Includes all COVID-19 deaths reported from the start of the pandemic up to Feb 3, 2021 (USA), Jan 29, 2021 (UK), Jan 20, 2021 (Italy), Feb 9, 2021 (Germany), Feb 10, 2021 (Spain), Feb 11, 2021 (France), or Feb 3, 2021 (South Korea).
Important update: Healthcare facilities
CDC has updated select ways to operate healthcare systems effectively in response to COVID-19 vaccination. Learn more
Understanding Exposure Risks
Learning about how COVID-19 spreads and the factors that can increase or decrease that risk can help you make informed choices.
The questions below are written in past tense to help you assess the likelihood that you were infected when you were around a person with COVID-19. If multiple factors below indicate higher transmission risk, you should follow the steps for what to do if you are exposed.
You can also ask yourself the same questions, but about future interactions with others, to help you decide what prevention actions to take. If multiple factors below indicate higher transmission risk, you should consider adding more prevention actions.
Longer exposure time increases the risk of transmission (for example, contact longer than 15 minutes is more likely to result in transmission than two minutes of contact).
Activities like coughing, singing, shouting, or breathing heavily due to exertion increase the risk of transmission.
Being around people who are symptomatic increases the risk of transmission.
If one person was wearing a mask, the risk of transmission is decreased, and if both people were wearing masks, the risk is substantially decreased. Risk is also lower if the mask or respirator is a type that offers greater protection.
More outdoor air can decrease the risk of transmission. Being outside would be lower exposure risk than being indoors, even with good ventilation and filtration; both of those options would be lower risk than being indoors with poor ventilation or filtration. See the Interactive Home Ventilation Tool.
Poorly ventilated indoors
Being closer to someone who is infected with COVID-19 increases the risk of transmission. Crowded settings can raise your likelihood of being close to someone with COVID-19.