NOEL KING, HOST:
The White House doesn't appear to be doing contact tracing of President Trump, who has COVID, or of people in his circle, despite the fact that we've heard public officials say repeatedly, if you want to beat coronavirus, you test, you trace, then you isolate, and despite the fact that at least 12 people who are in the president's inner circle have also tested positive. Susie Welty of the University of California, San Francisco, has been working with public health officials on contact tracing. She's here to give us a little bit more information on what should be happening. Thanks so much, Susie.
SUSIE WELTY: Yes, good morning, Noel. In a normal situation, the public health lab, the county or local health jurisdiction would get those lab results directly and call each of those cases and do something what's called case investigation, talk to them about their symptoms, but then also ask who they've been in contact with in the 48 hours preceding their symptoms. That's their infectious period. So they would gather information about people who have been within 6 feet for more than 15 minutes. And that doesn't have to be consecutive. And in some jurisdictions, it's irrespective of mask wearing. So we would gather that information, and then the contact tracers would call all of those close contacts. In this case, obviously, it's across many jurisdictions. They didn't get tested in labs that would go get reported to county labs. So the county or D.C. metropolitan would not have access to their lab results. So, really, the local health jurisdictions are operating in the dark here without information about cases that have tested positive either in their jurisdictions or have been in their jurisdictions since they were testing positive.
KING: All right. You're drawing an interesting distinction there, which is that normally local officials handle this. The White House would seem to be its own separate entity just given the nature of what the White House is. But in an ideal world, would the White House be providing this information to public health officials here in Washington, D.C.?
WELTY: Definitely. You know, the people that work in the White House who have been exposed are most likely D.C. residents or residents of some jurisdiction nearby. And, you know, many of those people that were attending, the press secretary, others, they're citizens and, you know, part of that community. So they should - I would think that the local health jurisdiction should be involved with contact tracing because it's more than just the White House bubble. People leave and go home to their families and, you know, go out to restaurants and other things.
KING: The White House is reportedly emailing people who came in contact with the president and others in his circle who are infected. Is that a good step?
WELTY: It's more than nothing, I mean, it's informing people, but I think, you know, the essence of contact tracing and the reason that we've been kind of slow to uptake technology is that you really need to make that connection. You really need to explain to someone what this means. You need to help them understand why quarantine is important. So anyone who was in close contact with the president should be in quarantine for 14 days. If they were any other citizen, that's what would be expected of them, according to the CDC guidelines, because, as we know, they can - that incubation period is 14 days. So they could test positive any time from 14 days from their exposure. So when I'm calling people in San Francisco, you know, even if they test negative, I tell them you still have to stay home for 14 days because you could test positive at any point and be infectious in that period between when your last negative test is and when you're - and your next positive one is.
KING: With the president back at the White House now, even though he is still infected with the coronavirus, would you recommend that the White House start doing something now, even if they're just beginning?
WELTY: Yeah. Well, I mean, we saw even yesterday more people testing positive, so we know we're not - they're not out of that, you know, incubation period. I think there's still a lot they could do. And I think there's possibly, you know, more positives coming or more positives we haven't heard of. But it was definitely - you know, he was a very prolific superspreader. He was all over the country and in lots of closed spaces with lots of people. So it would stand to reason, especially I would look at New Jersey very closely. He probably had a very high viral load when he was in that room with those donors. So I would look at those time frames when he was probably very infectious.
KING: And we should say that even though contact tracing is important, or public health officials say it is, very little of it is happening nationwide or less than we might expect or want. Why is it such a challenge?
WELTY: I think, you know, it requires several things. It requires a government that, you know, listens to their scientists, which we have in San Francisco, a mayor who listened to the scientists immediately and declared a state of emergency quickly. It requires public trust, people who trust the government, people who trust each other and wear masks. And it requires resources to be able to do the testing. The testing turnaround has to be very quickly. And so I think those are things that are required and they're expensive.
KING: OK. Susie Welty of the University of California, San Francisco, who's working as a contact tracer, thanks for taking the time.
WELTY: Thank you. Bye. Transcript provided by NPR, Copyright NPR.