People with COVID-19 are contagious starting about 1 to 2 days before symptoms begin and remain infectious for up to 8 to 10 days after symptom onset
. The highest contagiousness tends to occur early in the illness, especially around the day symptoms start and peaking around day 4 of symptoms, then gradually decreasing over time
. Most people stop being contagious after about 10 days if their symptoms have improved and they have been fever-free for at least 24 hours without fever- reducing medication
. However, individuals who are severely ill or have weakened immune systems may remain contagious for longer, sometimes beyond 10 days
. In summary:
- Contagious period begins 1-2 days before symptoms.
- Peak contagiousness is within the first 4 days of symptoms.
- Contagiousness usually lasts up to 8-10 days after symptoms start.
- Isolation can typically end after 10 days if symptoms improve and no fever for 24 hours.
- Longer contagious periods possible in severe or immunocompromised cases.
Taking precautions like isolation, mask-wearing, and testing can help reduce spread during this contagious period
