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To contain the spread of Covid-19, Alaska is planning to triple its number of contact tracers. Utah has retrained 150 state employees. And New York and other states are hiring thousands of people.

And that, health experts say, might not be enough.


To suppress their epidemics to manageable levels, countries around the world have turned to contact tracing — tracking down people who might have been exposed to the coronavirus to ensure they don’t pass it to others, a way of stalking routes of viral spread and severing them before they reach more people. And, to varying degrees, it has worked. But, for it to succeed in the United States, experts are cautioning that it’s going to take more people, more money, and more cooperation than the country has in place.

“We’ve never had something at this scale,” said Marcus Plescia, chief medical officer of the Association of State and Territorial Health Officials. “And clearly we need a lot more people to take this on.”

Ultimately, the hope is that, together with speedy and widespread testing and isolating cases, contact tracing can help keep outbreaks at a wieldy simmer, and buy the country time until better drugs and vaccines arrive. If the U.S. so far has been in a defensive stance against the virus — shutting down large swaths of the economy in the process — contact tracing is a way to go after the virus and keep it at bay.


But some experts fear that the technique might not work as well in the U.S. as it has in other countries.

Many Americans may not understand they might be asked to quarantine for up to two weeks if they’ve been exposed, introducing logistical questions about how they wall themselves off from their families and avoid losing their jobs. People who have the virus might resist cooperating with tracers and divulging where they’ve been and with whom they’ve had contact. Experts wonder how compliant the public will be given that some individual responses to the pandemic — whether people wear a mask or feel they have a right to shop, drink, and worship when and where they want — have become political statements.

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Beyond that, although the number of cases the country is reporting is down from its peak, there are still some 20,000 new Covid-19 infections each day. That’s a lot of people to interview, and a lot of contacts to hunt down, and there are only so many tracers hired so far. Former government health officials have suggested the Trump administration should deploy as many as 180,000 tracers.

“It’s clear that you can do a lot of control if you do contact tracing really well,” Marc Lipsitch, an epidemiologist at Harvard’s T.H. Chan School of Public Health, said last month. But if there are too many cases, or testing limitations mean you can’t identify cases quickly enough, “it’s easy to overwhelm a relatively constrained group of people.”

In March, states began instituting versions of lockdowns because surveillance systems to follow the virus — including testing and tracing — could not keep up. As the virus was racing through communities, the only way to get ahead of it — and to keep it from swamping more hospitals in more communities — was to get everyone away from each other.

But if chains of transmission can be quickly cut by separating just people who have or might have the virus, some semblance of what society used to look like can come back into place. Mass gatherings might not happen, restaurants and stores will have capacities, and some venues will still be shut; if there’s a local burst in cases, some targeted closures will likely be in store. But it could help keep things under control enough that the health system can handle the cases that do occur without requiring broad shutdowns.

On the other hand, if the virus is still circulating widely and states haven’t “staffed up their contact tracing and trained them and have them ready to go, I worry that transmission will start to get out of control,” said Crystal Watson, a public health preparedness expert at the Johns Hopkins Center for Health Security.

Contact tracing is not a new tool. The state and local public health departments being entrusted with it have decades of experience doing it for other diseases, like tuberculosis and HIV. Globally, it’s been used to corral Ebola outbreaks. And although it’s harder to track a respiratory pathogen than one that’s passed through sex or blood, departments can lean on that experience, and just need federal funding and support to ramp up their operations, officials say.

“It’s a very successful track record,” David Harvey, the executive director of the National Coalition of STD Directors, said about the history of contact tracing in the United States. “Overwhelmingly people want to do the right thing. People don’t want to put their families and close contacts at risk for this deadly infection.”

Contact tracing does not need to be perfect to make a serious dent in case counts. If the goal is to keep the number of people getting sick below the point where hospitals are overwhelmed — not to eliminate the virus — not every contact needs to be found and not every person needs to follow recommendations. If health officials can identify half of symptomatic cases of Covid-19 (some people don’t show symptoms), and trace 40% of their contacts, “the ensuing reduction in transmission allows the reopening of economic activities while attaining a manageable impact on the health care system,” a preprint of a modeling study found, relying on transmission dynamics in the Boston area.

If tracing resources are limited, focusing on burgeoning clusters of cases can also be more impactful than taking aim at tendrils of spread, experts say.

“We’re not trying to get rid of Covid-19 altogether — that would be great, but probably unrealistic,” said infectious disease epidemiologist Emily Gurley of the Johns Hopkins Bloomberg School of Public Health. “But even if we can’t stop all transmission, it’s still a really important effort to keep case counts low.”

To build the necessary workforces, states have taken different approaches. Massachusetts is working with the global medical organization Partners in Health, Washington has tapped its National Guard, and Florida has turned to students from the state’s public health schools. Others are relying on temp agencies and job placement programs — a symbiotic partnership at a time when millions have lost their jobs. To train them, groups including Johns Hopkins, as well as the Association of State and Territorial Health Officials and National Coalition of STD Directors, have developed online courses.

To be a contact tracer requires knowing about the disease you’re following, and how to gain people’s trust and coax them through the process of absorbing bad news. Tracers are often the ones who tell people they have the virus, and as they provide information about Covid-19, they also ask about where that person has been in recent days and with whom they’ve interacted. (The Centers for Disease Control and Prevention says that in the case of Covid-19, a contact is someone who spent at least 15 minutes within 6 feet of a case, starting two days before that person started feeling sick.)

Then tracers have to reach out to those contacts and ask them to quarantine. Tracers keep in touch with both cases and contacts, monitoring their health, making sure they have a way to get food, and, in some cases, finding a place for them to stay away from their families. They also have to work quickly; people become infectious just a few days after contracting the virus.

In North Dakota, which has earned praise for its rapid buildup of testing and contact tracing, the majority of both cases and contacts have been willing to help, said Vern Dosch, who’s coordinating the state’s efforts. When contacts are told they’ve been exposed, they are invited to the next drive-through testing event in their area and are asked to quarantine until they get their results back.

“This is a pretty rural state, and the governor has been very, very transparent with them,” Dosch said. “He talks a lot about individual responsibility, and what we say is, if you test positive, you have a responsibility to help us in that tracing effort.” When people are unwilling to help or quarantine, Dosch said, “we just have to say, ‘OK, thank you, we understand that’s your prerogative.’”

Still, he said, “Because we got after it early, we’ve been able to stay in front of things. It’s never perfect — sometimes people don’t cooperate, sometimes we miss a contact — but by and large it’s very effective.”

Experts who are skeptical about how successful contact tracing will be in the United States have noted that even Singapore, with its famed health surveillance system, has at times lost sight of the virus and had to impose physical distancing restrictions (though disruptions to life have been much more limited than those in the United States). In South Korea, a new cluster formed this month among people who had been at nightclubs, sending authorities scrambling to find and test thousands of patrons based on credit card information and cellphone tracking.

Those kinds of technological tactics are likely out of reach in the U.S., where privacy concerns carry more weight. Already in Washington state, for example, Gov. Jay Inslee softened his initial expectation that restaurants would keep a log of diners when they reopened to say that diners could volunteer such information.

Further complicating the U.S. response: State and local health agencies that manage most contact tracing programs have seen the bottom fall out of their budgets as a result of the pandemic’s economic collapse. The earlier coronavirus stimulus bills have included money that public health agencies could use to build digital tools to track the virus, as well as billions for the CDC and state, local, and tribal government responses. But health officials involved say they need dedicated funding to build their contact tracing forces. A bill passed by the House earlier this month included $75 billion specifically for testing and contact tracing, but it is a nonstarter in the Senate, and serious negotiations haven’t made progress.

There is also the increasing politicization of the U.S. pandemic response. In a Twitter thread that inspired a robust debate among public health experts, Keith Humphreys of Stanford University, who is from West Virginia, said his “colleagues are greatly over-estimating the likelihood that the U.S. can mount a national test, trace, and isolate program,” not because of technical prowess, but because of “a political-cultural challenge.” (Humphreys works on epidemiological models for opioid use, not infectious diseases; he acknowledges this is not his specialty.)

“I’ve always been aware when I’m here in Palo Alto that other parts of the country have really big disagreements with things that are taken for granted here,” Humphreys told STAT.

Humphreys said that if someone were to be told they had been exposed to the virus and needed to quarantine for two weeks, that person might respond, “Well, guess what, my rent is due, and I work at a fast-food restaurant and I don’t show up for 14 days, I’m going to get fired. And I think this is all bullshit anyway. I turn on the TV and the president’s not wearing a mask. Don’t tell me what to do.”

In their responses to Humphreys, some public health experts pointed to polls showing that most people supported stay-at-home measures, and that most people, even the majority of people who have lost their jobs, are worried about communities lifting lockdown restrictions too quickly. They say that people flagrantly violating public health recommendations are a vocal minority. Researchers have also found that people have limited contact with others — as well as embraced hand hygiene — without government policies in place. Those individual actions can greatly reduce viral spread.

But it’s possible that willingness to go along with expert advice might be diminishing for some people. A Politico-Harvard poll released last week showed a growing divide between Republicans and Democrats and their feelings toward reopening.

“I’m hoping I’m wrong,” Humphreys said. “I would love for this to work. I’m just afraid that it won’t.”

Experts said that’s one reason why state and local agencies take the lead on contact tracing. Whether people are in a household of immigrants or ideologically distrust the government, they are more likely to cooperate with efforts that don’t directly involve the federal government.

Similarly, epidemiologists also say it’s important to look beyond national case counts. Even if the number of new cases across the country seems daunting, in many communities, there are few enough cases for contact tracing to work if the infrastructure is in place.

“With thousands and thousands of new cases a day, it’s impossible,” said Jeff Engel, a senior adviser at the Council of State and Territorial Epidemiologists. “However, there are some communities that can keep up. They may have 10 to 20 new cases a day. Or a state may have 500 new cases a day, but they’re divided into 20 local health departments, and the local health departments can keep up. And if the local health departments are overwhelmed, they can call on the state for help.”

  • Listen to the medical experts and recognize this is a NOVEL virus. More is being learned as we move forward. But don’t think for a minute that armed with google and listening to non-medical pundits you will have better information that the epidemiologists that have worked in this field every day of their lives for decades. You also need to recognize that medicine is not an exact science. Yes, mistakes were made but leave the finger pointing for later and take heed to what is known that’s effective like wearing masks and social distancing until we have a vaccine.

    • John – the link you provided is to a very poorly written short opinion piece article which contradicts itself multiple times.
      I know, “New England Journal of Medicine” is a high status journal, but the article is not at all good.
      1. First it should be noted, the article is from April 1, 2020 – I am pretty sure that was BEFORE the CDC, which they cite heavily, started recommending face masks for everyone on public.
      2. The second paragraph of the article says “We know that wearing a mask outside of health care facilities, offers little, if any, protection from infection.”

      This statement actively angers me – I do not blame doctors for not knowing how Wuhan virus was spread early on in the epidemic here – though publishing an opinion piece about it without knowing seems pretty arrogant, to be blunt – but to use the language “We know…..” – without ANY citations except unattributed claims of 6 feet distance being sufficient – yes, I know CDC said that too, but who actually did the work to prove it? – that is just an assumption “We know better than all those hysterical people” – which would have to include all the countries in Asia which were doing much, much, much better than the US at containing this, even by April 1 this was obvious.
      3. From the middle of the article – when you are promoting falsehoods, but need to address the truth at some point, it’s best to put it in the middle, which is read and remembered less: “the potential benefits of universal masking have to be balanced against the future risk of running out of masks and THEREBY EXPOSING CLINICIANS TO THE MUCH GREATER RISK OF CARING FOR SYMPTOMATIC PATIENTS WITHOUT A MASK” .

      In other words, “masks don’t work anyway, they don’t protect you, and so you don’t need one, and anyway, we need to keep some on hand so we will be able to protect ourselves later”.

      I do not blame people wanting to protect themselves, signing up to be a nurse or doctor was never understood to carry the risk, not any significant risk, of dying, and doctors are at higher risk -but, while securing as much of the mask stock as they could, they did not need to also tell us not to use them, when that meant the virus spread a great deal more than it otherwise would have.

      We needed to be told early on we needed to do whatever we could to cover our faces – but instead, because there were not enough masks, we were told the opposite.

    • John – one more thing – I am not predicting the future, but all the papers one reads, everything that is being well publicized, give strong reason to believe there will be a vaccine and it could be done, probably, in just a few months.
      Our medical establishment is not going to let them do challenge studies, that is, let people get an experimental vaccine and then be infected with the disease, so that will delay vaccine development by a very long time – like maybe a year – or more – but all the papers seem to claim antibodies are stimulated and the antibodies neutralize the virus. It may be an ongoing problem like the flu is, but we will probably get a much better handle on it. Could probably do so by Fall if the FDA let it happen.

    • The issue with mask is the quality. If it is a cloth mask, it has space between the knit much greater in size than the miniscule vapors in the air from someone sick. This article is current. It supports the fact that most mask will limit the spray from sneezes, coughs and talking.

      But we lose sight of my original comment. We are buried in the weeds and not the forest. My comment starting with the mask discussion was o point out why so many would not support tracing. Everyone and their kid brother has an opinion, publishes the opinion and people read those, a week later it is changed, and then two weeks later it changes again When people lose trust in what they are being told, it is very hard for those making recommendations to get that trust hack.

  • This pandemic started out wrong with Dr. Fauci saying in January that there was nothing to worry about. He told the president the same thing. Then he told USA Today in February there was nothing to worry about, no human to human transmission. Ten he told the country million would get sick and millions could die. Those numbers change multiple times. We were told to wear mask, then we were told mask don’t protect you, they protect the other guy. Then we were told to clean all packages, it could come on the mail, etc. Later they said transmission by that means was limited. We were told that being in the same building with air conditioning could spread the virus widely, and then reports came out that really could not happen. They closed all outside activities, parks, playgrounds, hiking trails, camp grounds, but we were told you had to be within 6 ft of another person. (When your camping, hiking or golfing individually of with someone, can you not stay 6ft from them?), They closed all the small mom and pop stores in rural Bodunk USA where the store might have one or two customers an hour, but left open the big box stores that allowed in hundreds, even with limited access. So with all the opposing views, idiotic closures, apparent rules for favorites that give huge amounts to political campaigns, how can anyone not expect a large number of people to question what is being forced upon them when no clear cut information is given other than “I Said So”. Even with our snowflake generations today, there are still millions that do not accept “Because I Said So” as a reason. Government is not mother. Millions want better than what a 10 year oold kid would be given as a reason.

    • That’s a clipped unfair version of what Fauci said in January. Here is what he actually said: On Jan. 26, Fauci gave an interview to John Catsimatidis, a syndicated radio host in New York. “What can you tell the American people about what’s been going on?” Catsimatidis asked. “Should they be scared?”

      “I don’t think so,” Fauci said. “The American people should not be worried or frightened by this. It’s a very, very low risk to the United States, but it’s something we, as public health officials, need to take very seriously.”

      Fauci reiterated that COVID-19 “isn’t something the American people need to worry about or be frightened about” because, at the time, it was centered in China and the U.S. could screen travelers from that nation.

      But Fauci also twice described the virus as “an evolving situation,” and said, “Every day, we have to look at it very carefully.”

    • Jesse – No doubt Dr. Fauci is being blamed unfairly in some cases, and hindsight is 20/20, and there is plenty of blame for others in our political system, IMO- but can I point out some of the problems with his response? I know he has risked his own life staying in the game at the age of 79, and he has to deal with people who are very exasperating – I appreciate that – but are these unfair criticisms?:

      1. While not wanting a panic, by the middle of January, shouldn’t there have been significant warnings to the public, such as:
      a. People who have returned from China should be monitoring themselves for diseases signs, isolate themselves from others, get surgical masks and wear them, etc.
      b. We do not know how this disease primarily spreads, but a lot of respiratory viruses are airborne, avoid breathing the same air of strangers and anyone who appears sick.
      c. Obviously, the Chinese authorities are very scared, even though they say they are not – from that, it is reasonable to suspect this is a very severe disease.

      2. The claim that face masks were not necessary and if they added any protection, it was very, very marginal. This was not just erroneous, it appears t be a deliberate lie told so people would not hoard the masks. In any case, even if not a deliberate lie, it was clearly baseless when it was made, unless CDC Is giving us bad advice now, and we really do not need the masks – BTW – when you see an article admonishing people to learn from the Swine Flu – that is what my grandmother called it so I do too- of 1918 – consider that in old photos, everyone is covering their faces. I really think they knew better and mislead us.

      3. I have never really researched it, but the claim is made that the failure to get tests was the CDC’s fault.

      I could go on I think. The point is, the government response was not very good – Dr. Fauci is a good man I think, but made very significant mistakes early on. And he is one of the people opposing more aggressive vaccine testing, which will likely have result of us getting a vaccine many months, at the minimum, later than we could get it, with the economy losing a few more trillion and a few hundred thousand more people dying.

      I think complaints are very well justified at this point.

  • We already have anti-vaxers and “freedom” nuts saying they won’t “participate; thus if over 40% of the population won’t cooperate, this will go nowhere. I guess Darwin will prevail in the end….

    • I think most people will get the vaccine – and, without a lot of pressure being applied, it will be kind of like the situation with other vaccines – some people will not take them – and they get sick sometimes, and occasionally die – or their kids die, more likely.

      But when there is an epidemic of some preventable disease like whooping cough, the anti-vaxxers mostly give in, and they get over 80% vaccination or more – not ideal but we are going to see, I think, mandatory CoV2 vaccination to go to almost all jobs and almost all schools- and, probably, all old folks or recovery facilities. And, maybe, all hospitals. At least for any kind of procedure where you can choose the schedule to any extent. And all military. And so on, and so on.
      I do not think it will be a big problem, though the “thinking” of the people who say they will not get it is disturbing, the way they “think” is more of a problem for the country, in the long run, than any disease.

    • I would think most people would get the vaccine as long as it is fully tested and not rushed to market like the Swine flu vaccine in 76-77 where hundreds developed Guillain-Barré after inoculation. This was pretty much the beginning of so many who became anti-vaxers and has just fed on itself ever since. But if you are in the 60% that get the vaccine, then personal responsibility has prevailed. With 60% vaccinated, the exposure for the other 40% is greatly reduced. That would result close to the same number of virus cases as gets the flu and the numbers of deaths would also be about the same

  • tracing seems to work with cases of v.d. and I’m thinking it will work with this virus as well. The issue that seems to keep cropping up is the people who are asymptomatic. No matter what you do there are going to be people spreading the infection without knowing.

  • The issue of asymptomatic cases is significant. The article notes as an aside that “some people don’t show symptoms”. It’s more than some, it’s about half of all cases. Asymptomatic contacts of known cases may be tested and identified, but many asymptomatic cases will never be identified and will infect others. Therefore, I’m not sure that the resources being used to implement this strategy will be justified by the results.

    • In re percent of C-19 cases thought to be asymptomatic. I have seen 20% or thereabouts but never half or almost half . What is your source please?

      I guess it you consider those who have no symptoms but are infectious days before they have any symptoms at all you might be able to say the rate of asymptomatic infectious people is higher than 20 %?

    • Time magazine Covid Update ( free) on line had a article on 27 May stating up to 80% of those with c-19 are without symptoms . So the numbers are all over the place and maybe we will get a better picture as this evolves ( and we get better tests).

    • Another StatNews article on heartbreaking results of testing in San Francisco Latino neighborhood said they found 53% of people testing positive- not clear if it was PCR or antibody, but anyway, a very high percentage in that study.
      I also read young women have the highest rates of asymptomatic cases, for women in their 20s maybe it is well over 50%?

    • My comment above is supposed to say, another Stat article said 53% of people testing positive in an area of San Francisco were asymptomatic. That article’s headline says something about the results of the study being “heartbreaking”.
      That 53% asymptomatic is one of the big reasons I believe contact tracing will have limited value. Many people will get the call from the contact tracer and be told to isolate themselves, but, feeling fine, will not really believe it is important – maybe they stay away from their grandparents, and even parents, but figure, “I am not sick, young people like me do not get really sick, I do not need to stay inside for 3 weeks” and go out and party as usual.

    • Just reading all your comments on asymptomatic cases and how it varies with who wrote the article is just another example for my above comment of why so many people don’t believe what they are being told. In addition, there are many sites that are reporting 1.7- 1.8 million cases and then report 400K to 500K recovered cases with 1.3M- 1.4M active cases. Using new daily cases, you have to go back 56 days to total that many active cases meaning you are sick for at least 56 days. That is false information. Average days of illness is 14 days. Many states do not report recoveries, but the false information also leds to peoples distrust of all information

  • The writer states “ In March, states began instituting versions of lockdowns because surveillance systems to follow the virus — including testing and tracing — could not keep up.“ I don’t recall that justification ever being mentioned at the the time. He did also include, as a seemingly secondary justification, trying to keep hospitals from being overrun with patients, which is how it was actually sold, but no mater what the basis for it, the numbers are starting to make the lockdowns look like a colossal and unnecessary disaster.

    Because the supposed “experts” have been wrong about this virus every step of the way and politicians continue to use it as an excuse to deny individual rights, there’s no way I’d cooperate with contract tracers and no chance I’d ever voluntarily leave my house or do anything other than what I would normally do if I was sick. I’ve had enough and I’m obviously not alone. So yes, contract tracing might have a bit of a problem in the USA.

    • The lockdowns happened because we made a choice, as a country, not to test and do contact tracing. Like most of the information during the pandemic, this was not communicated effectively. I don’t agree that the experts are totally wrong or that politicians need any excuses to deny rights, but I do agree with you that contact tracing would not be effective here.

    • The lockdowns happened because the supposed “experts” relied on flawed models that came nowhere near reality. And are you really saying that politicians should be able to deny people their rights whenever they feel like it?

  • I realize public health professionals are taught contact tracing is very important, and there are many good reasons for that, but the history seems to be for VD and other diseases a person may carry for long periods of time, eg Typhoid Mary situations.
    This disease is gone from the body in a few weeks, and, unlike VD, mamy people will have no idea who they gave infected – no name, face, or even sensation to connect with the event, where they sneezed on the subway and got off and the next passenger inhaled the virus.
    We can do temperature checks at public places to identify more than half the people who are a week or more into infection, and contagious.
    Contact tracing can in theory find the other half of infected persons, who are asymptomatic, but only if you reach them within a month. And of course only if these people, who feel fine, listen to you and isolate.
    Given the cost of lockdown it may be worthwhile to have contact tracing despite all the problems and inescapable inadequacies, but selling it as crucially important?

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