COVID-19 worsens antibiotic resistance

While rare, infection with antibiotic-resistant gram-negative bacteria (AR-GNB) following a positive COVID-19 diagnosis is more severe and often results in worse outcomes, according to a study presented at the recent Virtual ID Week 2022.

The study included 3,904 patients with AR-GNB infections, of whom only 4 percent (n=163) had a preceding positive COVID-19 test. Specifically, 85 of these infections were extended spectrum beta-lactamase-producing Enterobacterales, 70 were carbapenem-resistant Enterobacterales, and eight were carbapenem-resistant Acinetobacter baumannii. Time from the COVID-19 test to AR-GNB culture took a median of 20 days. [ID Week 2022, abstract 86]

Patients who had COVID-19 before their AR-GNB infections were more likely to be 65 years or older (62 percent vs 52 percent; p=0.0139) and have had prior healthcare exposures (63 percent vs 49 percent; p=0.0003). Indwelling devices were also significantly more common in these patients (51 percent vs 28 percent; p<0.0001).

In terms of clinical measures, patients with prior COVID-19 were also more likely to have bacteraemia (24 percent vs 11 percent; p<0.0001) and pneumonia (6 percent vs 1 percent; p<0.0001) and to be hospitalized at the time AR-GNB was cultured (67 percent vs 36 percent; p<0.0001).

“This underscores the need for continued infection prevention and control practices and monitoring of these infections during the COVID-19 pandemic,” the researchers said.

Multidrug-resistant coinfection

In a separate study also presented at the Virtual ID Week 2022, researchers investigated the risk factors that could predispose COVID-19 patients to coinfection with multidrug-resistant organisms, drawing data from Veterans Affairs hospitals.

The retrospective cohort analysis included 33,383 patients with confirmed COVID-19 tests and ran from 1 March 2020 through 31 May 2022. Coinfection was the primary outcome of interest. Cases were classified as hospital-onset when they occurred >2 calendar days after admission and as community-onset if the infection arose within 2 days of admission.

Statistical analyses were carried out in two stages, first focusing on individual-level factors before assessing facility-level correlates of coinfection risk.

Mixed effects logistic regression analysis revealed that patients on medication for ventilator induction were nearly three times more likely to have multidrug-resistant hospital-onset coinfections (odds ratio [OR], 2.9, 95 percent confidence interval [CI], 2.2–3.9).  [ID Week 2022, abstract 787]

Similarly, norepinephrine treatment (OR, 1.6, 95 percent CI, 1.2–2.2) and receiving antimicrobial therapies for gram-positive bacteria (OR, 4.5, 95 percent CI, 3.6–5.6) were associated with higher odds of hospital-onset coinfections. Homeless participants also saw an excess risk of this outcome (OR, 1.5, 95 percent CI, 1.1–2.0).

Meanwhile, community-onset coinfection was significantly predicted by being admitted into a facility with high Clostridioides difficile infection rates (OR, 1.14, 95 percent CI, 1.11–1.18).

According to the researchers, aside from basic sociodemographic factors, predictors of hospital- and community-onset coinfection with multidrug-resistant microbes are distinct in patients with COVID-19. “Further work is needed to better understand the risk factors for coinfection,” they said.