From giving advice recently to a friend who was symptomatic, got tested and was told to expect a 3-5d delay, I've come to realize a gap in our prevention approach. The advice on preventing transmission if you are infected is mainly provided through contact tracing.

That's good but it's not enough. Especially with these kinds of delays, it could be almost a week from the time someone feels the need to get tested (symptoms, poss contact, whatever) until they might get a call from contact tracers if positive.

In the interim, if they were truly a SARS-CoV-2 infection, they would likely have passed through their peak period of infectiousness, the 4-6 days or so immediately before and after symptom onset we believe.

If they don't know what to do in the time between symptom onset and test results, they may miss opportunities to prevent transmission. High numbers of household clusters (by far the most common KNOWN source of clustered cases, partly ascertainment) suggest that's happening.

So what should people do if they feel ill but have no test result? The goal should be to reduce spread in household and beyond. Symptoms should prompt behavior similar to that prompted by a positive test. Reduce risk in the home:

1) sleep solo in separate room if at all possible. Sharing sleeping quarters/bed a well documented (and understandable) risk for trasmission. 2) mask in the house while infection status unknown. Ideally others in house should do same 3) ventilate & use air purifiers if available

And prevent transmission outside the house -- stay home from work/school/shopping. This is all obvious but in my experience it's really not being communicated to those who need it -- those who feel sick or have an "unofficial" exposure and are waiting for test results