Middle east respiratory syndrome

Middle East Respiratory Syndrome (MERS) Virus –an important zoonotic coronavirus of 21st centuryBy

Dr. Iqra Zaheer (PhD Pathology Scholar)

Respiratory viruses are an emerging threat to global health security and have led to worldwide epidemics with substantial morbidity, mortality, and economic consequences. Since the severe acute respiratory syndrome (SARS) pandemic, in September 2012 the World Health Organization (WHO) reported two cases of severe community-acquired pneumonia caused by a novel human β-coronavirus, subsequently named the Middle East respiratory syndrome coronavirus (MERS-CoV). Middle East respiratory syndrome (MERS) virus causes an extremely lethal respiratory disease. MERS-CoV has a RNA genome and taxonomically belongs to the group of betacoronavirus.

Recent Outbreaks:

The virus was first isolated from a patient who died from a severe respiratory illness in June, 2012, in Jeddah, Saudi Arabia. As of May 31, 2015, 1180 laboratory-confirmed cases (483 deaths; 40% mortality) have been reported to World Health Organization. In 2015, Saudi Arabia banned the slaughter of camels during Hajj pilgrimage, after a surge in deaths from the MERS virus linked to the animals.The largest known outbreak of MERS outside the Arabian Peninsula

occurred in the Republic of Korea in 2015 and was associated with a traveler returning from the Arabian Peninsula.

Both community-acquired and hospital-acquired cases have been reported with little human-to-human transmission reported in the community. Although most cases of MERS have occurred in Saudi Arabia and the United Arab Emirates, cases have been reported in Europe, the USA, Qatar, Jordan, the United Kingdom, Germany, France, Tunisia, and Italy in people who travelled from the Middle East or their contacts.

Risk Factors:

This virus can infect individuals of any age. Based on what researchers know so far, people with pre-existing medical conditions may be more likely to become infected with MERS-CoV, or have a severe case. Pre-existing conditions from reported cases for which we have information have included diabetes; cancer; and chronic lung, heart, and kidney disease. Individuals with weakened immune systems are also at higher risk for getting MERS or having a severe case.

People who have a recent history of visiting Arabian Peninsula, having close contacts with travelers from Arabian Peninsula, having close contacts with confirmed MERS cases, health care personnel who are not using standard control precautions or people who have close contacts with animals are at an increased risk.

Reservoir of the Virus:

MERS-CoV likely came from an animal source in the Arabian Peninsula. In addition to humans, MERS-CoV has been found in camels in several countries. It is possible that some people became infected after having contact with camels. However, more information is needed to figure out the possible role that camels and other animals may play in transmission of MERS-CoV.

Clinical Signs:

Clinical features of MERS range from asymptomatic or mild disease to acute respiratory distress syndrome and multiorgan failure resulting in death, especially in individuals with underlying comorbidities. Most people confirmed to have MERS-CoV infection have severe acute respiratory illness with symptoms of fever, cough and shortness of breath. About 3 to 4 out of every 10 people reported with MERS die. Most of the people who die have an underlying medical condition.However, some infected people have mild symptoms (such as cold-like symptoms) or no symptoms at all.

Pathological lesions:

Frontal chest radiograph obtained after a week of infection shows bilateral multifocal patchy airspace disease with predominant perihilar distribution and multiple areas of cavitation. MERS-CoV infection also causes desquamation of pneumocytes in humans, contributing to alveolar dysfunction, oedema and haemorrhage. Uncontrolled inflammation, fluid accumulation and developing fibrosis severely compromise gas exchange and leads to respiratory failure

Management of MERS-CoV:

According to the guidelines of center for disease control (CDC) following preventive measures must be adopted:

Wash your hands often with soap and water for 20 seconds. If soap and water are not available, use an alcohol-based hand sanitizer.

Cover your nose and mouth with a tissue when you cough or sneeze, then throw the tissue in the trash.

Avoid touching your eyes, nose and mouth with unwashed hands. Clean and disinfect frequently touched surfaces and objects, such as doorknobs.

No specific antiviral drug treatment or vaccine exists for MERS. The U.S. National Institutes of Health is exploring the possibility of developing a vaccine against this infection. Individuals with MERS can seek medical care to help relieve symptoms. For severe cases, current treatment includes care to support vital organ functions. Nevertheless, infection prevention and control

measures are crucial to prevent spread in health-care facilities. MERS-CoV continues to be an endemic, low-level public health threat.

Conclusion:

Treatment options for Middle East respiratory syndrome virus are limited. Hence, strict precautionary measures must be employed to control and prevent the virus otherwise it has the ability to exhibit mutation in order to have an increased interhuman transmissibility, further enhancing its pandemic potential.