MRSA decolonisation in a district general hospital

A pilot service evaluation study to assess decolonisation of MRSA, and whether other measures to control MRSA, such as isolation and contact precautions, were implemented appropriately, is presented

A pilot service evaluation study to assess decolonisation of MRSA, and whether other measures to control MRSA, such as isolation and contact precautions, were implemented appropriately, is presented

Hashim Elshibly
David Farren MB BCh BAO MRCP FRCPath
Mamoon Aldeyab PhD
Laboratory
Geraldine Conlon-Bingham PhD
Michael Scott PhD
Pharmacy Department, Antrim Area Hospital, Northern Health and Social Care Trust, Northern Ireland, UK
  Email: [email protected]  

Control of methicillin-resistant Staphylococcus aureus (MRSA) infection is a major challenge in health care facilities. Decolonisation may reduce the risk of MRSA infection in individual carriers and prevent re-infection and/or transmission to other patients. In our Trust, targeted MRSA screening and decolonisation of high-risk patients was adopted in the general wards as universal untargeted decolonisation is unsustainable in the long term, mainly due to issues of increased resistance to the agents used in decolonisation^1,2 and lack of cost effectiveness. Some settings, such as intensive care units,^3,4 were automatically considered high-risk and so were subject to routine screening on admission and thereafter weekly. Within Northern Ireland there has been an increased incidence of MRSA bacteraemia across all sectors compared with previous years, with 75 cases reported across Northern Ireland as a whole.

Aim
This is a pilot service evaluation study to assess whether decolonisation of MRSA was performed in the hospital or after discharge or not as indicated by the Trust’s MRSA policy and whether other measures to control MRSA, such as isolation and contact precautions,
were implemented appropriately.

In addition, it was also assessed as to whether or not failure to decolonise resulted in further infection for the patient. The study was carried out in the Antrim Area Hospital in Northern Ireland, UK, a 426-bed district general teaching hospital serving a population of approximately 420,000. The hospital provides all acute, general medical and surgical services.

Method
Patient demographics were collected from the Trust’s MRSA register for September 2015. Forty-four patient notes were examined and reviewed to determine whether or not decolonisation was carried out. Patients who were not decolonised were followed up to date, that is, for one year after isolation of MRSA through both the notes and the Trust’s laboratory record system to see if they developed MRSA infection, whether in the hospital or in the community.

Results
Forty-four patients’ charts were examined: 18 (40.9%) females; 26 (59.1%) males; 35 (79.5%) patients aged above 65 years; and 9 patients (20.5%) were <65 years old. Of these, 35 (79.5%) patients were admitted to medical wards, 7 (15.9%) to surgical wards, 1 (2.3%) to Accident and Emergency and 1 (2.3%) to the obstetrics ward (Table 1).

Re-infection with MRSA occurred in only one (2.3%) patient. Isolation in a side room was undertaken in 11 (25%) patients while contact precautions were implemented in 41 patients (93.2%). Site-specific screening was requested for two (4.5%) patients. The majority of MRSA isolates were from initial screening of 36 patients (81.8%).

Discussion
A number of studies have discussed and confirmed the success rate (32%–65%)⁶ of MRSA decolonisation. However, few have discussed the consequences of failure or non-decolonisation. This pilot service study showed that just less than one third (14; 31.8%) of the patients studied were decolonised for MRSA. Follow up for one year after isolation of the MRSA from these carriers and who were not decolonised showed evidence of re-infection in one patient (2.3%). This follow up was carried out through reviewing both the patients’ records and the hospital’s laboratory system.

According to the hospital policy, site-specific screening should be done before commencing decolonisation as this will determine the extent of MRSA carriage and allow a clinical decision to be made regarding decolonisation. Site-specific screening was requested in only two patients (4.5%) and one of them was not decolonised. This probably reflects a lack of awareness of the importance of decolonisation and hence the need for site-specific screening.

Isolation in side rooms of carriers or patients infected with MRSA is one of the most important measures to control MRSA spread in the hospitals.⁷ However, in UK hospitals, high bed occupancy and scarcity of side rooms has made this measure difficult to apply each time. Instead a risk assessment exercise and prioritisation is made before a side room is occupied by an MRSA carrier. This has led to the cohorting of MRSA-colonised patients in bays, or nursing individual patients in a bay with strict enforcement of contact precautions.

This hospital is no exception to this approach. Out of the 44 patients, one patient (2.3%) was isolated in a side room. Adoption of contact precautions was well documented in the nursing notes 41 (93.2%). A recent internal audit for MRSA control practices in real life showed an overall adherence to the control precautions varied between 30% and 100% in different wards (unpublished data, personal communication).

The small number of patients recruited in this pilot study makes it difficult to draw firm conclusions but has allowed an initial indication as to how well the various control measures were applied during this time period.

Conclusions
The pilot study has been useful as a precursor for a larger study that may answer further questions such as examining whether or not failure or non-decolonisation resulted in more infection to the patient or/and resulted in cross infections in the hospital or in associated care homes. It is now intended to carry out a larger study.

Key points

• While a number of studies confirm the success rate (32–65%) of decolonisation, few have discussed the consequences of failure or non-decolonisation.
• Targetting screening and decolonisation of high risk patients was adopted in general wards as universal untargetted decolonisation in unsustainable in the long term.
• Site-specific screening that trust policy states should be done before commencing decolonisation, was requested in only two patients.
• A recent internal audit of MRSA control practices showed an overall adherence to control precautions varied between 30–100% in different wards (unpublished data/personal communication)
• Within Northern Ireland there has been an increased incidence of MRSA bacteraemia across all sectors compared with previous years.

References

1. Batra R et al. Efficacy and limitation of a chlorhexidine-based decolonization strategy in preventing transmission of meticillin-resistant Staphylococcus aureus in an intensive care unit. Clin Infect Dis 2010;50:210–17.
2. Cookson BD. The emergence of mupirocin resistance: a challenge to infection control and antibiotic prescribing practice. J Antimicrob Chemother1998;41:11–18.
3. Huang SS et al. Targeted versus universal decolonisation to prevent ICU infection. N Engl J Med 2013;368:2255–65.
4. Robotham JV et al. Screening, isolation and decolonisation strategies in the control of methicillin resistant Staphylococcus aureus in intensive care units: cost effectiveness evaluation. BMJ 2011;343:d5694.
5. Gilpin DF et al. Efficacy of a standard meticillin-resistant Staphylococcus aureus decolonisation protocol in routine clinical practice. J Hosp Infect 2010;75:93–8.
6. Kohler P et al. MRSA decolonization: success rate, risk factors for failure and optimal duration of follow-up. Infection 2013;41:33–40.
7. Duerden B et al. Control of meticillin-resistant Staphylococcus aureus blood stream infections in England. Open Forum Infect Dis 2015;2(2):ofv035.