Health-care workers (HCWs) should be more aggressively screened in combination with eradication treatments and other infection control measures to help bring down rates of MRSA infection in hospitals and other health-care facilities with endemic MRSA. These are the conclusions of authors of a Review in the May issue of The Lancet Infectious Diseases.
In the Review, entitled Health-care workers: source, vector, or victim of MRSA, Stephan Harbarth, Infection Control Programme, University Hospitals of Geneva, Switzerland, and Werner Albrich, University of the Witwatersand, Johannesburg, South Africa, re-analysed data from 169 studies comprising 33318 screened HCWs from 37 mostly high-income countries, to determine the role of personnel in MRSA transmission.
They found that 4.6% of these workers carried MRSA, and of these, 5.1% had clinical MRSA infections. The authors say: "Poor infection control practices were implicated in both acquisition and transmission of MRSA by personnel, but even good adherence to infection control -- including masks and hand hygiene -- did not entirely prevent transmission of MRSA from heavily colonised staff to patients."
The authors discuss how HCWs with nasal or throat MRSA carriage can become "cloud HCWs" -- referring to a release of substantial clouds of MRSA into the air by personnel during their own upper respiratory tract infections. Burn patients or patients with large open wounds can be at particularly high risk for airborne MRSA infection. They also discuss how community-associated MRSA (CA-MRSA) and healthcare-acquired MRSA (HA-MRSA) have spread to close contacts of healthcare workers. Not only does this entail risk for family members, but can also lead to further spread of MRSA.
While a recent review of MRSA outbreaks suggested HCW screening should be focussed on those workers with symptomatic infection, the authors say: "Screening of infected health-care workers only will likely miss a large number of asymptomatic personnel capable of transmitting MRSA to patients since staphylococcal carriage is mainly dependent on whether the person is a nasal carrier…Our search revealed 18 studies with proven and 26 studies with likely transmission to patients from HCWs who were not clinically infected with MRSA."
The authors propose HCW screening should take place irrespective of the presence of risk factors or puss-producing (purulent) infections as part of pre-employment examination, or (especially in the case of large outbreaks) even periodically and unannounced before a work shift to avoid detecting only transient carriers. Further, in order to increase detection of MRSA, both nose and throat swabs should be taken with separate swabs since eradication therapy differs depending on the location of the MRSA. Whilst acknowledging that implementing screening is not feasible in many health-care settings because of its cost, the authors point out that in regions of low MRSA prevalence such as Scandinavia, the Netherlands, and Western Australia, close health-care worker surveillance is practised routinely. They say: "We recommend screening of health-care workers during outbreak investigations and during early stages of an institutional epidemic when MRSA prevalence is still low or when a new MRSA strain is propagating rapidly. In settings with endemic MRSA or limited resources, priority should be given to staff in high-risk units such intensive care units, burn units, or surgical wards."
The advantages of this screening are that it would contribute to termination of MRSA outbreaks, long-term cost savings, reduction of individual risk of clinical MRSA infection in HCWs, and increased patient and public confidence. Disadvantages would be immediate costs, increased workload, disruption of patient care, and tensions between HCWs and the infection control team. The authors say: "Screening and eradication of health-care workers’ MRSA status should always be part of a comprehensive infection control policy including staff education and emphasising high compliance with hand hygiene and contact precautions. Care must be taken to avoid feelings of guilt or stigmatisation among colonised HCWs and to avoid disrupting the relationship between HCWs and the infection control team." They add: "MRSA carriage or infection in a HCW should be considered an occupational hazard and injury according to local legislation, thereby avoiding negative career consequences."
They conclude: "HCWs are likely to be important in the transmission of MRSA, most frequently acting as vectors and not as the main sources of MRSA transmission. Thus, good hand hygiene practices remain essential to control the spread of MRSA…Although no single approach to dealing with MRSA in HCWs will work universally, aggressive screening and eradication policies seem justified in outbreak investigations or when MRSA has not reached endemic levels."
Stephan Harbarth, Infection Control Programme, University Hospitals of Geneva, Switzerland T) +41 223723357 E) Stephan.harbarth@hcuge.ch
Agnes Reffet, Communications, University Hospitals of Geneva, Switzerland T) +41 22 372 60 07 E) agnes.reffet@hcuge.ch
http://www.eurekalert.org/jrnls/lance/pdfs/TLIDMRSAstafffinal.pdf
Journal
The Lancet Infectious Diseases