Mers

Orthocoronavirinae is a subfamily of viruses, also known as coronaviruses, in the family Coronaviridae that includes the genus Coronavirus. It is a Helical Symmetry Virus with genome consisting of single-stranded RNA wrapped capsid. Its morphology is formed by viral spikes, glycoproteins that cross the pericapsid, called S-proteins, with hemagglutinating and fusion properties. A protein coating consisting of the M (matrix) protein is interposed between the nucleocapsid and pericapsid. There are seven viruses belonging to this family capable of infecting humans. They all cause respiratory diseases, including colds, pneumonia and bronchitis, but three in particular cause very serious and sometimes fatal respiratory infections:

• Sars-Cov 2: a new coronavirus identified as the cause of coronavirus disease in 2019 (COVID-19) that started in Wuhan, China, in late 2019 and has spread worldwide;
• Mers-CoV coronavirus identified in 2012 as the cause of Middle East respiratory syndrome (MERS);
• Sars-CoV identified in 2003 as the cause of a severe acute respiratory syndrome outbreak that began in China in late 2002.

MERS-CoV is zoonotic: that is, it develops in animals and is later transmitted to humans.
Since the emergence of the disease in 2012, research has continued to identify the main perpetrators of infection in humans. Epidemiologically, camels have emerged as the main source of infection in humans, while investigations in several countries, including Europe and South Africa, have brought to attention the high viral load of MERS-CoV in fecal samples from some bat species.
Transmission from an infected patient to a healthy one is also possible, typically by direct contact or through infected particles (droplets) emitted during breathing. Contagion by indirect route, following contact with contaminated materials and surfaces, is also possible.

The outbreak of MERS-CoV infection in Saudi Arabia resulted in many infections and deaths. From the main outbreak, the virus subsequently spread to neighboring countries in the Middle East, including Qatar, Bahrain, Kuwait, Tunisia and Jordan. The outbreak also spread to Europe, North Africa, Southeast Asia, and the United States through infected travelers returning from the Middle East. During the MERS-CoV outbreak, cases of infection were reported in 27 countries, 12 of which were located in the Eastern Mediterranean region. A total of 1,227 cases of MERS-CoV, were reported in Saudi Arabia from June 2012 to December 2015; of these, 728 patients recovered and 549 died from the infection.

Symptoms observed among documented cases of MERS-CoV infection include cough, fever, rhinorrhea (the runny nose), shortness of breath, gastrointestinal symptoms, nausea, vomiting, fatigue, and muscle aches. In severe cases it causes respiratory failure. However, there are some confirmed asymptomatic cases.
MERS-CoV causes more severe complications in immunocompromised patients with a history of diabetes and lung disease because these individuals are more prone to acquire the infection.

Identification is complicated in the early stages of the disease by the nonspecificity of symptoms. Pneumonia may allow it to be distinguished, but it is not always present. Infection may be suspected if symptoms have appeared in the two weeks following a trip to the Middle East.
Diagnosis is mainly by two means: serologic tests, which measure the presence of antibodies following an infection, and tests based on PCR techniques, which detect the presence of virus components in the body.

There is no approved therapy for SARS and MERS infections. To date, the main management strategy for MERS-CoV is administration of antipyretics and analgesics, maintenance of hydration, and respiratory support by mechanical ventilation or extracorporeal oxygenation.
If a patient with MERS-CoV has bacterial co-infection, treatment is directed to the use of antibiotics.
Recent publications have discussed several options (interferon, lopinavir/ritonavir, ribavarin, inhibitors of virus replication, e.g., cilcophilin inhibitors, and MERS-CoV neutralizing antibodies), but none of these agents has been shown to be definitively effective.
Recently, three human monoclonal antibodies, m336, m337 and m338, targeting the receptor-binding domain (CD26/DPP4) of the MERS-CoV glycoprotein spike were successful in neutralizing the virus.

To prevent the spread of MERS-CoV infection, it is essential to adopt the use of PPE (Personal Protective Equipment): gowns, gloves and the use of surgical masks. Local health authorities must enforce compliance with appropriate precautions when treating patients infected with MERS-CoV.
For travelers to endemic regions, the risk of acquiring MERS-CoV infection is relatively low. This risk depends on any contact with infected patients in health facilities, with dromedaries or products derived from these animals.
In many Persian Gulf countries, camelids are valuable sources of milk and meat. Moving and trading infected animals, particularly camels, is a potential source of spreading MERS-CoV infection. Travelers should therefore avoid contact with sick people or animals and follow personal hygiene measures in addition to paying attention to the consumption of safe, cooked and still-warm food.
Currently, there is no vaccine available to prevent MERS-CoV infection, and it is not known whether vaccinations introduced with the Sars-Cov19 pandemic also confer cross-protection for MERS-CoV infection.