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How Accurate Are Daily Positive Case Counts? Dr. Mallika Marshall Answers Your COVID-19 Questions

BOSTON (CBS) — Dr. Mallika Marshall is answering your coronavirus-related medical questions. If you have a question, email her or message her on Facebook or Twitter.

Dr. Mallika is offering her best advice, but as always, consult your personal doctor before making any decisions about your personal health.

Bob writes, "I went to a New Year's Eve party where not many people wore masks. I felt like I had a cold on Saturday and tested positive. I'm feeling much better, so how long should I quarantine?"

If you tested positive, you need to isolate for a full five days after your symptoms started. If you're feeling fine after that, the CDC now says you can come out of isolation as long as you continue to wear a mask around others. As a precaution, you may choose to do another rapid antigen test on day 5. If negative, you're probably no longer contagious (though you still need to wear a mask for an additional 5 days). If positive, you probably are still contagious and therefore should continue to isolate at home for another 5 days.

Patty asks, "With the case counts rising rapidly and the # of home tests available, how accurate are the daily counts? I personally know a minimum of 10 people who have home-tested positive!"

Yes, I think the numbers being reported significantly underestimate the number of true positive cases out there. People who test positive with rapid home antigen tests, who don't have confirmatory PCR tests, are not being counted. We are definitely in an Omicron surge right now. Hopefully, we will hit a peak in the next week and the numbers will start to rapidly decline. In the meantime, wear a good quality mask in public and stay vigilant.

Sue says, "I had mild COVID around Christmas. I am now negative with no symptoms. Can I get the booster now or must I wait longer?"

You can get a booster once you're out of isolation and feeling better. You don't necessarily need to rush out and get a booster since you were recently infected but probably should within 2-to-3 months of your infection.

An anonymous viewer writes, "My partner has a large face with a beard he can't shave. He can't get a good fit with a KN95 mask. Would he be better off with a 3-ply medical mask with a cloth mask to hold it in place or an ill-fitting KN95 mask?"

I think whatever mask "arrangement" provides the best seal is the way to go. I think either two medical masks or a medical mask with a cloth mask on top would be better than a poorly fitting KN95 mask. You can go to projectN95.org for mask suggestions.

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