CME FOR THE MONTH SEPT2013

MERS

          MIDDLE EAST RESPIRATORY SYNDROME- CORONAVIRUS                (MERS-COV).

Corona viruses are a group of viruses that infect the respiratory tract of both humans and animals. Some corona viruses affect the digestive system. The virus has a crown-like projection on its surface, which is how it got its name. There are many different species of the virus. Human corona virus was discovered in 1965 and accounts for 10 percent to 30 percent of common colds. It affects all age groups and is most common during the winter and early spring. In young children and older people, human corona virus can affect the lower respiratory tract as well. Many people get corona virus for a second time within four months after having it the first time. Scientists believe this is because the antibodies created to fight the corona virus only protect a person for four months. In addition, there are many different types of human corona virus and the antibodies from one type will not protect you from another type. The incubation period of the virus -- meaning the time it is in the body before symptoms appear -- is usually two to four days, and the infection caused by human corona virus is usually mild. A relatively small amount of information is known about human corona viruses because most of them do not grow in cultured cells, making it difficult to study them. This particular strain of corona virus has not been previously identified in humans. There is very limited information on transmission, severity and clinical impact with only a small number of cases reported thus far

The SARS outbreak in 2002 was believed to be caused by a new type of corona virus that was similar to the one that affects cats. Due to its contagious nature, SARS became a world epidemic, spreading to 32 countries and infecting 8,459 people. Many of the people who contracted SARS also developed pneumonia, and over 800 people died as a result of SARS.

Corona viruses  are species in the genera of virus belonging to the subfamily Coronaviridae in the family Coronaviridae. Corona viruses  primarily infect the upper respiratory and gastrointestinal tract of mammals and birds. Four to five different currently known strains of corona viruses  infect humans. The most publicized human corona virus, SARS-CoV which causes SARS, has a unique pathogenesis because it causes both upper and lower respiratory tract infections and can also cause gastroenteritis. Corona viruses  are believed to cause a significant percentage of all common colds in human adults. Corona viruses  cause colds in humans primarily in the winter and early spring seasons. The significance and economic impact of corona viruses  as causative agents of the common cold are hard to assess because, unlike rhinoviruses (another common cold virus), human corona viruses are difficult to grow in the laboratory. Corona viruses can even cause pneumonia, either direct viral pneumonia or a secondary bacterial pneumonia.

In 2003, following the outbreak of Severe acute respiratory syndrome (SARS) which had begun the prior year in Asia, and secondary cases elsewhere in the world, the Organization issued a press release stating that a novel corona virus identified by a number of laboratories was the causative agent for SARS. The virus was officially named the SARS corona virus (SARS-CoV).

The epidemic resulted in over 8,000 infections, about 10% of which resulted in death.^[3] X-ray crystallography studies performed at the Advanced Light Source of Lawrence Berkeley National Laboratory have begun to give hope of a vaccine against the disease "since [the spike protein] appears to be recognized by the immune system of the host." Corona viruses are enveloped RNA viruses from the Coronaviridae family and part of the Coronavirinaesubfamily. 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 corona viruses 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 corona viruses  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 corona viruses  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 corona viruses . 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.

Corona viruses are a large family of viruses that includes viruses that may cause a range of illnesses in humans, from the common cold to SARS. Viruses of this family also cause a number of animal diseases. 

MIDDLE EAST RESPIRATORY SYNDROME CORONAVIRUS  corona virus which is now called the Middle East respiratory syndrome corona virus (MERS-CoV). This new beta virus strain of an animal corona virus was identified in September 2012 in individuals with severe acute respiratory illness occurring in the Arabian Peninsula, some of whom were transferred for care to hospitals in Europe. Retrospectively some infections have also been detected in humans with severe acute respiratory illness in Jordan in the spring of 2012. This corona virus differs from the previously identified corona viruses such as the SARS corona virus (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.

More on corona virus infections

In chickens, the infectious bronchitis virus (IBV), a corona viruses , targets not only the respiratory tract but also the uro-genital tract. The virus can spread to different organs throughout the chicken.

Corona viruses  also cause a range of diseases in farm animals and domesticated pets, some of which can be serious and are a threat to the farming industry. Economically significant corona viruses  of farm animals include porcine corona viruses  (transmissible gastroenteritis corona viruses , TGE) and bovine corona viruses , which both result in diarrhoea in young animals. Feline Corona viruses : two forms, Feline enteric corona viruses  is a pathogen of minor clinical significance, but spontaneous mutation of this virus can result in feline infectious peritonitis (FIP), a disease associated with high mortality. There are two types of canine corona viruses  (CCoV), one that causes mild gastrointestinal disease and one that has been found to cause respiratory disease. Mouse hepatitis virus (MHV) is a corona viruses  that causes an epidemic murine illness with high mortality, especially among colonies of laboratory mice. Prior to the discovery of SARS-CoV, MHV had been the best-studied corona viruses  both in vivo and in vitro as well as at the molecular level. Some strains of MHV cause a progressive demyelinating encephalitis in mice which has been used as a murine model for multiple sclerosis. Significant research efforts have been focused on elucidating the viral pathogenesis of these animal corona viruses , especially by virologists interested in veterinary and zoonotic diseases.