Q.Browse the information about COVID-19 with respect to: a. Structure b. Modes of infection c. Preventive measures d. Treatment.

COVID-19 is caused by the coronavirus SARS-CoV-2 - a spherical, enveloped virus with a single-stranded RNA genome and the spike (S) proteins that give the 'corona' - spread mainly by respiratory droplets and aerosols, prevented by masks, distancing, hand hygiene and vaccination, and treated with supportive care (oxygen when needed) and, in selected cases, antiviral and anti-inflammatory drugs. …

Suggested plan.

1. Sources - WHO, the Ministry of Health and Family Welfare and ICMR pages; record the date of every fact, since guidance changed as the pandemic progressed.
2. a. Structure - a spherical, enveloped virus about 80-120 nm across; a single-stranded positive-sense RNA genome wound with nucleocapsid (N) protein; a lipid envelope carrying the membrane (M) and envelope (E) proteins and the club-shaped spike (S) proteins that bind the ACE2 receptor on human cells and give the crown-like look. Draw and label it, and compare it with the HIV structure in section 10.3 (both enveloped RNA viruses, but HIV is a retrovirus with reverse transcriptase).
3. b. Modes of infection - respiratory droplets and finer aerosols released when an infected person coughs, sneezes, talks or breathes, especially indoors; contact with contaminated surfaces followed by touching the eyes, nose or mouth; spread is possible from people without symptoms.
4. c. Preventive measures - well-fitting masks in crowded or closed spaces, physical distancing, frequent hand washing or sanitiser, ventilation, covering coughs, testing and isolation of cases and quarantine of contacts, and vaccination (the Indian programme used vaccines such as Covishield and Covaxin) - note how each measure breaks a link in the chain of transmission described in (b). …