Middle East respiratory syndrome coronavirus (MERS-CoV)
Last edited 04/2019
Middle East respiratory syndrome (MERS) is a viral respiratory disease caused by a novel coronavirus (Middle East respiratory syndrome coronavirus, or MERS-CoV) that was first identified in Saudi Arabia in 2012
- MERS-CoV is a zoonotic pathogen that causes respiratory infection in humans,
ranging from asymptomatic to severe pneumonia (1)
- in dromedary camels, the virus only causes a mild infection but it spreads efficiently between animals
- the dromedary camel is the only animal species that has been reported to transmit this virus to humans
- although the clinical manifestations, as well as transmission, are remarkably
different in MERS-CoV-infected humans and dromedary camels, the viruses
isolated from these two species are highly similar, if not indistinguishable
- indicates that host factors play a significant role in MERS-CoV
pathogenesis and transmission
- indicates that host factors play a significant role in MERS-CoV
pathogenesis and transmission
- Coronaviruses are a large family of viruses that can cause diseases ranging
from the common cold to Severe Acute Respiratory Syndrome (SARS)
- transmission:
- most of human cases of MERS-CoV infections have been attributed to human-to-human
infections in health care settings - however current scientific evidence
suggests that dromedary camels are a major reservoir host for MERS-CoV
and an animal source of MERS infection in humans (1,2)
- however, the exact role of dromedaries in transmission of the virus and the exact route(s) of transmission are unknown - strains of MERS-CoV that are identical to human strains have been isolated from dromedaries in several countries, including Egypt, Oman, Qatar, and Saudi Arabia
- the virus does not seem to pass easily from person to person unless there is close contact, such as occurs when providing unprotected care to a patient
- health care associated outbreaks have occurred in several countries,
with the largest outbreaks seen in Saudi Arabia, United Arab Emirates,
and the Republic of Korea
- most of human cases of MERS-CoV infections have been attributed to human-to-human
infections in health care settings - however current scientific evidence
suggests that dromedary camels are a major reservoir host for MERS-CoV
and an animal source of MERS infection in humans (1,2)
- clinical features:
- typical MERS symptoms include fever, cough and shortness of breath.
Pneumonia is common, but not always present. Gastrointestinal symptoms,
including diarrhoea, have also been reported
- some laboratory-confirmed cases of MERS-CoV infection are reported
as asymptomatic, meaning that they do not have any clinical symptoms,
yet they are positive for MERS-CoV infection following a laboratory
test
- most of these asymptomatic cases have been detected following
aggressive contact tracing of a laboratory-confirmed case
- most of these asymptomatic cases have been detected following
aggressive contact tracing of a laboratory-confirmed case
- some laboratory-confirmed cases of MERS-CoV infection are reported
as asymptomatic, meaning that they do not have any clinical symptoms,
yet they are positive for MERS-CoV infection following a laboratory
test
- typical MERS symptoms include fever, cough and shortness of breath.
Pneumonia is common, but not always present. Gastrointestinal symptoms,
including diarrhoea, have also been reported
- prevention and treatment:
- no vaccine or specific treatment is currently available - however several MERS-CoV specific vaccines and treatments are in development
- treatment is supportive and based on the patient's clinical condition
- prognosis:
- approximately 35% of reported patients with MERS-CoV infection have died (2)
Reference:
- Widagdo W et al. Host Determinants of MERS-CoV Transmission and Pathogenesis.Viruses. 2019 Mar 19;11(3)
- World Health Organization. Middle East respiratory syndrome coronavirus (MERS-CoV) (Accessed 19/3/19).