Middle East respiratory syndrome coronavirus
The Middle East respiratory syndrome coronavirus (MERS-CoV) is a new beta virus strain of an animal coronavirus that was first identified in Saudi Arabia in September 2012.
This novel coronavirus differs from the previously identified coronaviruses such as the SARS coronavirus (SARS-CoV), which caused the 2003 SARS outbreaks.
There is still much to be investigated, but it is considered likely that this virus originated from an animal source.
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Coronaviruses are enveloped RNA viruses from the Coronaviridae family and part of the Coronavirinae subfamily. With its characteristic surface, the virions appear as a crown like image under the electron microscope and so the viruses are named after the Latin word corona, meaning 'crown' or 'halo'.
In animals the viruses infect the respiratory and gastrointestinal systems as well as occasionally affecting the liver and the neurological systems.
The human coronaviruses mainly infect the upper respiratory and gastrointestinal tract. They often result in upper respiratory tract infections (simple colds) in humans, causing mild illnesses usually of short lasting nature with a rhinitis, cough, sore throat, as well as fever.
Occasionally, the viruses are able to cause more significant lower respiratory tract infections in human with pneumonia; this is more likely in immunocompromised individuals, people with cardiopulmonary illnesses, as well as the elderly and young children. Only very rarely do the humans viruses cause severe disease, like sever acute respiratory syndrome.
The five coronaviruses types which affect humans are alpha (229E and NL63), beta (OC43), HKUI1 and SARS-CoV - although the latter is best considered an animal virus that has only rarely infected humans.
In humans, the transmission of coronaviruses between an infected individual and others can occur via respiratory secretions. This can happen either directly through droplets from coughing or sneezing, or indirectly through touching contaminated objects or surfaces as well as close contact, such as touching or shaking hands.
There are currently no vaccines or specific treatments for the coronaviruses. Hence, in order to reduce the risk and prevent the spread of infections, simple preventative measure are: good respiratory hygiene, including washing hands; avoiding touching one's eyes, mouth and nose; sanitary disposal of oral and nasal discharges as well as avoiding contact with sick people.