Chlorine disinfectant no more effective than water at killing hospital superbug: Study

New Delhi: One of the primary chlorine disinfectants currently being used to clean hospital scrubs and surfaces does not kill the most common cause of antibiotic-associated illness in health care settings globally, according to a study.

Researchers at the University of Plymouth in the UK found that spores of Clostridioides difficile, commonly known as C. diff, are completely unaffected despite being treated with high concentrations of bleach used in many hospitals.

They found that the chlorine chemicals are no more effective at damaging the spores when used as a surface disinfectant than using water with no additives.

The study, published in the journal Microbiology, shows that susceptible people working and being treated in clinical settings might be unknowingly placed at risk of contracting the superbug.

With incidence of disinfectant overuse only serving to fuel rises in antimicrobial resistance (AMR) worldwide, the researchers call for urgent research to find alternative strategies to disinfect C. diff spores in order to break the chain of transmission in clinical environments.

“With incidence of anti-microbial resistance on the rise, the threat posed by superbugs to human health is increasing,” said Tina Joshi, Associate Professor at the University of Plymouth, who carried out the study with Humaira Ahmed, a fourth-year Medicine student at the university.

“But far from demonstrating that our clinical environments are clean and safe for staff and patients, this study highlights the ability of C. diff spores to tolerate disinfection at in-use and recommended active chlorine concentrations,” Joshi said.

C. diff is a microbe that causes diarrhea, colitis and other bowel complications and is known to infect millions of people all over the world each year.

The study examined spore response of three different strains of C. diff to three clinical in-use concentrations of sodium hypochlorite.

The spores were then spiked onto surgical scrubs and patient gowns, examined using scanning electron microscopes to establish if there were any morphological changes to the outer spore coat.

“Understanding how these spores and disinfectants interact is integral to practical management of C. diff infection and reducing the burden of infection in health care settings,” Joshi said.

“However, there are still unanswered questions regarding the extent of biocide tolerance within C. diff and whether it is affected by antibiotic co-tolerance. With AMR increasing globally, the need to find those answers–both for C. diff and other superbugs–has never been more pressing,” she added.