Learning about how COVID-19 spreads and the factors that can increase or decrease that risk can help you make informed choices. If you were around a person with COVID-19, consider these factors to help determine the likelihood that you were infected.
If multiple factors below indicate higher transmission risk, you should follow the steps for what to do if you are exposed.
Risk of transmission is increased when:
- Exposure time is longer. Contact longer than 15 minutes is more likely to result in transmission than two minutes of contact.
- A person is coughing, singing, shouting, or breathing heavily due to exertion.
- You are around people who are symptomatic.
- You are not wearing a mask and you indoors with other people who are not wearing masks.
- You are close to someone who is infected with COVID-19. Crowded settings and poorly ventilated indoor spaces can increase the risk of transmission.
Risk of transmission is decreased when:
- One person is wearing a mask. If both people are wearing masks, the risk is substantially decreased.
- Exposure times are short. Contact with someone in passing, or for about two minutes is less likely to result in transmission.
- Activities are outdoors. Keeping a safe distance from people and being in a well ventilated environment lowers the risk of transmission.