних дыхательных путей [6].…”

“…Нередок исход в хронический процесс -пневмоскле-роз, бронхоэктазы. F. Blasi считает хламидии и микоплаз-мы основными возбудителями, влияющими на развитие бронхиальной астмы [6].…”