SARS-CoV-2 and Chlamydia pneumoniae co-infection: A review of the literature

Bacterial co-pathogens are commonly identified in viral respiratory infections and are important causes of morbid-mortality. The prevalence of Chlamydia (C.) pneumoniae infection in patients infected with SARS-CoV-2 has not been sufficiently studied. The objective of the present review was to describe the prevalence of C. pneumoniae in patients with coronavirus disease 2019 (COVID-19). A search in MEDLINE and Google Scholar databases for English language literature published between January 2020 and August 2021 was performed. Studies evaluating patients with confirmed COVID-19 and reporting the simultaneous detection of C. pneumoniae were included. Eleven articles were included in the systematic review (5 case cross-sectional studies and 6 retrospective studies). A total of 18 450 patients were included in the eleven studies. The detection of laboratory-confirmed C. pneumoniae infection varied between 1.78 and 71.4% of the total number of co-infections. The median age of patients ranged from 35 to 71 years old and 65% were male. Most of the studies reported one or more pre-existing comorbidities and the majority of the patients presented with fever, cough and dyspnea. Lymphopenia and eosinopenia were described in COVID-19 co-infected patients. The main chest CT scan showed a ground glass density shadow, consolidation and bilateral pneumonia. Most patients received empirical antibiotics. Bacterial co-infection was not associated with increased ICU admission and mortality. Despite frequent prescription of broad-spectrum empirical antimicrobials in patients with coronavirus 2-associated respiratory infections, there is a paucity of data to support the association with respiratory bacterial co-infection. Prospective evidence generation to support the development of an antimicrobial policy and appropriate stewardship interventions specific for the COVID-19 pandemic are urgently required.