Analysis of over 1,300 German adults hospitalised with moderate COVID-19 finds treatment with antibiotics was associated with five times greater likelihood of COVID-19 deterioration compared to patients not given antibiotics.
To explore this further, Dr Friedrichs and colleagues analysed data on 1,317 hospitalised adults (median age 59 years; 38% women) with confirmed SARS-CoV-2 infection between March 2020 and May 2023 from the German National Pandemic Cohort Network (NAPKON), which includes patients from various hospitals across Germany who were hospitalised with a positive SARS-CoV-2 PCR test.
Using the WHO Clinical Progression Scale [1], they identified 1,149 patients who were classified as having moderate disease (WHO score 4-5), of whom 467 (41%) were treated with antibiotics commonly used for respiratory infections such as ß-Lactam-antibiotics, macrolides, or moxifloxacin during their hospital stay.
A further 168 patients were classed as having severe disease (WHO score 6-9), of whom 118 (70%) also received antibiotic treatment. The data on these patients are still being analysed.
Microbiological investigations of patients with moderate disease identified only 11 patients with a superinfection with a bacterium that can also cause pneumonia—eight patients treated with antibiotics and three who did not receive antibiotics (see table 1 in the poster). The authors note that the low number of patients with documented respiratory bacterial superinfection might be due to missing microbiological diagnostics or missing documentation of results. Other bacterial infections suggestive for antibiotic therapy were not included in the analysis.
Being male, older, more frail, with greater disease severity, a higher burden of comorbidities and no prior COVID-19 vaccination was associated with a significantly greater likelihood of being treated with antibiotics.
Researchers then analysed the influence of antibiotic therapy on patients’ clinical status after 14 days measured using the WHO Clinical Progression Scale, which reflects a patient’s trajectory and resource use over the course of clinical illness [1]. The score indicates disease severity incorporating hospital admission, oxygen requirement, ventilator support, admission to intensive care unit and organ replacement therapy. The score was calculated for each patient at the initial clinician’s consultation, and again 14 days later to see whether the score had improved, remained stable, or worsened.
After controlling for COVID-19 risk factors including age, sex, and underlying medical conditions, the analyses found that clinical improvement in patients with moderate disease was significantly better for younger, female, and vaccinated patients.
Importantly, patients given antibiotics had five times greater risk of clinical deterioration after 14 days compared to those not treated with antibiotics. Similarly, being aged 65 or older trebled the likelihood of COVID-19 deterioration compared to those aged 18-50 years.
As Dr Friedrichs explains, “This increased risk is possibly due to unknown additional factors that result in worse outcomes and are associated with antibiotic treatment. One potential factor that was only occasionally documented is a bacterial superinfection, as well as other bacterial infections. Importantly, however, clinical deterioration can also develop from the side effects of unnecessarily prescribed antibiotics.”
