MERS-CoV Underscores Importance of Infection Control, Prevention, and Communication
SAN FRANCISCO, CA—Millions are planning to travel to the Kingdom of Saudi Arabia for the Hajj, which begins October 13. The challenge? To keep everyone healthy in the country at the epicenter of the 2012 outbreak of the Middle East respiratory syndrome coronavirus (MERS-CoV), according to a Special Plenary Session on Emerging Infections at IDWeek 2013.
This is especially concerning in that much about MERS-CoV remains unknown, making it difficult to predict its future course, said Ziad A. Memish, MD, deputy minister of health for public health in Saudi Arabia and director of the World Health Organization (WHO) Collaborating Centre for Mass Gathering Medicine.
The first case was reported from Saudi Arabia in September 2012, with an outbreak in Jordan in April 2012 retrospectively identified. As of October 2, 2013, there are 130 laboratory confirmed cases of MERS-CoV infection and 58 deaths (45%), 23 (18%) of whom have been healthcare workers. A total of 108 cases and 47 deaths have occurred in Saudi Arabia alone (9 additional cases and 2 deaths await WHO confirmation), with the greatest number in Riyadh.
Cases of MERS-CoV have also been reported in the United Kingdom, Germany, France, Tunisia, Italy, the United Arab Emirates, and Qatar, in travelers or in those exposed to travelers. Among those who have died, 74% have had underlying comorbid conditions. Approximately 75% of patients have ben male and the median age is 50 years (range, 2–94 years).
Dr. Memish, who is also the chair of the Hajj executive preventive medicine committee, outlined what is known thus far about patterns of transmission: sporadic community cases, with presumed non-human exposure; family clusters (contact with infected family members); and healthcare acquired, both between patients and from patients to healthcare workers. Fifteen specific clusters have been identified.
MERS-CoV causes two distinct forms of disease, severe disease in the primary index cases, the immunocompromised, in those with underlying conditions, and primarily older patients; and mild/asymptomatic disease in the secondary cases, the young, and in the previously healthy.
Genomic sequencing has shown that transmission patterns are more complex than previously believed. Also not clear is whether additional introductions are from undetected cases or zoonotic events, added Dr. Memish, who is also a professor in the College of Medicine, Al Faisal University and King Saud University in Riyadh. For example, although camels and bats remain under suspicion as the mode of transmission, other animals—including livestock, stray dogs and cats, pet birds, and rodents—have not been ruled out, nor has food items such as dried and fresh dates and water sources.
David L. Swerdlow, MD (CAPT, USPHS), incident manager, Centers for Disease Control and Prevention (CDC) MERS Coronavirus Response and associate director for science, National Center for Immunization and Respiratory Diseases, Atlanta, GA, provided the US response to MERS-CoV, noting its similarity to the SARS coronavirus a decade ago.
The CDC has established a four-tier national surveillance plan (0–3), ranging from no cases in the U.S., threat of importation, and low risk of large-scale outbreak to an index case in the U.S. without endemic country exposure or efficient transmission of several generations from an imported case. A total of 44 states in the U.S. have been approved for MERS-CoV testing using rRT-PCR assays.
Dr. Swerdlow emphasized hospital implementation of standard, contact, and airborne precaution infection prevention and control recommendations, with N95 respirators used if available and airborne infection isolation rooms established. These recommendations are similar to those for SARS, in that MERS-CoV has a high mortality rate, human-to-human transmission, unknown modes of transmission, and there is no vaccine or chemoprophylaxis.
He shared information targeted specifically at the approximately 12,000 U.S. visitors who have requested visas for the Hajj. This includes public health communications for inbound and outbound travelers to the Arabian peninsula on the CDC travel website and flyers for distribution on flights returning from the Middle East that details what MERS symptoms should prompt a visit to a doctor.
Richard Besser, MD, ABC News chief health and medical editor, New York, NY, emphasized that as with any pandemic, the importance of communication cannot be underestimated. And, “without total transparency, you've not going to have the trust” of the public. Dr. Besser was acting director of the CDC in 2009, during which time he led the agency's response to the H1N1 influenza pandemic.
The Kingdom of Saudi Arabia Ministry of Health has recommended that the elderly, children, pregnant women, and those with chronic diseases, weakened immune systems, and terminal illnesses not attend Hajj this year. Of the 3 million pilgrims expected, 1.7 million will arrive from outside the Middle East, the majority from Indonesia, India, and Pakistan.