No Association Found Between COVID-19 Pandemic and Incidence of Health Care-Associated C. Difficile Infections

The COVID-19 pandemic did not lead to any statistically significant differences in health care-associated Clostridioides difficile (HA-CDI) infections when compared to non-COVID-19 periods, according to the results of a study published in Infection Prevention in Practice.

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Traditionally, C. difficile is one of the most prevalent health care-associated infections (HAIs). Predisposing factors for infection include exposure to C. difficile spores and previous exposure to broad-spectrum antimicrobials.

Once the COVID-19 pandemic began, hospitals were restructured, with a heavy reliance on infection prevention and control (IPC), including hand hygiene and personal protective equipment. The increased focus on IPC may have positively impacted HAIs and reduced the prevalence of C. difficile; however, the shift in resources to the COVID-19 response and away from surveillance of HAIs could have resulted in an increase in infections.

The investigators aimed to conduct a retrospective study at a tertiary hospital in Ireland to examine the impact of the COVID-19 pandemic on the incidence of HA-CDI from January 2019 to December 2022. The primary outcome of the study was to assess the impact of the COVID-19 pandemic on HA-CDI rates, with additional outcomes that looked at gross incidence rates, antimicrobial consumption, and testing practices during the study period.

Although the overall trend in HA-CDI shows a very marginal decrease over the study period, comparisons between COVID-19 and non-COVID-19 periods found no statistically significant difference in HA-CDI (P = 0.34). Additionally, there was no significant difference in the consumption of all antimicrobials (P = 0.091), fluoroquinolones only (P = 0.067), third generation cephalosporins only (P = 0.449), or carbapenems only (P = 0.944).

The overall number of bed-days was noted to be statistically less during the COVID-19 period (P = 0.034), as well as the absolute number of C. difficile tests performed during that period (P = 0.029). However, when expressed as a rate to reflect hospital activity, the difference in tests performed was not statistically significant (P = 0.696).

Previously conducted studies in Spain, Dublin, Rome, and Mexico observed a lower than anticipated incidence of HA-CDI in comparison to historical data sets, whereas those conducted in New York and Singapore have reported no significant impact. The results of the current study support the latter conclusion, the investigators wrote.

The researchers discussed the presence of antimicrobial exposure and its association with the development of CDI. A study in Scotland indicated that limiting hospital use of high-risk antimicrobials was associated with a substantial CDI decline.

Furthermore, studies in the United States have shown that facilities with significant reductions in hospital antimicrobial use experienced reductions of HA-CDI. This trend was reflected in the analysis of the investigators, although they note that it was minor and not statistically significant.

Another possible explanation for the study results centers around pandemic testing practices. During the pandemic, many clinical services in hospitals and the community were either suspended or severely curtailed, which led to a reduction in patient consultations. At the same time, COVID-19 also produced gastrointestinal symptoms, which may have led to a reduced number of requests for C. difficile testing.

Lastly, the change in organizational structure and resource utilization throughout the pandemic may have impacted the implementation of appropriate IPC policy regarding isolation or accommodation of patients with transmissible infections. It may also suggest a delay in time to isolation of individuals with C. difficile symptoms, and a greater probability of environmental contamination and exposure.

Some limitations were acknowledged by the researchers. Their findings were observational, retrospective, and from a very defined cohort, which limits the generalizability of results and the inability to infer casual relationships. The study also lacks patient-level data, and individual risk factors for developing HA-CDI may have differed between the COVID-19 and non-COVID-19 cohort.

Reference

Ali S and McDermott S. Impact of the COVID-19 pandemic on the incidence of healthcare-associated Clostridioides difficile infection in a tertiary healthcare facility in the Republic of Ireland. Infect Prev Pract. 2023;5(3):100300. doi:10.1016/j.infpip.2023.100300