Health departments around the United States that are using contact tracers to contain coronavirus outbreaks are scrambling to bolster their ranks amid a surge of cases and resistance to cooperation from those infected or exposed.
With too few trained contact tracers to handle soaring caseloads, one hard-hit Arizona county is relying on National Guard members to pitch in.
In Louisiana, people who have tested positive typically wait more than two days to respond to health officials — giving the disease crucial time to spread.
Many tracers are finding it hard to break through suspicion and apathy to convince people that compliance is crucial.
Contact tracing — tracking people who test positive and anyone they've come in contact with — was challenging even when stay-at-home orders were in place.
Tracers say it's exponentially more difficult now that many restaurants, bars and gyms are full, and people are gathering with family and friends.
"People are probably letting their guard down a little ... they think there is no longer a threat," said Grand Traverse County, Michigan, Health Officer Wendy Hirschenberger, who was alerted by health officials in another part of the state that infected tourists had visited vineyards and bars in her area.
Her health department was then able to urge local residents who had visited those businesses to self-quarantine.
Hirschenberger was lucky she received that information — only made possible because the tourists had cooperated with contact tracers. But that's often not the case.
Dr Anthony Fauci, America's top infectious disease expert, said last weekend that contact tracing simply isn't working in the US.
Some who test positive don't cooperate because they don't feel sick. Others refuse testing even after being exposed. Some never call back contact tracers. And still others simply object to sharing any information.
Another new challenge: More young people are getting infected, and they're less likely to feel sick or believe that they're a danger to others.
While older adults were more likely to be diagnosed with the virus early in the pandemic, figures from the Centres for Disease Control and Prevention show that the picture flipped almost as soon as states began reopening. Now, people 18 to 49 years old are most likely to be diagnosed.
Today, the United States reported 38,800 newly confirmed infections, with the total surpassing 2.5 million, according to a tally by Johns Hopkins University. For a few days now, daily reported cases in the US have broken the record set in April. That partially reflects increased testing.
Some states were caught off guard by the surge and are trying to quickly bolster the number of contact tracers.
"Right now we have an insufficient capacity to do the job we need to," Arkansas Governor Asa Hutchinson said recently, announcing he wanted to use federal coronavirus relief funds to increase the number of contact tracers to 900.
Arkansas already has 200 doing the job, but infections have risen more than 230 per cent and hospitalisations nearly 170 per cent since Memorial Day. Businesses that had closed because of the virus were allowed to reopen in early May, and the state further eased its restrictions this month.
In addition to needing more staff to handle rising case numbers, contact-tracing teams also must build trust with people who might be uneasy or scared, said Dr Umair Shah, executive director for Harris County Public Health in Houston, where an outbreak threatens to overwhelm hospitals.
That's difficult to do if infected people don't return calls.
In Louisiana, only 59 per cent of those who have tested positive since mid-May have responded to phone calls from contact tracers, according to the latest data from the state health department.
Just one-third answered within the crucial first 24 hours after the test results. Tracers there get an answered phone call, on average, more than two days after receiving information about the positive test.
Perry Halkitis, dean of the Rutgers School of Public Health, said Covid-19 spreads so fast that contact tracers need to get in touch with 75 per cent of the potentially exposed people within 24 hours of their exposure to successfully combat the spread.
"Is it as good as we would like? Well, obviously not," said Dr. Jimmy Guidry, Louisiana's state health officer. "It's better than not having it."