COVID-19 infection is known to be associated with a wide range of clinical manifestations, including severe pneumonia. Those affected may exhibit symptoms such as fever, cough, fatigue, and difficulty in breathing. In severe cases, pulmonary symptoms may resemble sepsis and septic shock, caused by both direct viral invasion and an immune-mediated response known as a ‘cytokine storm’.1,2 The associated lung pathology may be reflective of viral-induced injury, bacterial superinfection (secondary bacterial infection in SARS-CoV-2-infected patients), or immune-mediated endotheliitis and microthrombosis.3,4
During outbreaks of ‘severe acute respiratory syndrome’ (SARS) and ‘Middle Eastern respiratory syndrome’ (MERS), researchers demonstrated a correlation between respiratory viral infections and bacterial and fungal superinfection.5 However, data are limited on the prevalence and severity of bacterial and fungal superinfections in relation to COVID-19 infection. Currently, empiric antibacterial therapy is commonly administered to patients with severe COVID-19 in an effort to prevent or treat bacterial coinfection or superinfection. However, the true frequency of bacterial coinfection has been subject to debate, particularly in the context of its implications for antimicrobial resistance development.
In a recent retrospective analysis, Liu and colleagues studied patients with COVID-19 pneumonia requiring intubation (n=165), who were admitted to a community hospital system in the United States between March 1 and May 1, 2020.5 At intubation, 87.3% (n=144) of the patients were initiated with empiric antimicrobials directed at potential bacterial coinfection. The medical records of the recruited patients were reviewed, and sputum samples were evaluated for bacterial and fungal growth.5 The primary objectives of the study were to determine the frequency of culture positivity and to identify risk factors and outcomes associated with positive cultures. In addition, the timing of antimicrobial resistance development was also evaluated.5
Key findings of the study include5:
Based on their findings, Liu and colleagues5 recommended the following approaches when managing patients with severe COVID-19 pneumonia: (1) empiric use of antibacterial agents in cases indicative of a viral aetiology; (2) discontinuation of empiric antibiotics after 48 hours in the absence of sputum or bacterial growth upon sampling; (3) use of the length of hospital stay and patient’s clinical trajectory as critical factors when determining the need for antibiotic therapy and choice of appropriate agents (extended duration of hospitalisation may predispose patients to nosocomial pathogens); and (4) periodic review of culture tests, antibiotic use and clinical outcomes among hospitalised COVID-19 patients.5
Overall, the study emphasised the significance of understanding the associated risk factors and timing of antimicrobial resistance development to optimise antibiotic usage with the aim to prevent antimicrobial resistance development and to improve patient outcomes in the management of severe COVID-19 pneumonia.5