Report of the ARHAI Working Group on Occupational Health in Veterinary Practice: MRSA screening and the role of Occupational Health

Background This multi-disciplinary working group of the Department of Health’s Advisory Committee on Antimicrobial Resistance and Healthcare Associated Infection (ARHAI) was convened in late 2009 to explore and provide initial guidance on the occupational health issues for staff working in veterinary practice relating to animals infected or colonised with meticillin-resistant Staphylococcus aureus (MRSA). Although such exposures are currently infrequent in England, MRSA is considered in this report because it has a high public profile and there are fewer effective antibiotics to treat MRSA infections compared to those caused by meticillin sensitive S. aureus infections. However, many of the issues raised for MRSA apply equally to other organisms and veterinary practices. The group emphasised the general need to apply good standards of infection prevention and control and recognised that some veterinary practices had excellent infection control documents, which could be made available to others as examples of best practice.

2. Context of Occupational Health of Veterinary Workers A number of groups are already considering various aspects of MRSA and/or Occupational Health guidance and guidelines for veterinary healthcare workers. The British Small Animal Veterinary Association (BSAVA) has already produced guidance for the prevention and control of MRSA in companion animals (1, 2). The British Veterinary Association (BVA) has convened two groups; the BVA Member Services Group was considering occupational health issues, and the BVA Policy Group was producing a document on MRSA in all species.

3. MRSA in veterinary practice Although currently uncommon in animals in the UK, MRSA can be encountered in veterinary practice in a variety of ways (2). Well-described are the MRSA occasionally found colonising or infecting companion animals, predominantly cats and dogs. These are usually, hospital acquired strains from close contacts e.g. in the family and are carried by these animals on their fur, anterior nares and perineum. However, they can cause infections post-operatively to the animals or cross infect 1

other animals within veterinary establishments. Therapy animals can also become the reservoir or source of MRSA colonisation/infections to humans in healthcare facilities and guidance is available relating to prevention and control of MRSA in these companion animals (1). Livestock Associated MRSA (LA MRSA) are well described (usually sequence type ST 398 amongst pigs and other animals (e.g. dogs, calves, horses) elsewhere in Northern Europe and other countries. They are very different from hospital and human community associated MRSA, and have not yet been encountered in the UK, other than a very few sporadic isolated cases, for which there were no apparent contacts with livestock animals. These strains are still a cause for concern should they emerge in the UK, as those in occupational contact with these animals e.g. pig farmers, could be at an increased risk of MRSA infection when admitted for surgical procedures. However, any colonisation is likely to be detected by mandatory MRSA screening. A recent study in the South of the Netherlands has shown no increased risk of MRSA carriage in human hospital staff in close contact with livestock outside their hospitals (3). However, the situation in England needs to be reviewed regularly; and several new studies are already underway. Other MRSA can also affect horses in the United Kingdom, although the extent of this is unknown. Studies elsewhere, however, have shown that these are different from human and ST 398 MRSA strains, and do not cause human infections, although colonisation of veterinary workers is well-described (2).

4. Patterns of veterinary staff MRSA carriage Carriage rates of MRSA in veterinary surgeons and related staff are high when such staff are sampled whilst on duty (4). These findings most likely reflect transient carriage (1). More interestingly, several studies have shown that higher than expected carriage rates are also seen (even for human MRSA strains) when veterinary surgeons are sampled attending Conferences away from animal contact (2). One possible explanation is that there is continued contact with contaminated fomites. Another is that animal MRSA may behave differently from human strains. These explanations are not mutually exclusive and require further investigations.

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5. Occupational Health Guidance for Veterinary Healthcare Workers Veterinary practitioners should consider and review MRSA infection rates in their own patients and criteria as to when investigation of increased number of cases is warranted. Multiple MRSA infections within a practice may indicate that MRSA has become an endemic problem and prospective surveillance may be necessary. Any resident animals (e.g. the practice cat) should also be screened. It is important to realise that routine screening of staff and the environment is not necessary in most circumstances. Screening, as in healthcare associated human outbreaks, is, never a substitute for rigorous infection prevention and control measures, particularly hand hygiene, isolation and appropriate decontamination procedures. 5.1 Screening of veterinary staff for MRSA It is important not to just focus on screening staff, but to audit and review procedures to decontaminate the environment, including all equipment. Routine screening of staff is not necessary in most circumstances, but when undertaken it is important to differentiate transient MRSA carriage from colonisation and persistent carriage. Transient carriage is more common, and accounts for the majority of MRSA cross infection. It is controlled most effectively by hand decontamination and other hygienic measures (1, 4). Screening of staff, when indicated, should not be performed during or within 12 hours (and ideally 24h) of a period of duty in contact with MRSA positive animals, as it is very likely to detect transient or short-term MRSA contamination rather than genuine colonisation (4). Staff should be reminded (not just for MRSA related issues) that they should self- examine regularly for hand and other skin infections, problems with eczema and dermatitis and report these through locally agreed Occupational Health arrangements. Staff screening should be considered in discussion with veterinary Occupational Health/Infection Control staff if the epidemiology suggests staff to animal transmissions of MRSA not contained by infection prevention and control measures. The Occupational Health services, with the consent of the staff member, should liaise and communicate with his/her GP when decolonisation treatment is given, or if treatment of any skin condition is required .We propose that the use of an Occupational health service will usually be the most effective way to address staff-related issues. One source of advice and local (charged for) support can be found at www.NHSplus.com. .

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5.2 Veterinary workers admitted to hospital for treatment

Veterinary workers treating MRSA affected pets when admitted to hospital will now be amongst those screened as part of the mandatory universal screening of patients admitted for elective and emergency surgery. Such veterinary workers should remind NHS doctors that they have been in contact with MRSA affected animals. Ideally they should not be screened within ~12h (and ideally 24h) of contact with such animals as they may be labelled incorrectly as MRSA carriers.

6. Conclusions Currently LA MRSA and companion animal MRSA is not affecting significant numbers of animals in England, but this needs to be kept under review. Occupational Health physicians may recommend staff screening when clusters of animals with MRSA infections and associated ongoing transmission occurs. The working group confirmed that some veterinary workers exposed to MRSA affected animals were not currently able to access occupational health advice. We propose that such advice, where not available locally, should be sought from www.NHSplus.com. Staff must have had at least 12h and preferably, 24h off duty before being screened for MRSA. Two BVA groups are reviewing related issues and will consider this proposal in their current deliberations. Further detailed and updated BSAVA guidance on MRSA prevention and control is available (1) and includes the www.NHSplus.com link .

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APPENDIX 1: CONTRIBUTORS TO THE REPORT

ARHAI WORKING GROUP ON OCCUPATIONAL HEALTH

Professor Barry Cookson Chairman ARHAI Member ARHAI/DARC MRSA Group Member Dr Anil Adisesh Health and Safety Laboratory and Association of NHS Occupational Physicians. Faculty of Occupational Medicine. Mr Mike Jessop British Small Animals Veterinary Association

Dr Nicky Paull British Veterinary Association

Dr Susan Dawson ARHAI Member ARHAI/DARC MRSA Group Member Mr John Fitzgerald ARHAI Observer for DEFRA ARHAI/DARC MRSA Group Member

Dr Brian Crook Health and Safety Laboratory

Ms Nicola Ackerman Senior Veterinary Hospital Medical Nurse,

Ms Gail Beckett Senior Health Protection Nurse, Health Protection Agency

Dr Sally Millership Consultant in Communicable Disease Control, Health Protection Agency

Dr Douglas Fleming Royal College of General Practitioners

Ms Isabel Boyer ARHAI Lay member

Ms Sally Wellsteed ARHAI DH Sponsor

Dr Amy Glasswell / Dr Marika ARHAI Secretariat Collin/ Dr Yasmin Drabu

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APPENDIX 2: GLOSSARY OF TERMS

ARHAI Advisory Committee on Antimicrobial Resistance and Healthcare Associated Infections (ARHAI).

BSAVA British Small Animal Veterinary Association

BVA British Veterinary Association

DARC Department for Environment, Food and Rural Affairs (Defra) Antimicrobial Resistance Coordination Group

DEFRA Department for Environment, Food and Rural Affairs

DH Department of Health

HPA Health Protection Agency

LA MRSA Livestock Associated MRSA

MRSA Meticillin Resistant Staphylococcus aureus

VMD Veterinary Medicines Directorate - an executive agency of DEFRA

REFERENCES

1) BSAVA Council Policy Statement No. 32 (Guidance on Methicillin Resistant Staphylococcus Aureus) 2004. http://www.bsava.com/Advice/PolicyStatements/MRSA/tabid/166/Default.aspx [last accessed 23/08/11]

2) Nuttal, T, Jessop M, Cookson B, Ridgway G. Guidance on Methicillin Resistant Staphylococcus aureus. Now updated BSAVA practice guidelines – reducing the risk from MRSA and MRSP 2011. Available at: http://www.bsava.com/Advice/MRSA/tabid/171/Default.aspx

3) Wulf MW, Tiemersma E, Kluytmans J, Bogaers D et al. MRSA carriage in healthcare personnel in contact with farm animals. J Hosp Infect 2008;70:186-190

4) Cookson BD, Peters B, Webster M, Phillips I, Rahman M, Noble W. Staff carriage of epidemic methicillin-resistant Staphylococcus aureus. J Clin Micro 1989;27:1471-1476.

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