#coronavirus

COVID-19

Transmission After Recovery

By Charles Li, MD

Background

COVID-19 is becoming harder to avoid as case numbers rise. It's one of the most infectious viruses and it can be fatal to some.

You've probably heard that COVID-19 can be transmissible without noticeable symptoms.

But, what about after you get symptoms? How long should you wait before seeing other people if you get COVID-19?

Researchers in Taiwan conducted one large study that sheds some light into how the question of infectiousness after contracting COVID-19.

Study 1: Transmission vs. Time

Researchers followed 100 patients with confirmed COVID-19. They studied how often those who came in contact with these patients got COVID-19 themselves.

They found that after 5 days of recovery, there were no cases of transmission.

0/852

COVID-19 transmission after 5 days of recovery

results

days after recovery

0.6%

attack rate

range: 0.6% - 1.6%

days after recovery

attack rate

range: 0-0.4%

prospective study

n=100

2761 contacts

The findings of this study suggest that most transmission of COVID-19 occurred at the very early stage of the disease or even before the onset of symptoms, and the secondary clinical attack rate among contacts decreased over time as symptoms developed and progressed.

Cheng, 2020 JAMA Int. Med

"For most persons with COVID-19 illness, isolation and precautions can generally be discontinued 10 days after symptom onset and resolution of fever for at least 24 hours, without the use of fever-reducing medications, and with improvement of other symptoms."

Transmission in the household

You spend more time with those at home, share more things, and you may be in closer physical contact as well.

As expected, those who you live with are at a much higher risk of getting COVID-19 compared to casual contacts outside of the home if you get COVID-19.

% Infected

Household

4.9% (2.3-9.3)

Healthcare Workers

0.9% (0.4-1.9)

Prospective

n=100

2671 contacts

The attack rate was higher among household (4.6% [95% CI, 2.3%-9.3%]) and nonhousehold (5.3% [95% CI, 2.1%-12.8%]) family contacts than that in health care or other settings.

Cheng, 2020 JAMA Int. Med