Low Rates of Bacterial Co-Infections in COVID-19 Patients

SARS-CoV-2, COVID-19, coronavirus
Study authors analyzed microbiological data on COVID-19 patients to assess for bacterial co-infections associated with antimicrobial therapy.

Bacterial and fungal co-infections in patients with coronavirus disease 2019 (COVID-19) are rare and mainly prevalent in critically ill patients, according to data published in the European Journal of Clinical Microbiology & Infectious Diseases.

In this retrospective study, 140 patients with COVID-19 were admitted to a German hospital between February and April. By May, 13 patients (9%) were in general wards, 14 (10%) were in intensive care units (ICU), 18 (13%) had died, and 95 (68%) were released. Patients were separated into 2 subgroups: moderate (n=84) if they were admitted to the general ward and severe (n=56) if they were admitted to the ICU or had died.

The median age was 63.5 years and 64.3% were men. Both the median age and the number of men were higher among severe cases. Of the 135 patients for whom antibiotic data was available, 109 (80.7%) received empiric antibiotic therapy within 24 hours of admission. Only 19 patients (14.1%) never received antibiotics during hospitalization.

A total of 118 patients (84.3%) had blood culture taken, of which 10 (7.1%) were positive. Only 5 patients had true bacteremia with bloodstream infection, producing a blood culture diagnostic yield of 4.2%. Urinary antigen tests for Legionella pneumophila and Streptococcus pneumoniae were taken for 111 (79.3%) and 107 (76.4%) patients, respectively, all of which were negative. Pathogens were detected in 23 of 50 critically ill ICU patients, predominantly Enterobacterales (34.0%) and Aspergillus fumigatus (18.0%). No multidrug-resistant gram-negative pathogen or methicillin-resistant Staphylococcus aureus were detected.

Patients received either ampicillin/sulbactam with or without azithromycin for a median of 6 days (41.5%; range, 1-13) or piperacillin/tazobactam with or without azithromycin for a median of 10 days (19.3%; range, 3-26 days). While antimicrobial stewardship guidelines recommend the use of ampicillin/sulbactam, it does not advise azithromycin in combination with beta-lactam antibiotics. However, this combination was given to 43 (31.9%) patients.

Limitations include small sample size, inclusion of only admitted patients with COVID-19, and lack of respiratory samples.

“[A]ntimicrobials were being administered at a high rate, but the number of confirmed bacterial infections was low,” investigators concluded.


Rothe K, Feihl S, Schneider J, et al. Rates of bacterial co-infections and antimicrobial use in COVID-19 patients: a retrospective cohort study in light of antibiotic stewardship. Eur J Clin Microbiol Infect Dis. Published online November 2, 2020. doi:10.1007/s10096-020-04063-8.