Investigation links cockroaches to outbreak of resistant bacteria in ICU
Click Here to Manage Email Alerts
Key takeaways:
- Cockroaches can carry pathogens linked to nosocomial infections.
- Health care workers should report the presence of insects in patient rooms.
Cockroaches contributed to an outbreak of multidrug-resistant Enterobacter cloacae in an ICU over the course of 20 months, according to a study that linked outbreak strains to strains found in the insects.
Hospitals outside the United States have recognized that cockroaches can potentially spread pathogens, according to the authors of the study.
However, “Insects have not generally been considered as a source for environmental contamination in hospitals because there are very few studies linking insects to outbreaks,” Jennifer A. Hanrahan, DO, an infectious diseases internist at MetroHealth Medical Center in Cleveland, told Healio. “There are studies showing that insects carry various organisms, but there are very limited data connecting the organisms cultured from insects to infections in humans.”
Cockroaches are relatively common pests in all buildings, including hospitals, and although all hospitals have pest control programs, cockroaches can be “extremely difficult to control” in large buildings, Hanrahan said.
According to the CDC, cockroaches are known to feed on fixed sputum smears in laboratories, found anywhere in facilities where water or moisture is present, and often frequent loading docks and other areas with access to the outdoors.
Although the presence of insects itself is unlikely to spread health care-associated infections in developed countries, the CDC noted that cockroaches carry pathogenic microorganisms on their surfaces and in their gut, which may be spread if there are lapses in some standard infection control practices.
Hanrahan and colleagues analyzed medical records, culture data and environmental infection control measures in an ICU for 20 months after a possible outbreak was reported by infection prevention (IP) staff, who noted two people in adjacent rooms with multidrug-resistant Enterobacter cloacae (MRE) and theorized cross-transmission between them.
During the outbreak, cultures were collected for 128 ICU patients. Among them, 25 (19.5%) were either infected or colonized with MRE, according to the study.
Environmental investigations revealed MRE contamination on a variety of patient room surfaces. The hospital reinforced cleaning procedures in the ICU and kept some rooms empty for periods of time, but surfaces continued to test positive for MRE, the researchers reported.
During follow-up conversations, a nurse reported that she had seen “an occasional cockroach in patient rooms,” although she said they were rare. Researchers caught a cockroach, placed it on sheep blood agar and permitted it to walk around for several hours. The plate later tested positive for MRE, among other resistant pathogens.
After the hospital reinforced pest control measures, no patients were found to have MRE for 3 months. Another cockroach was found in the ICU months later, and a new patient was colonized by MRE within a week, although no further cases were identified, according to the study.
Noting that the outbreak was rectified after talking to frontline hospital staff about how to solve the problem, the researchers wrote that insects — including cockroaches — should be considered potential vectors for infections.
“Health care workers likely underestimate the potential for insects to contribute to health care-acquired infections,” Hanrahan said. “Health care facilities should have robust pest control programs, and health care workers should report the presence of insects.”
References:
- Hanrahan J, et al. Antimicrob Steward Healthc Epidemiol. 2024;doi:10.1017/ash.2024.425.
- CDC. Infection control: Environmental infection control guidelines. https://www.cdc.gov/infection-control/hcp/environmental-control/index.html. Published Dec. 14, 2023. Accessed Oct. 15, 2024.
Collapse
Read more about
Click Here to Manage Email Alerts