Jun 27, 2020 - Health

Why coronavirus contact tracing is failing

Illustration of a target in the shape of a virus cell with darts scattered around the target, having missed it.

Illustration: Aïda Amer/Axios

Government virus expert Anthony Fauci told reporters in a press briefing on Friday that contact tracing efforts to contain the coronavirus are "not working."

Why it matters: Without a vaccine, contact tracing of cases is the best tool available to stem the spread of an outbreak. But understaffed public health agencies, privacy concerns, disappointing technology, and the sheer size of the pandemic are limiting the technique's effectiveness.

By the numbers: The public health standard is that a state should have at least 30 contract tracers — public health employees dedicated to investigating the contacts of positive cases — for every 100,000 people during a pandemic. According to a June 25 report by Nephron Research, however, just seven states have met that standard.

  • Another seven have near-term plans to sufficiently increase contact tracing capacity.
  • Many of the states experiencing the biggest surges in cases are well below the recommended number of tracers and have no near-term plans to reach that level. That includes states like Texas, where hospital executives in Houston were warning that ICU use from COVID-19 could soon exceed capacity, and Arizona, where hospitalization numbers are surging.
  • CDC Director Robert Redfield testified that there are 27,000 to 28,000 people doing contact tracing work. That's up from 11,000 at the start of the pandemic, but it is well below the minimum 99,000 tracers that the Association of State and Territorial Health Officials estimated are necessary for the U.S. to safely reopen.
  • Other public health experts believe the true need is closer to 300,000 tracers.

Even those states that have sufficiently beefed up their contact tracing systems are struggling to get people who have tested positive to report whom they were in contact with — or, in some cases, to even pick up the phone.

  • New York state currently has nearly 50 tracers per 100,000 people, the most in the U.S. But in New York City, long the epicenter of the pandemic, contact tracers were only able to successfully complete an interview with about half of all positive cases between June 1 and June 20.
  • That's well below the 75% rate public health experts say is needed to keep an outbreak contained.
  • The situation is worse in other hard-hit cities like San Antonio, which has only received responses from about 300 of the 2,500 cases currently under review.

Context: The U.S. has had great success in the past controlling diseases like HIV and tuberculosis through contact tracing. But COVID-19 would present enormous challenges to even a well-funded and well-staffed national contact tracing effort — which the U.S. assuredly does not have.

  • Unlike tracing the spread of STDs, where contacts can be narrowed down to sexual partners, COVID-19 requires tracers to quiz a positive case for everyone they may have come into contact with, even for a relatively short period of time.

Early hopes that app-based smartphone contact tracing might help have largely gone unfulfilled.

  • At least 60% of the population would need to download such apps for them to be effective, but according to a recent study, just 29% of Americans would consider downloading one.
  • Privacy concerns are a major obstacle to successful contact tracing. South Korea's success in controlling outbreaks was partly due to its use of phone GPS records, credit-card transactions and even security camera footage to augment its contact tracing — methods that would likely not fly in the U.S.
  • Black Americans are being infected and dying of COVID-19 at higher rates, but a long history of discrimination — including by doctors — has made them "less willing to line up and trust a public agency right now, public health included," writes Katelyn Esmonde, a postdoctoral fellow at the Johns Hopkins Berman Institute of Bioethics.

The bottom line: More than four months after the first recorded U.S. COVID-19 cases, the virus is still outpacing our ability and willingness to track it.

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