COVID-19 is an infectious disease caused by a recently discovered new strain of coronavirus. The first outbreak was seen in Wuhan, China, in December 2019. The outbreak was declared a Public Health Emergency of International Concern on 30 January 2020.
WHO announced a name for new coronavirus disease on February 11, 2020: COVID-19. In COVID-19, CO refers to corona, VI refers to the virus, D refers to disease and 19 refers to the year of the outbreak. Common human coronaviruses are 229E, NL63, OC43, HKU1, MERS- CoV, SARS- CoV, SARS-CoV- 2. Covid-19 is caused by SARS-CoV-2.
Morphology
Severe acute respiratory syndrome-associated coronavirus 2 is enveloped with protein and contains non- segmented, single-stranded, positive- sense ribonucleic acid as genetic material. Due to surface protein projections, under electron microscopy, the virus resembles a crown. Corona is a Latin word which means crown.
Transmission
Droplets transmission occurs when respiratory droplets from an infected person are inhaled. Contact transmission occurs when an object or surface contaminated with the virus by an infected person. Subsequent touching of eyes, nose, mouth makes the entry of the virus into the human body. Aerosol transmission occurs when respiratory droplets mixed with air are inhaled largely.
Pathogenesis
The incubation period is from 1 to 14 days. The virus enters the lungs through the transmission. After entering into the lungs it will affect the epithelial cells of alveoli. This leads to alveolar oedema. This causes difficulty in breathing.
Symptoms
The most common symptoms are fever, dry cough, tiredness. The serious symptoms are difficulty in breathing, chest pain. One should seek immediate medical attention if serious symptoms are experienced.
Diagnosis
Nucleic acid testing is done through real-time reverse transcriptase PCR assays. Immunoassay like ELISA can be performed for antibody detection in the infected person. Swabs should be used for nasopharyngeal collections when SARS-COV-2 is suspected.
Treatment
There is no specific antiviral treatment for COVID-19 and currently, no vaccine is available. The treatment depends on the symptoms of the patient. Mechanical ventilation is required when there is difficulty in breathing.
Prevention
Washing hands with soap regularly, using alcohol-based sanitizer, bathing after coming home from outdoors, avoid touching of nose, mouth, eyes frequently, wearing masks while going outdoors, maintain social distance, covering mouth while coughing or sneezing in public. The most important preventive measure is having a strong immune system. So, having a proper and healthy diet is necessary.
Statistics
Till date there are 5.61 million confirmed cases, 2.31 million recovered cases and 351000 deaths.
