Coronaviruses

Coronaviruses are RNA viruses, that get their name from their typical appearance. Human coronaviruses are common causes of  cold ,  upper respiratory tract infections' , but also serious diseases such as SARS (severe acute respiratory syndrome, originating in China), MERS (Middle East Respiratory Syndrome, native to Saudi Arabia) or COVID-19. The infection spreads mainly  'droplets' .

These are enveloped (+) ssRNA viruses. From the surface of their lipid envelope protrude spikes, which have lytic, hemagglutinting and adsorption activity. The envelope of the virus originates from the host membrane endoplasmic reticulum. There are 4 main subgroups: alpha (9E, NL63), beta (OC43, HKU1, MERS-CoV, SARS-CoV), gamma and delta.

Common human coronaviruses
Common human coronaviruses include types 229E, NL63, OC43, HKU1, and usually cause mild to moderate upper respiratory tract infections, such as the common cold. It is transmitted from an infected person to a person by coughing and sneezing, by direct contact with the patient (touch, handshake), indirectly by contact with infected objects and rarely by contact with the patient's stool. Symptoms of the disease include secretion from the nose, headache, cough, sore throat, fever and a feeling of "illness". The disease usually lasts a short time and most people experience it during their lifetime. People may experience more coronavirus infections during their lifetime. The highest incidence is in autumn and winter, but the infection can occur at any time of the year. Human coronaviruses sometimes also cause lower respiratory tract diseases such as pneumonia or bronchitis, more often in people with cardiopulmonary disease, a weakened immune system, children and older adults.

Other human coronaviruses
Other human coronaviruses that originally caused infections in animals include  MERS-CoV ,  SARS-CoV  and the new coronavirus  2019-nCoV .  'MERS'  ( Middle East Respiratory Syndrome ) was first reported in Saudi Arabia in 2012, from where it spread to other countries. It manifests by fever, cough, shortness of breath, pneumonia and is accompanied by high mortality (3-4 patients out of 10 die). MERS still appears in the Arabian Peninsula.  'SARS'  ( severe acute respiratory syndrome ) appeared in China in 2002 and has been associated with fever, chills, body pain, pneumonia, but has not been reported in humans since 2004.

A new coronavirus, SARS-CoV-2, was reported in January 2020 and was first identified in China as the cause of the COVID-19 epidemic in Wu-Chan.

Diagnosis

 * History - information about travel to the risk area;
 * typical clinical presentation;
 * PCR detection from upper and lower respiratory tract samples and blood serum.

Prevention
Vaccines against COVID-19 are available. The risk of infection can be reduced by thorough hand washing, avoiding contact with eyes, nose or mouth with unwashed hands, avoiding close contact with patients. The risk of droplet infection can be reduced by using respirators, masks or half masks with particle protection category P3.

Treatment
There is no causal treatment. Most common human coronavirus infections resolve spontaneously without treatment. In more severe cases, symptomatic treatment is possible (treatment of fever, pain, etc.).

Related articles

 * SARS
 * RNA viruses
 * MERS