A new study has revealed that chlorine disinfectant, commonly used in hospitals to prevent infections, is no more effective than water at killing a dangerous superbug.
The study, conducted by researchers from the University of Leicester and published in the journal Infection Control and Hospital Epidemiology, tested the efficacy of chlorine disinfectant against Clostridioides difficile (C. diff), a bacterium that causes severe diarrhoea, colitis and other bowel complications.
Chlorine disinfectant widely used but not effective
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Chlorine disinfectant is widely used in hospitals, COVID-19 quarantine facilities, households, institutes, and public areas to combat the spread of the novel coronavirus and other pathogens, as it is effective against viruses on various surfaces.
However, the study found that chlorine disinfectant was not able to reduce the number of viable C. diff spores, which are the dormant and resistant form of the bacterium that can survive for long periods on surfaces and cause infections.
The researchers exposed C. diff spores to different concentrations of chlorine disinfectant for various contact times, ranging from 10 seconds to 60 minutes.
They then measured the number of viable spores that remained after the treatment.
According to the study's findings, chlorine disinfectant did not significantly reduce the number of viable spores, even at high concentrations and long contact times. In fact, water alone was equally effective as chlorine disinfectant at killing C. diff spores.
Implications for infection prevention and control
The study has important implications for infection prevention and control practices in healthcare settings, as C. diff is one of the most common causes of healthcare-associated infections worldwide.
According to the Centers for Disease Control and Prevention (CDC), C. diff infected nearly half a million people in the United States in 2017 and was associated with 29,000 deaths.
C. diff infections are also costly, as they prolong hospital stays and increase the need for antibiotics and isolation measures.
The study suggests that chlorine disinfectant may not be sufficient to prevent the transmission of C. diff spores in healthcare environments, and that alternative disinfectants or methods may be needed.
The researchers recommend that further studies should be conducted to evaluate the effectiveness of other disinfectants, such as hydrogen peroxide, peracetic acid, or UV light, against the spores.
They also suggested that environmental cleaning should be combined with other strategies, such as hand hygiene, contact precautions, and antibiotic stewardship, to reduce the risk of infections.
The study has some limitations that should be considered when interpreting the results.
First, the study was conducted in a laboratory setting, and may not reflect the real-world conditions of environmental cleaning in hospitals. For example, the study did not account for the presence of organic matter, such as blood or faeces, that may interfere with the disinfection process.
Second, the study only tested one strain of C. diff, and different strains may have different levels of resistance to chlorine disinfectant.
Third, the study only measured the viability of C. diff spores, and not their ability to germinate and cause infections.
The researchers acknowledge these limitations and call for more research to validate their findings in clinical settings and with different strains of C. diff.
They also proposed to investigate the mechanisms of C. diff spore resistance to chlorine disinfectant, and to explore the potential of combining chlorine disinfectant with other agents, such as enzymes or surfactants, to enhance its sporicidal activity.
