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NIHR Signal Treating asymptomatic MRSA on discharge from hospital reduces risk of later infection

Published on 29 April 2019

doi: 10.3310/signal-000766

Use of medicated creams, mouthwash and body wash for six months after discharge from hospital led to a 30% lower risk of MRSA infection, compared with basic hygiene education. This study was carried out in the USA using 2,121 adults who had tested positive for MRSA in hospital, but who had no symptoms.

Meticillin-resistant Staphylococcus aureus (MRSA) bacteria have developed resistance to widely-used antibiotics. MRSA is easily transferable within healthcare settings, and people may become colonised in hospital or the community. People can carry MRSA without any symptoms, and usually, with time, their normal skin bacteria will eradicate the MRSA strain. Unfortunately, MRSA may sometimes cause them potentially serious infections.

Rates of MRSA are higher in the USA, and therapy regimens may differ, but this study found that the intervention was effective and this should be relevant to practice here.

  •   Health management, Infections, Medicines, Primary care, Acute and general medicine
Treating asymptomatic MRSA on discharge from hospital reduces risk of later infection

Why was this study needed?

The number of cases of MRSA and the number of deaths following MRSA infection has fallen in the last 10 years in the UK.

Healthcare-associated infections cost the NHS around £1 billion per year, with about £56 million of this thought to be spent after patients are discharged from hospital.

People can have MRSA without having symptoms or signs of infection: this is called MRSA colonisation. Being an MRSA carrier can increase the risk of MRSA infection, and of passing on the bacteria to others.

Decolonisation uses medicated creams and body wash solutions to remove the bacteria. It has been shown to be effective at reducing infection while patients are in hospital. This study aimed to assess whether it is an effective treatment after hospital discharge, when rates of infection can be high.

What did this study do?

This randomised controlled trial included 2,121 adults admitted to hospital who tested positive for MRSA. It compared hygiene education on discharge to education plus decolonisation. The education intervention gave patients information about MRSA and how it is spread, with advice about personal hygiene and household cleaning. The decolonisation group received the same information, plus an intervention which involved using chlorhexidine mouthwash twice a day, mupirocin nasal cream twice a day, and daily bathing or showering with chlorhexidine. This regime was carried out for five days twice a month, for six months. Participants were followed up for 12 months after discharge.

The study relied on self-report of patients’ adherence to the intervention. Patients were aware of their treatment group, although clinicians assessing the outcomes didn’t know which group patients were in.

What did it find?

  • The risk of MRSA infection in the decolonisation group was 30% lower than in the education group (hazard ratio 0.70, 95% confidence interval [CI] 0.52 to 0.96). MRSA infection occurred in 98/1,063 (9.2%) of the education group compared with 67/1,058 (6.3%) of the decolonisation group.
  • The lower risk of MRSA infection in the decolonisation group led to a 29% lower risk of hospitalisation due to MRSA (hazard ratio 0.71, 95% CI 0.51 to 0.99).
  • There was a high rate of early exit from the trial, 35% of the education group and 37% of the decolonisation group.
  • Better adherence to the decolonisation regimen was associated with lower rates of infection. Analyses using data relating to how participants were actually treated (rather than how they were randomised) showed that those in the decolonisation group who adhered fully had 44% fewer MRSA infections than those in the education group (hazard ratio 0.56, 95% CI 0.36 to 0.86).
  • Side effects of the decolonisation intervention were reported by 44 participants (4.2%). The side effects were mild local irritations, caused by the products. Of those reporting side effects, 39% chose to continue using the products.

What does current guidance say on this issue?

In 2015, the Department of Health published a code of practice on the prevention and control of infections, under the Health and Social Care Act 2008. This recommends that every organisation should have a policy that makes provision for suppression regimens for MRSA-colonised patients when appropriate.

The code also advises that measures are in place to transfer infected or colonised patients within an organisation or to other care facilities. It doesn’t make recommendations specifically about discharge from hospital.

What are the implications?

While relatively few carriers of MRSA end up with an infection, those that do often end up back in hospital. This study suggests that patients who test positive for MRSA in hospital should be treated after discharge, even if they show no symptoms, in order to reduce the risk of later MRSA infection.

Decolonisation treatment is most effective when patients follow the regimen exactly. However, the intensive programme of daily products, and the length of the treatment, may make it difficult for patients to stick to when in their own homes, without medical supervision.

Citation and Funding

Huang SS, Singh R, McKinnell R et al. Decolonization to reduce postdischarge infection risk among MRSA carriers. N Engl J Med. 2019;380(7):638-50.

This project was funded by the Agency for Healthcare Research and Quality (AHRQ) Healthcare-Associated Infections Program and the University of California Irvine Institute for Clinical and Translational Science.

Bibliography

DH. The Health and Social Care Act 2008: Code of practice on the prevention and control of infections and related guidance. London: Department of Health; 2015.

NHS website. MRSA. London: Department of Health and Social Care; 2017.

NICE. Healthcare-associated infections: prevention and control in primary and community care. CG139. London: National Institute for Health and Care Excellence; 2012 (updated 2017).

Expert commentary

This is a high-quality study from a well-established group. The use of MRSA suppression for a prolonged period post discharge was effective in reducing MRSA infections in a large cohort.

If delivered effectively there should be a good cost benefit, and surprisingly resistance was not a problem in the outpatient setting.

Professor Peter Wilson, Consultant Microbiologist, Clinical Microbiology and Virology, UCLH NHS Foundation Trust

The commentator declares no conflicting interests

Expert commentary

Huang and colleagues demonstrate a 30% reduction in MRSA infection over 12 months in carriers of the organism receiving twice monthly chlorhexidine and mupirocin decolonisation therapy for the first six months following discharge. Of note, prevalent strains of MRSA in the USA are different from those in the UK and typically are more likely to cause disease in healthy hosts. In addition, participants were offered payment for their involvement which may have had an impact on their adherence to therapy.

Current UK practice is to attempt decolonisation and to consider repeating if unsuccessful but not to have a proscribed regimen of periodic therapy. This study suggests that considering such serial courses may be worthwhile even in patients unlikely to eradicate the organism (e.g. those with chronic wounds or indwelling devices).

Participants all received the educational intervention, the breadth of which is currently variable in the UK and this may be a further area of interest.

Dr Dave Partridge, Consultant Microbiologist and Research Lead for the Directorate of Laboratory Medicine, Sheffield Teaching Hospitals Foundation Trust

The commentator declares no conflicting interests