Coronaviruses (CoV), including SARS CoV, are single-stranded RNA viruses and belong to the family Coronaviridae. Coronaviruses are spread by the respiratory route.Severe acute respiratory syndrome (SARS) is caused by SARS coronavirus (SARSCoV), which is spread by the respiratory route and through the ingestion of aerosolized faeces via contamination of the hands and environment. Close contact with asymptomatic person poses the highest risk of infection. In recent outbreak, mostcases occurred in hospital workers or family members in contact with cases.
Infection usually occurs in winter orspring and is associated with upper respiratory tract infection (a ‘cold’). SARS CoV isthought to have been transmitted from civet cats (a variety of wild cat) to humanswith subsequent human-to-human spread, while 2019-nCoV isthought to have been transmitted from civet cats (a variety of wild cat) to humanswith subsequent human-to-human spread.Coronaviruses are considered infectious while patients are symptomatic. Patients are most infectious at the onset of respiratory symptoms.Coronavirus infection is more severe in elderly persons. The most severe and fatalinfections with SARS have been in elderly persons.
Coronaviruses produce a range of symptoms from asymptomatic infection to upperrespiratory symptoms (a ‘cold’), malaise and fever. Brochiolitis and other lowerrespiratory tract symptoms occur in a few patients of all ages.Coronaviruses can be found in the human gut, but there is no clear diseaseassociation.CoV causes high fever, dry cough, shortness of breath, myalgia, headache and diarrhoea. Chest X-rays show pneumonia or respiratory distress syndrome. Symptoms are usually severe enough to warrant hospital admission. The overall fatality rate was 15% in previous outbreaks, higher in elderly patients and those with other respiratory conditions; less than 1% in persons less than 24 years of age, 6% in those aged 25–44 years, 15% in those aged 45–64 years and greater than 50% in persons aged 65 years or older.
Parainfluenza, RSV, adenovirus and other respiratory viral infections have to beconsidered in the differential diagnosis of respiratory CoV infections.SARS CoV infection has to be distinguished from influenza and other causes ofpneumonia and high fever. Coronaviruses are not usually tested for in most hospital laboratories, although some regional virology laboratories may include coronavirus detection in their respiratory PCR diagnostic test repertoire. They are difficult to grow in cell culture. SARS CoV is only diagnosed in specialist reference laboratories with Category 4 diagnostic facilities. In England there are two centres of the Health Protection Agency, in London and Porton Down, that are able to undertake this work. Infection can be diagnosed by PCR or serological tests
Treatment and Control
There is no specific treatment for coronavirus infections, including SARS CoV. Management of the latter requires supportive management of the presenting symptoms. The spread of coronaviruses can be reduced by strict handwashing after patient contact. The use of gloves, face masks, aprons and goggles will reduce the risk of transmission. Isolation in single rooms or cohort nursing reduces the risk to other patients.
Severe acute respiratory syndrome is less infectious than influenza but symptomatic patients should be nursed in side rooms, preferably negative-pressure rooms, with gloves, aprons and a respirator mask conforming to at least European standard EN149:2001 FFP3. If a suitable respirator mask is not immediately available, use a surgical face mask (see latest guidance).
WHO’s standard recommendations for the general public to reduce exposure to and transmission of a range of illnesses are as follows, which include hand and respiratory hygiene, and safe food practices:
- Frequently clean hands by using alcohol-based hand rub or soap and water;
- When coughing and sneezing cover mouth and nose with flexed elbow or tissue – throw tissue away immediately and wash hands;
- Avoid close contact with anyone who has fever and cough;
- If you have fever, cough and difficulty breathing seek medical care early and share previous travel history with your health care provider;
- When visiting live markets in areas currently experiencing cases of novel coronavirus, avoid direct unprotected contact with live animals and surfaces in contact with animals;
- The consumption of raw or undercooked animal products should be avoided. Raw meat, milk or animal organs should be handled with care, to avoid cross-contamination with uncooked foods, as per good food safety practices.
Can pets at home spread the new coronavirus (2019-nCoV)? At present, there is no evidence that companion animals/pets such as dogs or cats can be infected with the new coronavirus. However, it is always a good idea to wash your hands with soap and water after contact with pets. This protects you against various common bacteria such as E.coli and Salmonella that can pass between pets and humans.
Are antibiotics effective in preventing and treating the new coronavirus? No, antibiotics do not work against viruses, only bacteria. The new coronavirus (2019-nCoV) is a virus and, therefore, antibiotics should not be used as a means of prevention or treatment. However, if you are hospitalized for the 2019-nCoV, you may receive antibiotics because bacterial co-infection is possible.
Are there any specific medicines to prevent or treat the new coronavirus?
To date, there is no specific medicine recommended to prevent or treat the new coronavirus (2019-nCoV). However, those infected with the virus should receive appropriate care to relieve and treat symptoms, and those with severe illness should receive optimized supportive care. Some specific treatments are under investigation, and will be tested through clinical trials. WHO is helping to accelerate research and development efforts with a range or partners.