As of May 29, 2014, there have been 636 laboratory-confirmed cases of Middle East respiratory syndrome coronavirus (MERS-CoV), with 193 deaths, which translates into a case fatality rate of 30.3%.(1) There is currently no specific treatment for the infection other than supportive medical care. The majority of recent cases appeared to arise from human-to-human transmission and have mainly occurred within the healthcare setting.(2) Although Singapore has had no MERS-CoV cases to date, we remain at continued risk for MERS-CoV importation in view of the significant number of travellers to and from the Middle East for religious (i.e. Umrah and Hajj), recreational, medical and business purposes.
In this issue of Singapore Medical Journal, Chung et al have summarised a very interesting and relevant debate on whether surgical masks – as opposed to N95 respirators – would suffice in the prevention of MERS-CoV transmission in non-aerosol-generating circumstances in the hospital setting.(3) This debate was jointly organised in July 2013 by the Society of Infectious Disease (Singapore) and Infection Control Association (Singapore), with Chung et al updating the salient points with evidence published this year.(3) Although no clear outcome was reached during the debate, it is noteworthy that in the ten months that have elapsed since the debate, there has been no new evidence supporting the use of the more expensive N95 respirator – which, incidentally, also impairs air exchange for the wearer(4) and carries a fairly significant risk of adverse effects with prolonged use(5,6) – over the surgical mask in preventing MERS-CoV cross-infections.
Nonetheless, given the high case fatality rate of MERS-CoV and the lack of any specific treatment, it is understandable why healthcare staff and policymakers may prefer to support recommendations on the use of N95 respirators in preventing nosocomial MERS-CoV transmission, despite the increased costs and risk of adverse effects. What constitutes acceptable risks and benefits in this situation is therefore subjective and influenced by local perceptions and culture. While the use of masks or respirators is important in preventing the spread of such viruses, other infection control interventions (e.g. improving hand hygiene, and early detection and isolation of infected patients) are also important and additive in reducing the risk of MERS-CoV transmission.(7)
REFERENCES
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