A CDC-recommended hospital disinfectant is ineffective against Clostridioides difficile, according to a study published Nov. 21 in Microbiology.
Hypochlorites are widely used in healthcare sites as a disinfectant, according to the CDC, including sodium hypochlorite, also known as household bleach. The CDC recommends a 1:100 dilution of 5.25%-6.15% sodium hypochlorite for small spills of blood, according to the agency's guideline for healthcare disinfection and sterilization.
Researchers in the U.K. tested the disinfectant's efficacy by exposing three strains of C. diff, a hospital-acquired infection that affects about 500,000 Americans each year, to three concentrations of the solution. For 10 minutes, C. diff met 1,000, 5,000 and 10,000 parts per million sodium hypochlorite.
None of the C. diff strains showed changes to the spore coat and there was no significant reduction in spore viability. Researchers then applied the spores from the three strains to patient gowns and surgical scrubs before treating the bacteria with the disinfectant. Fewer spores were recovered, but the fabric still retained spores, indicating a tolerance to sodium hypochlorite.
In a news release, lead author Tina Joshi, PhD, said the results should spur a review of C. diff disinfection guidelines.
"It shows we need disinfectants, and guidelines, that are fit for purpose and work in line with bacterial evolution," Dr. Joshi, professor in molecular microbiology at the University of Plymouth, said. "The research should have significant impact on current disinfection protocols in the medical field globally."