In New Zealand, identifying close contacts quickly and having them isolate has been credited as a big reason, along with widely available testing, that the country has almost eliminated COVID-19 within its borders.
So who exactly is a close contact? How much contact, exactly, does it take to be considered one? If you rode a bus for a few moments with someone who later tested positive, does that count? What if you spent longer than you expected in the coffee shop, waiting to pick up your pre-order?
The CDC has some answers on this one, in its guidance for contact tracers. It says that a close contact is any individual who as within 6 feet of an infected person for at least 15 minutes, starting from two days before illness onsetuntil the time the patient is isolated. Or, if the person who tested positive was asymptomatic, you had that much contact with them two days prior to their positive test.
If youve been a close contact, then self-isolation is the next step. You may also get tested, and the contact tracer or case investigator should be able to help you figure out how to help with that, even if you live in an area with limited testing or other health resources. Youll also want to do the stuff you know to domonitor symptoms and avoid people at higher risk for severe illness.
In the ideal situation, people who are identified through contact tracing get checked in on via calls or video conferencing to see how theyre doing and help them monitor their health.
Of course, the 6-feet/15-minutes definition doesnt mean that if you were with someone for 12 minutes, you dont have to be concerned. As weve seen so far, the novel coronavirus doesnt like to follow traditional rules. So always assume that the virus can be transmitted from you and to you and take the appropriate steps to stop the spread.