Antimicrobial Stewardship (AMS)

Resources to help you ensure the safe and effective use of antimicrobials in NSHA patients.

Antibiotic Use in Adult COVID-19

Most patients with COVID-19 have mild respiratory disease and recover with supportive care alone. Investigational antivirals and immunomodulatory treatments may be considered as part of approved clinical trials and will be assessed by an Infectious Diseases physician prior to initiation in Nova Scotia Health (NSH).

Antibiotics for bacterial pneumonia are often unnecessary in patients with COVID-19. The rates of bacterial pneumonia co-infections and secondary infections are low.

  • One review suggested the rate of bacterial co-infection in nine studies of patients with COVID-19 may be 8%
    • Co-infection on presentation may be as low as 3.5%1
    • Secondary bacterial infection during illness or hospitalization is likely higher at 15.5%1
  • CRP is a non-specific inflammatory marker and is often elevated in COVID-19
  • COVID-19 infection itself often causes persistent fever and bilateral infiltrates

Last revised November 2020

Empiric Bacterial Pneumonia Treatment in Patients With COVID-192

COVID-19 Severity Antibiotic Treatment


  • No supplemental oxygen and typically managed as outpatients
No antibiotic therapy


  • Clinical signs of pneumonia, usually managed as inpatients and may require low-flow supplemental oxygen

No antibiotic therapy unless strong clinical suspicion for bacterial infection such as 

  • acute fever after defervescence / initial improvement with new consolidation on chest imaging

A gradually worsening respiratory failure in the first week is more likely to be from progression of COVID-19 than from a new superimposed secondary bacterial pneumonia.

  • Managed in ICU with high oxygen and/or circulatory support
Antibiotic treatment for community-acquired pneumonia (CAP), hospital-acquired pneumonia (HAP), or ventilator-associated pneumonia (VAP) as indicated (link to Spectrum)
  • If bacterial co-infection is suspected, obtain blood cultures +/- sputum cultures [latter if ICU admission requiring intubation, concern of MRSA or resistant Gram-negatives (e.g. Pseudomonas), hospitalization and receipt of parenteral antibiotics in the last 90 days, or copious sputum production]
  • Consider testing for Legionella urinary antigen in severe CAP (requiring ICU admission) or if patient is associated with a local Legionella outbreak
  • Antibiotics should be reassessed daily for de-escalation based on clinical status and microbiology results
  • Minimize duration:
    • CAP 5 days
    • HAP, VAP 7 days

Other sources of infection (e.g. UTI, cellulitis, sepsis, etc) should be assessed as usual in COVID-19 patients and treated if indicated. There is no evidence that prolonged or more aggressive antimicrobial courses are warranted in COVID-19 patients.

Antibiotics are not benign and may result in adverse events including: 

  • C. difficile infection 
  • Antimicrobial resistance
  • Nephrotoxicity
  • Arrhythmias

Last revised November 2020

1. Langford BJ, So M, Raybardhan S, Leung V, Westwood D, MacFadden DR, Soucy J-PR, Daneman N, Bacterial co-infection and secondary infection in patients with COVID-19:a living rapid review and meta-analysis Clinical Microbiology and Infection,

2. Ontario Clinical Practice Guidelines for Antimicrobial and Immunomodulatory Therapy. Available from:

3. Clinical Management of COVID-19: interim guidance: World Health Organization; 2020 Available from:

4. Clinical Management of Patients with Moderate to Severe COVID-19 - Interim Guidance (April 2, 2020) Available from:

5. Rawson TM, Moore LSP, Zhu N, Ranganathan N, Skolimowska K, Gilchrist M, et al. Bacterial and fungal co-infection in individuals with coronavirus: A rapid review to support COVID-19 antimicrobial prescribing. Clin Infect Dis. 2020.

6. Wang L, He W, Yu X, Hu D, Bao M, Liu H, et al. Coronavirus disease 2019 in elderly patients: Characteristics and prognostic factors based on 4-week follow-up. J Infect. 2020;80(6):639-45.

7. Wu CP, Adhi F, Highland K. Recognition and management of respiratory coinfection and secondary bacterial pneumonia in patients with COVID-19 [published online ahead of print, 2020 May 11]. Cleve Clin J Med. 2020;ccc015.

Last reviewed November 2020