Why the 14-day quarantine?
What you need to know:
- The swab tests are less accurate but when positive will show infection.
Please explain why people are quarantined for 14 days after they come from a high risk Covid-19 country. Why don’t they just check for symptoms and let them go? Mark
Dear Mark,
When a person is exposed to infection, the time taken before they show the first symptoms is called an incubation period. With Covid-19, the incubation period varies from two days to two weeks much as it is typically taken to be five days.
So, the 14-day quarantine is used because about 99 per cent of those sick with the virus will within 14 days develop symptoms making the 14-day quarantine necessary though it does not completely rule out those with mild disease or a few who may get sick after 14 days. As we know more about the virus, this quarantine period is bound to change.
People who are quarantined are checked before they are let go into the public. The danger in this is that the Covid-19 swab tests are only about 60 per cent accurate and can release into the population a big number of undetected but sick people. However, after 14 days, both the deeper nose (nasopharyngeal) tests for the virus RNA particles and substances produced by the body to fight the virus (antibodies) should be done.
Antibody tests are IGM which appears early (around five days after infection) and IGG tests (which indicate that the person is now immune and can be released to the public without fear of being infected). Antibody tests are also useful in those who may have not shown symptoms yet they had gotten infected.
The swab tests are less accurate but when positive will show infection. The antibody tests are more accurate but only show one had been infected and may have now become immune being useful for starting to appear in public and to follow up of the extent of infection in a given people.
Checking travellers from high risk areas and letting them go may release infected people whose swab tests are negative yet they are infected and those who are infected but have not yet formed antibodies. These then require the 14-day quarantine after which both tests are done before being released into the public.
