Editorial Commentary: Still Learning From the Earliest Known MERS Outbreak, Zarqa, Jordan, April 2012

In this issue of Clinical Infectious Diseases, Mohammad Al-Abdallat and colleagues from the Jordan Ministry of Health (MOH) and the US Centers for Disease Control and Prevention (CDC) provide the most comprehensive report to date on the earliest known outbreak of the Middle East respiratory syndrome (MERS) coronavirus (CoV) [1]. This retrospectively diagnosed intensive care unit/critical care unit (ICU/CCU)–associated outbreak occurred in April 2012 in a large public hospital in Zarqa, Jordan, located 25 km northeast of the Jordanian capital of Amman [2]. The authors, using 3 antibody assays developed by the CDC, are the first to provide serologic data on this outbreak. These assays advance the ability to conduct wider population-based serosurveys for MERS as well as to assist in the diagnosis of individual patients. Importantly, these serologic assays should be compared collaboratively with other MERS serologic tests published in 2012 and 2013, particularly by European investigators in the Netherlands and Germany [3–5]. More generally, this earliest known MERS outbreak in the Middle East affords an opportunity to create international consensus guidelines for laboratory testing when explicitly searching for a novel infectious disease agent. The persistent investigative response by the Jordan MOH to this April 2012 outbreak is fascinating and instructive and is an exemplary model of outbreak response. The MOH undertook at least 3 major epidemiologic investigations. The first in April 2012 stopped the outbreak of the unknown and likely contagious hospital-associated pneumonia that involved 13 persons, most of whom were healthcare personnel. Importantly, patient samples from at least 2 of the fatal cases were obtained and stored. The second major investigation was with the World Health Organization (WHO) in November–December 2012 after the laboratory-confirmed diagnosis of MERS had been made retrospectively on the stored specimens from the 2 fatal cases [2, 6, 7]. The third was in collaboration with the CDC in May 2013. This study added 7 survivors who, 13 months after the outbreak, had at least 2 serologically positive tests for anti–MERS-CoV antibodies [1]. A more detailed summary of the timeline for this outbreak in Zarqa is instructive in illustrating the efforts made to identify the cause of the outbreak. The initial outbreak communication response by the Jordan MOH occurred on 19 April 2012 when they closed the ICU at Zarqa Public Hospital and notified the press that 1 healthcare worker had died due to this outbreak of “pneumonia.” On 20 April the Jordan Times published the first of a series of articles on the outbreak [8]. Notably, the European Centre for Disease Control and Prevention (ECDC) published an epidemiological summary and assessment in its 29 April 2012–5 May 2012 Communicable Disease Threats Report. ECDC noted that 1 nurse had died and that at least 7 nurses and 1 doctor had a febrile lower respiratory illness. Citing the Jordan MOH, it was reported that the cause was likely to be viral; however, no laboratory tests were available. ECDC stated that due to the severity and “unusualness” of the illness in healthcare personnel, they contacted WHO and the CDC and that both organizations also “are following this event” [9].Meanwhile, the outbreak was stopped, in part, by creating a case definition that focused on unexplained pneumonia and transferring suspected patients to 2 hospitals in Amman where strict infection control measures were undertaken (unlike in the ICU/CCU at Zarqa Hospital). The onset of illness for the last patient was on 26 April [2]. In a subsequent WHO update (30 November 2012) on the outbreak, it was noted that in April Jordan MOH made Received 28 July 2014; accepted 30 July 2014. Correspondence: Daniel R. Lucey, MD, MPH, Suite 321 SW Medical Dental Building, Department of Microbiology and Immunology, Georgetown University Medical Center, 3900 Reservoir Road NW, Washington, DC 20057 (drl23@ georgetown.edu). Clinical Infectious Diseases © The Author 2014. Published by Oxford University Press on behalf of the Infectious Diseases Society of America. All rights reserved. For Permissions, please e-mail: journals. permissions@oup.com. DOI: 10.1093/cid/ciu638