MRSA in decline but Salmonella and E. coli re-emerging as hospital acquired infections

Posted: 28/05/2012

Expert and Health Protection Agency (HPA) data reports that there has been a drop in infection rates of the superbugs MRSA and C. difficile in NHS hospitals in England. However, other infections like E. coli appear to have taken their place.

According to a survey by the HPA, which covered 103 hospital trusts and 52,443 eligible patients, including 1,665 from the private sector, the total prevalence of healthcare-associated infections (HCAIs) decreased from 8.2% in 2006 to 6.4% in 2011. The average age of patients was 69 and 4,372 children under the age of 16 were among those surveyed. The results showed that 3,360 patients were diagnosed with an active HCAI, with 135 having more than one. Among the most common HCAIs were respiratory, urinary tract and surgical site infections. Infection prevalence was highest among infants and the elderly. It was also highest in intensive care units, where 23.4% of patients were affected.

Much of the decrease was due to lower rates of MRSA and C. difficile - infections that the Government has repeatedly targeted with policies. Since 2006, there had been an 18-fold reduction in rates of infection by the superbug MRSA from 1.3% to 0.1%. Clostridium difficile infection rates had reduced five-fold from 2% to 0.4%.

At the same time, rates of other infections, like E. coli, appear to be rising. In a third of cases, bacteria such as Salmonella and E. coli, collectively known as coliforms, were the cause. 12.4% of these coliforms were resistant to the antibiotics normally used to treat these infections, known as cephalosporins. Experts are concerned that coliforms infections are becoming more prevalent and harder to treat.

Over the last five years, there has been a 35% increase in reports of E. coli blood infections. Report author Dr Susan Hopkins said: "When you get rid of one bacteria, another one will sneak into its place. We are seeing a slow but steady rise in E. coli. It is clear that we need to find ways to control and prevent transmission of these bacteria, and this is an important priority."

Most HCAIs developed during the patients' stays in the hospital. But a fifth of HCAIs were present on admission to hospital. Unlike MRSA, which can be screened for, everyone possesses coliform bacteria. In most people they exist harmlessly in the gut. But in some people - typically the elderly, very sick or very young - they can cause serious and even life-threatening infections. Dr Hopkins said: "Everyone has it, so we can't screen and get rid of it. We need to look at better hygiene to prevent infections."

Mark Wilcox, consultant and member of the HPA, said that transmission of enterobacteriaceae, including E.coli, often occurs as a result of gastrointestinal surgery and use of drains, catheters, and lines. He suggests the use of barriers around the surgery entry site and procedures for ensuring hygienic use of devices to reduce this transmission.

The NHS should be pleased at the improvement in incidence of infection by the ‘superbugs’ but there is clearly much to be done to address this new problem.

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