(With inputs from Dr Monica Vasudev)

931: How long does it take to get sick?

The “incubation period” is the time from exposure to the virus and the onset of symptoms. For COVID-19, the incubation period ranges from 1 to 14 days. But most people who develop symptoms usually do so 4 to 6 days after exposure.

932: How long are you infectious?

The infectious period is the time one can spread the virus to someone else. For COVID-19, emerging evidence suggests that the infectious period may start 1 to 3 days before one develops symptoms. The most infectious period is considered to be 1 to 3 days before symptom onset, and in the first 7 days after symptoms appear. Some people may remain infectious for longer period though.

Common symptoms for COVID-19, such as fever, cough and fatigue, usually last for about 9 to 10 days, but this can be longer.

In case of viruses, the higher the viral load (the more virus circulating in the body), the higher the risk of transmission through known transmission pathways.

A study in Hong Kong evaluated the viral load in 23 patients diagnosed with COVID-19. It found higher viral loads in the first week of illness.

A study from China evaluating 76 hospitalized patients noted that by 10 days after symptom onset, mild cases had cleared the virus. This means no virus was detectable through testing. However, severe cases have much higher viral loads and many continue to test positive beyond the 10 days after symptoms start.

The more severe the illness and the higher the viral load, the longer one can shed the virus and is infectious.

933: When are you no longer infectious?

If someone has been symptom-free for 3 days and had developed their first symptoms over 10 days prior, they are no longer considered to be infectious. However, it is not certain whether people are infectious when they have recovered but the virus can still be detected in their bodies.

A study from Hong Kong noted that the virus could be detected for 20 days or longer after the initial onset of symptoms in one-third of patients tested. A study from China found the virus in a patient’s fecal samples five weeks after the first onset of symptoms.

However, the detection of the virus doesn’t necessarily mean that the person is infectious. More studies with larger sample sizes are needed to obtain better understanding of the question.

934: Should you get tested again before going back into the community?

People who have been under self-quarantine, because they had contact with a confirmed case of COVID-19 and have completed their 14-day quarantine period without developing symptoms, can return to the community. They do not need to be tested prior to returning to the community. But, they should continue to practice social distancing and good hygiene as a precaution.

Re-testing people who have experienced mild illness, and have recovered from COVID-19 is not recommended as of now. A person is considered safe to return to the community and discontinue self-isolation if they are no longer infectious, i.e., they developed their first symptoms more than 10 days prior and have not experienced any symptoms for at least 3 days (72 hours).

People who have been hospitalized with more severe illness have different testing requirements before discharge. They need to undergo two swabs tests taken 24 hours apart to check if they have cleared the virus. If both the swabs are negative, the patient can be discharged and does not require further self-isolation.

If one or both tests are positive but the person is well enough to be discharged, they must continue to self-isolate for at least 10 days since they were discharged from hospital and they have not experienced any symptoms for at least 3 days.

Testing requirements differ for people working or living in high-risk settings. If someone works or lives in a high-risk setting, they must consult with their healthcare provider on re-testing requirements.

[https://theconversation.com/how-long-are-you-infectious-when-you-have-coronavirus-135295]

INDIA

What was earlier criteria for discharging COVID-19 patients?

The earlier criteria for discharging RT-PCR positive case: (a) chest radiograph has cleared and (b) two consecutive negative test results on RT-PCR.

What is the new discharge policy for COVID-19 patients?

For mild/very mild/pre-symptomatic cases

Patient can be discharged after 10 days of symptom onset and with no fever for 3 days

No need for testing before discharge

Patient to be advised to isolate himself/herself at home and self-monitor his/her health for further 7 days

Such patients should always use triple layer medical mask. They must stay in an identified room and away from other people, especially elderly and those with co-morbid conditions like hypertension, cardiovascular disease, renal disease, etc. Strict personal hygiene should be maintained and they should self-monitor their health with daily temperature monitoring and report promptly if they develop any deterioration of symptom.

For moderate cases

Patient can be discharged: (a) if asymptomatic for 3 days and (b) after 10 days of symptom onset

No need for testing before discharge

Patient to be advised to isolate himself/herself at home and self-monitor his/her health for further 7 days

For severe cases

Clinical recovery

Patient tested negative once by RT-PCR (after symptoms resolve)

Dr KK Aggarwal

President CMAAO