Antimicrobials Frequently Prescribed in Hospitalized COVID-19 Patients

The prevalence of microbiologically-confirmed bacterial infections are rare among patients admitted to the hospital with COVID-19, according to new findings from 2020 UK data that indicate an overuse of antimicrobial agents in the treatment of the pandemic virus.

Observed outcomes from the ongoing International Severe Acute Respiratory and Emerging Infections Consortium (ISARIC) WHO Clinical Characterisation Protocol UK (CCP-UK) showed that more than one-third of patients with COVID-19 were prescribed antimicrobial therapy prior to hospitalization—and most were prescribed a regimen while hospitalized.

However, less than 13% of COVID-19 patients with available data presented with bacterial co-infections.

Investigators, led by Clark D. Russell, MBChB, of the University of Edinburgh, the investigators conducted the prospective cohort assessment of inpatient data from 260 hospitals in England, Scotland and Wales. Eligible data included patients with confirmed or clinician-defined high likelihood of SARS-CoV-2 infection; Russell and colleagues excluded patients with recorded negative SARS-CoV-2 test results, and those without a recorded outcome at 28 days post-admission.

The team collected demographic, clinical, laboratory, therapeutic, and outcome data via a prespecified case report form.

Data were collected from 48,902 patients admitted to a hospital between February 6 and June 8, 2020. Median patient age was 74 years old (IQR, 59 – 84), and 42.6% were female.

Recorded microbiological investigations were observed in 8649 (17.7%) patients, with clinically significant COVID-19 related respiratory or bloodstream culture results recorded for 1107 patients.

Secondary infections, defined as occurring ≥2 days after hospital admission, were recorded in 762 (70.6%) of the 1080 observed infections. Staphylococcus aureus and Haemophilus influenzae were the most common respiratory co-infection pathogens; Enterobacteriaceae and S aureus were the most common secondary respiratory infections.

Investigators additionally observed Escherichia coli and S aureus as the most common bloodstream infections.

Among the 36,145 COVID-19 patients with available data, 13,390 (37.0%) had received antimicrobials for their illness prior to hospitalization. Another 39,258 (85.2%) of 46,061 COVID-19 patients with antimicrobial data had received ≥1 antimicrobial during their hospital admission—the greatest prevalence observed among critical care patients.

“Most studies to date have been retrospective with small sample sizes, and few have systematically reported the spectrum of bacteria, timing of infection onset, or described the frequency and nature of antimicrobials used to treat them,” investigators wrote. “There is an urgent need to characterise the causes of bacterial infections in patients admitted to hospital with COVID-19 to determine optimal empirical antimicrobial management strategies and identify targets for antimicrobial stewardship interventions.”

In a statement accompanying the research, Russell stressed the findings contribute to the “much-needed depth” of understanding around antimicrobial use during the pandemic—as well as contributing to concepts of optimizing their use.

“Prioritising and incorporating existing antimicrobial stewardship principles into care plans could help to prevent a rise of drug-resistant infections becoming a longer-term sequela of the pandemic,” Russell said. “Our study looked at only the first pandemic wave in the UK, so it is important that future studies assess antimicrobial usage later in the pandemic, both in the UK and other parts of the world.”

The team concluded with calls for prospective, standardized research of comprehensive microbiological sampling prior to antimicrobial therapy, in order to better characterize co-infections and secondary infections in patients with COVID-19.

“Tractable targets for antimicrobial stewardship interventions exist and should be prioritized,” they wrote.