Mortality risk and antibiotic use for COVID-19 in hospitalized patients over 80

Patients over 80 years of age are more prone to develop severe symptoms and die from COVID-19. Antibiotics were massively prescribed in the first days of the pandemic without evidence of super infection. Antibiotics may increase the risk of mortality in cases of viral pneumonia. With age and antibiotic use, the microbiota becomes altered and less protective effect against lethal viral pneumonia. Thus we assessed whether it is safe to prescribe antibiotics for COVID-19 pneumonia to patients over 80 years of age.

We conducted a retrospective monocentric study in a 1240-bed university hospital. Our inclusion criteria were patients aged ≥ 80 years, hospitalized in a COVID-19 unit, with either a positive SARS-CoV-2 RT-PCR from a nasopharyngeal swab or a CT scan within 72 h after or prior to hospitalization in the unit suggestive of infection.

We included 101 patients who received antibiotics and 48 who did not. The demographics in the two groups were similar. Overall mortality was higher for the group that received antibiotics than for the other group (36.6% vs 14.6%,). According to univariate COX analysis, the risk of mortality was higher (HR = 1.98 [0.926; 4.23]) but non-significantly for the antibiotic group. In multivariate analysis, independent risk factors of mortality were an increased leukocyte count and decreased oxygen saturation (HR = 1.097 [1.022; 1.178] and HR = 0.927 [0.891; 0.964], respectively).

This study raises questions about the interest of antibiotic therapy, its efficacy, and its effect on COVID-19 and encourages further research.