The experience of learning you have been exposed to someone with COVID-19 can be unsettling, even years into the pandemic. Confusion often arises because public health guidance has evolved significantly as the virus and our understanding of it have changed. However, clear, actionable steps exist for managing your risk, self-monitoring, and determining when and how to test. Following a specific protocol immediately after exposure helps you quickly determine your infection status and implement appropriate precautions for everyone.
Defining Close Contact and Risk Assessment
Identifying a true exposure requires understanding the definition of close contact, which is based on proximity, duration, and the time frame of the infected person’s infectious period. The standard definition of a close contact is being within six feet of an infected individual for a cumulative total of 15 minutes or more over a 24-hour period. This cumulative time frame means short, repeated interactions with the person throughout a single day are added together to determine if the threshold was met.
The risk of transmission is highest starting two days before the infected person’s symptoms began or two days before their positive test specimen was collected, if they were asymptomatic. Several factors can modify the level of risk associated with an interaction. Being in an indoor setting with poor ventilation increases the risk significantly compared to an outdoor encounter. Actions of the infected person, such as coughing, singing, or shouting, also increase the likelihood of virus spread through respiratory aerosols.
Immediate Action Protocol (Testing and Monitoring)
Once you have determined that you are a close contact, the most important action is to begin a rigorous schedule of testing and self-monitoring. Immediately after exposure, you should begin monitoring yourself daily for any signs of illness. The most effective time to test for the virus is at least five full days after your last close contact with the infected individual, with the day of exposure counting as Day 0. Waiting until Day 5 allows the virus enough time to replicate to a detectable level, minimizing the chance of a false negative result.
If you choose to use an at-home rapid antigen test at the five-day mark, a negative result is not definitive because these tests are less likely to detect the virus than laboratory-based tests. The Food and Drug Administration (FDA) recommends that asymptomatic individuals take a series of three antigen tests, performed 48 hours apart, to be confident of a negative result. Nucleic Acid Amplification Tests (NAATs), which include PCR tests, are considered the gold standard for accuracy and usually do not require repeat testing for a single negative result.
Guidance on Isolation and Post-Exposure Masking
For an exposed person who remains asymptomatic and receives a negative test result, public health guidance still recommends taking precautions for a specific period. You should wear a high-quality, well-fitting mask, such as an N95 or KN95, anytime you are around other people indoors for a full ten days following your last exposure. This measure helps prevent potential transmission during the incubation period, even if you are not currently showing symptoms.
If you develop symptoms or receive a positive test result, you must immediately isolate yourself from others to prevent further spread. Current isolation guidance is now based on symptoms rather than a fixed number of days. Stay home until you have been fever-free for at least 24 hours without the use of fever-reducing medication and your other symptoms are improving overall. After meeting these criteria and ending isolation, continue to wear a high-quality mask for an additional five days to protect those around you.
Next Steps if Symptoms Develop
If you become symptomatic, prompt action is necessary regarding potential treatment options. Seek medical evaluation right away, as antiviral treatments are available to reduce the risk of severe illness and hospitalization. These antiviral medications, such as Paxlovid, are most effective when started within five days of symptom onset.
Eligibility for antivirals is limited to individuals at high risk for severe COVID-19, including those who are age 50 or older, are pregnant, or have underlying health conditions like chronic lung disease, heart disease, or a weakened immune system. Your healthcare provider will determine if you meet the specific criteria for treatment. You must also monitor for emergency warning signs that require immediate medical attention:
- Trouble breathing.
- Persistent pain or pressure in the chest.
- New confusion.
- Bluish lips or face.