When it comes to reducing Methicillin-Resistant Staphylococcus aureus (MRSA) infections, more aggressive screening of health-care workers (HCWs) is necessary in combination with other infection control measures in hospitals and other health-care facilities with endemic infection. This was reported in a Review published in the May issue of The Lancet Infectious Diseases.
In order to study the rold of personnel in MRSA transmission, Stephan Harbarth, Infection Control Programme, University Hospitals of Geneva, Switzerland, and Werner Albrich, University of the Witwatersand, Johannesburg, South Africa, reexamined data from 169 studies making up 33,318 total HCWs from 37 countries, most of which were high-income countries.
MRSA was carried by 4.6% of these HCWs. Of these workers, 5.1% had clinical MRSA infections. According to the authors, this was true even when proper infection control practices were being followed. “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.”
HCWs with nasal or or throat MRSA can become “cloud HCWs,” releasing clouds of MRSA into the air via upper respiratory tract infections. Airborn MRSA infections can especially affect burn patients or patients with large, open wounds, according to the authors. Additionally, community-associated MRSA and healthcare-acquired MRSA have spread not just to workers but to their close contacts. This can lead to further spread of the bacterium, not to mention risk of infections in the contacts themselves.
The conclusions of the authors of this Review are in contrast with another group, which suggested that HCW screening should be focusedon workers who show symptomatic infection. The authors of this Review 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.”
According to the authors, HCW screening should take place regardless of risk factors or pus-producing infections noted in the pre-employment examination. In fact, they suggest that, in the case of large outbreaks, screening should occur periodically and unannounced before work shifts, in order to avoid missing other carriers. Additionally, increased detection could be achieved using both nose and throat swabs, because the eradication therapy methods differ depending on the location of the MRSA.
The authors acknowledge that implementing screening is not feasible because of cost constraints in many health-care settings, but also point out that the regions showing the lowest levels of MRSA practice the most routine close surveillance of their HCWs. These include Scandinavia, the Netherlands, and Western Australia. “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.”
Screening could have many advantages — it could contribute to the termination of MRSA outbreaks, reduction in cost, reduction of the individual risk of clinical MRSA infection in HCWs, and increased confidence on the part of the patient and the public. The disadvantages include higher immediate costs, increased workload, disruption of patient care, and various tensions between HCWs and the infection control team.
The authors note that the increased screening should be implemented with care. “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 continue: “MRSA carriage or infection in a HCW should be considered an occupational hazard and injury according to local legislation, thereby avoiding negative career consequences.”
The authors conclude, emphasizing the importance of HCWs in the MRSA transmission process. “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.”
Health-care workers: source, vector, or victim of MRSA?
Werner C Albrich, Stephan Harbarth
The Lancet, Vol 8, May 2008
Written by Anna Sophia McKenney