Infection control measures for the prevention of MERS coronavirus transmission in healthcare settings
Middle East respiratory syndrome coronavirus (MERS CoV) had caused multiple large health care associated infections and outbreaks.[1 7] The first outbreak was identified retrospectively in a hospital in Zarqa, Jordan, in April 2012. [4] In that outbreak, 2 of 13 people (including 10 healthcare workers (HCWs) tested positive for MERS CoV based on polymerase chain reaction.[4] Furthermore, a serologic study showed an attack rate of 10% among exposed HCWs and 5% among family contacts.[5] The 2013 AlHasa outbreak in the Kingdom of Saudi Arabia occurred in four hospitals and 21 of 23 (91% of cases were healthcare acquired.[1] The rate of acquisition of MERS CoV was less than 1% among 200 exposed HCWs.[1] The third outbreak took place in Jeddah, Saudi Arabia, in 2014 and occurred in 14 hospitals with a total of 128 cases. [2,3] Of 112 non HCWs, 109 (97.3% contracted infection within health care settings.[3] Most recently on May 2015, an index case, 68 year old male from South Korea visited many countries in the Middle East (Bahrain/Saudi Arabia/ UAE/Qatar) and developed symptoms on 11 May 2015 and was subsequently seen in multiple hospitals in South Korea.[6] In about 2 weeks, he sparked an outbreak involving 5 health care facilities and 63 cases.[7] There were 34 cases in hospital B, 18 cases in hospital D, 5 cases in hospital E, and 3 cases in hospital F.[7] According to the WHO as of 19 June 2015, the outbreak in the Republic of Korea involved 72 health care facilities which have treated patients and 6 health care facilities had nosocomial transmission.[8] The total number of cases as of 26 June 2015 was 182 cases with 31 deaths.[9,10] The index case in this outbreak eventually was responsible for a total of 185 infections during a 4 week period, mainly through inhospital transmission.[11] Sequence analysis of isolates from four patients representing at least four generations of transmission showed no evidence of changes in the virus.[11] HCWs in the various MERS outbreaks constituted 18% in South Korea outbreak[10] and 31% in the outbreaks in the Kingdom of Saudi Arabia.[1,12 14] In a recent review, the estimated percent of total symptomatic and asymptomatic HCWs who tested positive was 2% 67%[14] There seems to be propensity of the MERS CoV to be effectively transmitted within healthcare facilities. The various factors facilitating such transmission had not been clearly elucidated except for that in all health care facilities associated outbreaks; major breakdown in infection control procedures had occurred.[14] In Al Hasa outbreak, one patient infected 20 other people.[1] Further genomic sequence analysis showed that the MERS outbreak was due to more than one introduction of the virus into the outbreak.[15] In that outbreak, one MERS patient was linked epidemiologically to seven secondary cases.[1] In an outbreak in Riyadh, Saudi Arabia, one patient contributed to 10 secondary cases.[16] In the recent outbreak in South Korea, of the initial 119 cases, 27 secondary cases in a single hospital were linked to the primary case and two secondary cases causing a second wave of the outbreak.[10] A total of 97 tertiary cases emerged.[10] The exact role of superspreader or a superspreading event in contributing to the different outbreaks is not well described. Implementation of effective infection control measures in health care setting is vital for the control of the transmission of microorganisms. The recommendations from the US and European Centers for Disease Control and Prevention call for the use of airborne infection isolation (AII) precautions for patients with suspected EXPERT REVIEW OF ANTI INFECTIVE THERAPY, 2016 VOL. 14, NO. 3, 281 283 http:/dx.doi.org/10.1586/14787210.2016.1135053
Expert review of anti infective therapy