Hospital Environmental Improvements May Lower Rate of C Difficile Infections

Improving environmental conditions and private hospital rooms may decrease the rate of hospital-onset clostridium difficile infections (CDI), according to a study published online in the American Journal of Infection Control. For the study, the authors evaluated trends in quarterly CDI incidences using a segmented regression analysis model prior to and after patients were relocated to a new hospital, with the model including the timing of the hospital relocation.

While researchers at Okayama Saiseikai General Hospital (OSGH) in Okayama City, Japan, were evaluating associated risk factors, they noted a shift in the incidence of hospital-onset CDI after patients were relocated to a newly built hospital with 50% private rooms. They added that hospital-onset CDI frequently occurs because of both patient and environmental risk factors.

The researchers also evaluated the link between incidence of CDI and environmental factors at the ward-level using a linear regression analyses model. The study was conducted between January 1, 2013, and June 30, 2019, which was 3 years before and 3.5 years following the hospital relocation.

Patients in the study were originally treated at OSGH before being moved to a nearby new hospital building on January 1, 2016. OSGH is an acute care hospital with 553 beds and 15 departments. Approximately 50% of patients are admitted due to gastrointestinal, hepatic, biliary, pancreatic, and respiratory diseases.

The researchers noted environmental conditions and cleaning of patient rooms during the length of the study. The hospital was observed to follow a specific protocol for CDI prevention, such as recommendations for patient handwashing and for individuals who came into contact with infected patients, as well as protective gear, disinfectant, and quarantines.

The investigators found 322 hospital-onset CDI cases among 524,475 patient-days in OSGH over the 3-year period compared with 62 infections among 531,697 patient days in the new hospital over the 3.5-year period. Incidence of hospital-onset CDI fell from 6.14 to 1.17 per 10,000 patient-days in OSGH and new hospitals, respectively. Further, the community-onset CDI incidence rate dropped from 1.71 to 0.46 per 1000 admissions.

Prior to relocation, the researchers did not observe a downward trend (Coef. 0.005, 95% CI, -0.053 to 0.063, P = 0.85); however, following relocation there was a significant downward trend (Coef. -0.111, 95% CI, -0.185 to -0.038, P = 0.006) as the number of cases dropped by 11% every 3 months.

The researchers used a Poisson regression analysis to calculate an IRR of 0.19 (95% CI, 0.15 to 0.25, P ≤ 0.001) around the time of hospital relocation. This represents an 81% decrease in hospital-onset CDI cases at the new hospital, which was not transient, but continued for at least 3.5 years after the relocation, according to the study.

A positive correlation in hospital-onset incidence of CDI was found with community-onset CDI incidence, but this inversely correlated with the private room ration (adjusted R2 = 0.83). Further, approximately half of the patients with community-onset CDI were hospitalized within 28 days preceding the onset.

Using the Poisson regression analysis, the incidence rate ratio was 0.27 (95% CI, 0.16 to 0.44, P < 0.001) around the time of hospital relocation and there were no significant downward trends before relocation (Coef. -0.006, 95% CI, -0.086 to 0.073, P = 0.87). The researchers also observed that incidence of community-onset CDI was the strongest predictor of hospital-onset CDI incidence, as each community case increased per 1000 admissions associated with a 2.1 rise in hospital-onset infections per 10,000 patient-days (P <0.001, R2 = 0.73).

“Environmental improvements after relocation may have reduced the reservoir of C. difficile, resulting in a decrease in the number of asymptomatic carriers and [community-onset] CDI patients,” the study authors wrote. “Relocation to a new hospital significantly reduced [hospital-onset] CDI incidence, concomitantly decreasing the incidence of [community-onset] CDI, potentially due to environmental improvements.”

Reference

Shiode J., et all. Correlation between hospital-onset and community-onset Clostridioides difficile infection incidence: ward-level analysis following hospital relocation. American Journal of Infection Control. Online. https://www.sciencedirect.com/science/article/pii/S0196655322000748. Published February 12, 2022. Accessed February 21, 2022.