Deadly Superbugs Infect Thousands of People at US Hospitals. Now The Bleach Used to Kill Them Doesn’t Work

Using bleach to disinfect hospital surfaces and surgical gowns is no more effective than plain water at killing Costridioides difficile, also known as C. diff, a common yet deadly hospital superbug, according to a new study. 

In a study published Tuesday in the journal Microbiology, researchers from the University of Plymouth in England found that the spores of C. diff, a bacteria that infects about half a million Americans each year, remained intact on hospital surfaces, fabrics and scrubs despite being scrubbed clean using hospital-recommended levels of chlorine bleach (sodium hypochlorite). 

The researchers used three different bleach solutions against three separate C. diff strains to test the bleach's effectiveness. However, the researchers found that the spores survived and remained unaffected by the bleach exposure.

C. diff is a deadly bacteria commonly found in hospital settings. It is a serious infection that causes repetitive diarrhea, colon inflammation, fever, stomach pain and nausea and can be incredibly painful and uncomfortable for patients. 

While it can affect anyone, the bacteria is more likely to affect those who have been taking antibiotics or just finished a course. Symptoms typically develop within a few days after you begin taking antibiotics.

Older adults over 65, people with a recent hospital or nursing home stay, and people with a weakened immune system or previous C. diff infections are more likely to contract the superbug, according to the Centers for Disease Control and Prevention. 

In fact, research shows that one in six people who develop a C. diff infection will get it again in two to eight weeks. And one in 11 people over 65 who pick up the bug in a hospital setting die within one month. Yearly, the contagious bacteria is responsible for around 29,000 deaths in the United States and 8,500 in Europe. 

According to the researchers, bleach is not only ineffective at destroying C. diff but, on the contrary, overusing ineffective biocides such as bleach and other special cleaning agents to destroy this superbug is fueling the rise of antimicrobial resistance (AMR) globally.

When the hospital-grade cleaning agents are unable to destroy the superbug successfully, it creates an environment for the bacteria to thrive and multiply and become resistant to existing forms of treatments, such as antibiotics and other medications used to treat infectious diseases. 

“With the incidence of antimicrobial resistance on the rise, the threat posed by superbugs to human health is increasing. 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,” lead author Tina Joshi, Ph.D., an associate professor in Molecular Microbiology at the University of Plymouth, said in a statement. 

Further, Dr. Joshi notes that the study findings indicate the need for effective alternative cleaning solutions that could help reduce the growing burden of hospital infections for both medical staff and patients as bacteria continue to evolve and become resistant.

“With AMR increasing globally, the need to find those answers – both for C. diff and other superbugs – has never been more pressing,” Dr. Joshi said.