Page 111 - Journal of Special Operations Medicine - Winter 2015

Middle East Respiratory Syndrome

Akira A. Shishido, MD; Andrew Letizia, MD

ABSTRACT

Middle East respiratory syndrome (MERS) emerged in Jordan in April 2012. Between April 2012 and May
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the Arabian Peninsula in 2012, and subsequently spread 2015, MERS-CoV has been reported in multiple countries
to other countries in Europe and Asia, and to the United in the Middle East, Europe, and Asia, and in the United
States. As of August 2015, the disease has infected 1,400 States. The cases in Europe and the United States were
1–3
patients, of whom 500 have died, yielding a 36% mor- imported by patients with travel history to the Middle
tality rate. The exact mode of transmission is unknown East and, fortunately, caused no sustained transmission. 1–3
and there are no proven treatments. While the overall However, an ongoing outbreak in the Republic of Korea
case rate for MERS has been low, its presence in coun- grew from a single patient with travel history to Saudi
tries that house US troops, unknown mode of transmis- Arabia who infected close family contacts and healthcare
sion, and high mortality rate make it a significant health workers, resulting in sustained human-to- human trans-
concern among US military personnel. mission and a large hospital-based outbreak. 1–3

Keywords: Middle East respiratory syndrome; coronavirus; The source and transmission of MERS-CoV are un-
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epidemiology; clinical presentation known. However, studies have found evidence of viral
sequences similar to MERS-CoV in bats, and MERS-
CoV antibodies have been detected in camels. Further
investigations have shown a high rate of seropositivity
Introduction
in camels in the Arabian Peninsula, with no evidence of
Middle East respiratory syndrome (MERS), caused by infection in cows, goats, or sheep. To date, the only ac-
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a novel coronavirus (MERS-CoV), emerged in the Ara- cepted zoonotic source of transmission of MERS-CoV is
bian Peninsula in 2012. The first patient recognized to camel to human. The nature of transmission from cam-
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have the disease died of a severe respiratory infection in els to humans has yet to be characterized, but proposed
a hospital in Jedda, Saudi Arabia, in June of that year. mechanisms have included exposure to nasal discharge,
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Since that index case, the infection has been reported saliva, feces, urine, dairy products, and meat handling.
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in multiple countries throughout the Middle East and Human-to-human transmission has proved to be a great
caused a healthcare facility-based outbreak in the Re- challenge to healthcare personnel in facility-based out-
public of Korea in 2015. As of August 2015, the in- breaks. Transmission between patients and healthcare
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fection has yielded 1,401 confirmed cases worldwide providers is presumed to occur largely via droplets and
and 500 deaths, with a mortality rate of approximately contact, though airborne transmission may be possible
36%. The disease can present as a febrile respiratory as well. 2
1–3
illness and rapidly progresses into fulminant respiratory
failure and acute respiratory distress syndrome (ARDS). Clinical Presentation
The exact source and mechanism of transmission are
unknown. While the overall operational threat remains The clinical manifestations of MERS-CoV infections
low, the cryptic and severe nature of this infection and vary immensely, from asymptomatic to severe pneu-
its prominence in the Middle East poses a serious con- monia complicated by ARDS, septic shock, multiorgan
cern for deployed US military personnel. Prevention, failure, and death. The incubation period appears to be
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awareness, recognition, and supportive care of the ill- approximately 5 days but can be as long as 2 weeks af-
ness will be critical to forward deployed troops. ter initial infection. Most symptomatic patients present
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with fever, chills, cough, and dyspnea, as well as sore
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throat, myalgia, and arthralgia. Up to 25% of patients
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Epidemiology
also report vomiting and diarrhea. Greater than 90% of
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Since the first reported case of MERS, a retrospective patients will initially present with focal or diffuse infil-
study identified an earlier hospital-based outbreak in trates on chest radiography. Laboratory abnormalities
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