17^th Feb: 70 new cases on board the cruise ship in Japan. Nearly 1 out of 10 passengers and crew (9.6%) have tested positive for the virus so far (355 cases out of 3,711 passengers and crew).  The 952-foot cruise ship carries the highest infection rate of the coronavirus anywhere in the world.

China has imposed quarantines across Hubei province, locking down over 56 million people, in order to stop COVID-19 from spreading.

Villages in Vietnam with 10,000 people, close to the nations capital, have also been placed under quarantine after six cases of the new coronavirus were identified there. The locking down of the commune of Son Loi, about 40 kilometres from Hanoi, is the first mass quarantine outside of China since the virus emerged from central China late last year.

If you lock down COVID-19 infected people with non-infected people, the transmission will be around 10%. This will still be insufficient to start the herd immunity chain. The idea of lock down probably was to develop herd immunity in the locked down population but with R0 value of 3, it looks impossible.

Over the last four days, the number of new cases in China has been declining.  

Limitations of quarantine

1. The people on lockdown are kept under a 14-day quarantine. If they are placed together and if anyone is diagnosed with the infection during that period, the quarantine will add another 14 days.
2. In China, the lock down has not been lifted so far.
3. The longer several thousand people are cohoused, it goes on to propagate waves of infection.
4. A better way is to divide the people into smaller groups and quarantine them separately.
5. Why quarantine children <15 years of age when the virus is not risky for them.
6. Why not separate elderly people with comorbid conditions at high risk of death and quarantine them separately in one-to-one or small groups.
7. Ventilation system can connect one room to the other. There has been concern that the coronavirus can spread through pipes.
8. Stress and anxiety suppress the immune system, thus rendering people more vulnerable to contracting the virus. 
9. Why not quarantine them in open sunlight.

Dr KK Aggarwal

President CMAAO, HCFI and Past National President IMA