The results of a study published today in the American Journal of Infection Control (AJIC) provide new information that could help long-term care (LTC) facilities assess the cleanliness of high-touch surfaces, and thus improve infection prevention and control measures designed to prevent serious diarrheal illnesses and deaths among their residents. The study evaluated the usefulness of specific hygiene monitoring tools to assess levels of microbial contamination on high-touch surfaces in 11 LTC facilities in South Carolina.
Our study is one of only four conducted to date to assess environmental hygiene in long-term care facilities. Increasingly, hospitals are performing routine cleanliness audits of high-touch surfaces, helping to reduce resident morbidity and mortality. Our results suggest that similar audit programs would benefit long-term care facilities when included as part of their infection prevention programs.”
Jennifer Cannon, Ph.D., CDC Foundation field worker working with the Centers for Disease Control and Prevention (CDC), and lead author of the paper
Diarrheal diseases caused by noroviruses and It’s hard (CDI) are among the most common nosocomial infections in long-term care facilities; in the United States, approximately 60% of norovirus outbreaks and more than 50% of all healthcare-associated CDIs occur in long-term care facilities. Both pathogens can be transmitted through environmental surfaces contaminated with feces. Although environmental monitoring using surface hygiene indicators is a valuable tool to help prevent the spread of infection, there are no standard technologies or methodologies, and many monitoring tools are too expensive to be used routinely.
For their study, Dr. Cannon and his colleagues used three tools to assess the cleanliness of a minimum of 30 surfaces in each of 11 LTC facilities in South Carolina: adenosine triphosphate (ATP), a bioluminescent chemical reaction that indicates the presence of organic matter; norovirus; and crAssphage, a recently discovered DNA bacteriophage that indicates past or present fecal contamination. Their study was the first to use crAssphage as an indicator of fecal contamination in the setting of LTC.
Ninety percent of high-touch surfaces tested by researchers (n=337) either tested positive for crAssphage or had levels of organic material that caused ATP cleanliness scores to fail.
- crAsphage was detected on 311 (92.3%) surfaces, often at high levels (median concentration of 3.5 log genomic copies).
- Almost all 324 (98%) surfaces had elevated levels of ATP, resulting in a “fail” score using the cutoff values suggested by the ATP kit manufacturer.
- All 337 surfaces tested negative for norovirus. The researchers suggest this finding is consistent with previous studies suggesting that noroviruses are rarely detected in the absence of a current or recent outbreak.
Aggregating data from the 11 facilities, Dr. Cannon and his colleagues combined the ATP and crAssphage tools to identify the types of surfaces and locations most likely to be contaminated with organic or fecal matter:
- Handrails and equipment controls were four times more likely to have high levels of crAsphage than other surfaces and locations (odds ratio [OR] 4.1, CI 2.0-8.5, p
- Patient bed rails and tables and chairs in patient lounges had elevated levels of ATP and crAsshage.
- Locations in LTC facilities most likely to have elevated levels of crAssphage were patient beds (OR 3.9, CI 1.4-12.3, p
- Surfaces touched by patients and visitors were twice as likely to have elevated levels of ATP as those touched primarily by nursing and housekeeping staff or by patients alone.
“This study provides valuable new information that could help long-term care facilities monitor their cleaning practices and refine their infection prevention plans to better protect patients from serious diarrheal illness,” said Linda Dickey. , RN, MPH, CIC, FAPIC and President of APIC 2022.
Association of Infection Control Professionals
Canon, JL, et al. (2022) Hygienic monitoring in long-term care facilities using ATP, crAssphage, and human norovirus to direct cleaning of environmental surfaces. American Journal of Infection Control. doi.org/10.1016/j.ajic.2021.11.014.