Intensive Care Disinfection Practices May Be Fueling Superbugs

An international study has shown for the first time a strong and direct connection between the increase in antibiotic-resistant bacteria and universal disinfection procedures for patients admitted to intensive care units. The study – published in the journal The Lancet Microbe – suggests a rethinking of the guidelines followed by healthcare facilities for the large-scale use of disinfectants.

“Our research highlights the unintended consequences of universal decolonization, in a global context where antibiotic resistance is a growing threat,” says Marco Oggioni, full professor at the Department of Pharmacy and Biotechnology of the University of Bologna, one of the authors of the study. “The responsible management of coordinated interventions for the prevention of antibiotic-resistant infections is a fundamental issue, but this should never hinder our critical reassessment of the tools we use to achieve these goals.” 

Universal decolonization is a preventive procedure applied to patients when they are admitted to intensive care: the entire body is disinfected with chlorhexidine, a disinfectant also widely used to sanitize medical devices and hospital surfaces, and a nasal treatment is applied with another disinfectant called mupirocin. The procedure was introduced in the 1990s and has proven effective in containing the spread of MRSA ( Methicillin-Resistant Staphylococcus aureus ), methicillin-resistant staphylococcus : a bacterium resistant to some antibiotics that can cause serious infections. 

For several years, the use of universal decolonization has reduced the prevalence of MRSA infection from 30-40% to less than 5% in many countries including Scotland, where this study was conducted. The scenario in Italy is different, because according to data from the Istituto Superiore di Sanita we are still at 26% of MRSA. “Currently there are different practices within healthcare facilities in the UK, with some hospitals adopting universal decolonization for all patients, while others take a more targeted approach of decolonizing only patients who have tested positive for MRSA,” explains Oggioni. “As a result, hospitals practicing universal decolonization for all patients are using much larger volumes of disinfectants such as chlorhexidine and mupirocin.” 

Looking at two Scottish healthcare facilities using these two different approaches to decolonization, the researchers then compared the levels of bacterial infection and rates of antibiotic resistance in patients admitted to intensive care over the course of 13 years.

The results show that the hospital that practiced universal decolonization for all patients had higher infections caused by the superbug MRSE ( Methicillin-Resistant Staphylococcus epidermidis), a less common infection than MRSA, but now on the rise and resistant to several types of antibiotics.

"The results we obtained show that the excessive use of disinfectants in the practice of universal decolonization may not offer advantages in terms of infection control, but instead causes the inadvertent increase in MRSE infections", confirms Professor Hijazi, coordinator of the study. "In intensive care units where the risk of MRSA infections is low, the indiscriminate use of decolonization could therefore be not only ineffective but also potentially harmful".

"This applies to regions where the prevalence of MRSA is low, such as Scotland", recalls Oggioni. "In Italy, however, the risk of MRSA infection is decreasing but still very high, which is why both targeted and universal decolonization is still necessary. Therefore, it will be necessary to decrease the prevalence of MRSA in Italy too before reassessing the risks and benefits associated with the intervention procedures".

The authors of the study therefore suggest reassessing the procedures currently in use in light of the changes that have occurred in recent years. New standardized guidelines are needed that indicate the most effective decolonization treatments, taking into account both the benefits for fighting infections and the potential contraindications in terms of antibiotic resistance.

Reference: Sharaf S, Lawes T, Roos D, et al. Universal versus targeted chlorhexidine and mupirocin decolonisation and clinical and molecular epidemiology of Staphylococcus epidermidis bloodstream infections in patients in intensive care in Scotland, UK: a controlled time-series and longitudinal genotypic study. Lancet Microbe. 2025. doi: 10.1016/j.lanmic.2025.101118

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