Diagnosing Bacterial Co-infection in COVID-19 Patients

Clinical Indicators of Bacterial Co-infection

Critically ill COVID-19 patients, especially those requiring ICU admission or mechanical ventilation, have a higher risk of bacterial co-infection and may require antibiotic therapy 1, 2
Laboratory findings suggestive of bacterial co-infection include elevated white blood cell count 2, 3, elevated C-reactive protein levels 3, 4, and procalcitonin level >0.5 ng/mL 2, 3
Serum biomarkers alone should not determine when to start antibiotics, especially in non-critically ill patients 2, 3

Syndromic diagnostic testing (multiplex PCR) should be performed using specimens from endotracheal tube samples or bronchoalveolar lavage (BAL) 1, 3
Conventional cultures should always be performed in parallel with PCR testing 2, 3
Nasopharyngeal swabs are not recommended for guiding antimicrobial treatment during early COVID-19 3, 5

Restrict antibiotic use in mild-to-moderately ill COVID-19 patients, especially those with low initial PCT levels (<0.25 ng/mL) 3, 6
For non-critically ill patients with suspected bacterial co-infection, use empirical antibiotics covering both typical and atypical pathogens of community-acquired pneumonia 4, 7
For critically ill patients with suspected bacterial co-infection, consider empirical anti-MRSA antibiotics 2, 7
Serial PCT measurements should be performed in all hospitalized patients, especially critically ill or mechanically ventilated patients 3, 6
Early de-escalation or discontinuation of antibiotics is recommended in patients with low PCT levels (<0.25 ng/mL) 3, 6