When COVID-19 cases and hospitalizations plummeted in late spring, many large, government-run testing sites from Los Angeles to New York switched to vaccinations or shut down.
That was before the highly contagious delta variant became the dominant coronavirus strain, accelerating cases, hospitalizations and deaths.
Americans are getting checked for the virus at a pace of more than 1 million tests each day, according to Johns Hopkins University. Some experts said it's harder to find testing appointments than it was last winter, when large, drive-thru sites fueled more than 2 million daily tests.
Consumers can test themselves with rapid antigen kits sold at national chain pharmacies and retailers, but they're selling as fast as they are stocked. Antigen test makers scaled back manufacturing this spring and are hustling to fire up factories to meet rising demand.
"Everyone assumed when we got to April and May there wouldn’t be a need for widespread testing," said Michael Osterholm, director of the Center for Infectious Disease Research and Policy at the University of Minnesota.
Coronavirus positivity rates surge to winter levels
Some worry the high percentage of positive tests in the USA means too many people are foregoing testing because it's too hard to get an appointment.
More than 10% of U.S. residents who have been tested for the coronavirus since the first week of August were infected. That's double the World Health Organization's benchmark for sufficient testing, according to Johns Hopkins University. When the positive rate is higher than the WHO’s target rate of 5%, that might mean only the sickest individuals are getting tested, and others who show minor or no symptoms are spreading the virus without knowing it.
“Positivity has climbed to highs that we haven’t seen since the big winter surge,” said Jennifer Nuzzo, an epidemiologist and senior scholar at the Johns Hopkins Center for Health Security. “Positivity for me, above all, is a measure of whether we are doing enough testing. As it starts to creep up, that suggests we need to cast a wider and wider net to find infections.”
In addition to the delta variant, several factors appear to be influencing the uptick in testing.
Some large school districts are testing incoming students, teachers and staff as the fall semester begins. More employers mandate that workers either get vaccinated or submit to periodic testing. The Centers for Disease Control and Prevention said even vaccinated people should get tested if they're exposed to someone with COVID-19, a reversal from its earlier guidance.
In a summer of freedom after months of social distancing, some travelers are going to destinations that require proof of a negative test. Some concert promoters and musicians want only fans who are vaccinated or have tested negative.
Nuzzo anticipated the current testing crunch in the spring when she had to be tested before a work-related event. She searched a health department website for government-run clinics that could deliver results within 48 hours. Many sites had shut down. Others had limited hours and required appointments.
After hours of searching, she found an urgent care clinic that was busy with people who needed a quick test for travel or other purposes.
Many health departments faced a dilemma last winter: steer limited resources to testing centers or prepare to administer vaccines. Nuzzo worries that shutting down testing sites left the nation vulnerable to the surge, leaving public and private sites scrambling to restore capacity.
Concern about keeping up with demand for tests this fall
Even in Vermont, where 85% of eligible residents have received at least one vaccine dose, hospitals and health providers are processing more coronavirus tests, said Dr. Christina Wojewoda, laboratory director at the University of Vermont Medical Center in Burlington.
She said her lab returns most test results within 48 hours, even amid a recent surge from people suspected of having COVID-19, those undergoing elective surgeries and travelers who need a negative lab test to enter Canada.
She sees potential challenges this fall as the state launches COVID-19 resource centers that offer testing and vaccination under one roof. The centers will be open weekdays and will have some weekend appointments. Wojewoda anticipates more testing requests this fall as people develop symptoms of common viruses such as flu and respiratory syncytial virus, or RSV.
"I’m concerned going into fall, where we are going to have more people presenting with symptoms, that we might overwhelm those systems," said Wojewoda, who chairs the College of American Pathologists' microbiology committee.
Quest Diagnostics, one of the nation’s largest laboratories, reported a steady climb in the number of tests and the percentage of positive results in recent weeks. Demand is “comparatively high” at labs in the Southeast and Southwest, where the New Jersey-based company said it will add testing capacity to keep pace.
Unlike last summer, when demand overwhelmed labs such as Quest and delayed results for a week or more, the company said this week that most samples are processed in one day.
In virus hot spots such as Palm Beach County, Florida, private testing centers have been overwhelmed with a surge of people seeking testing. Turnaround times have swelled to five to seven days.
Palm Beach County reopened testing centers this week, including one at the South County Civic Center near Delray Beach, and opened new ones, including at the Palm Beach County branch library in Palm Beach Gardens. Even more testing centers will open over the coming days, according to county officials.
Test makers step up production
Private companies that sell direct-to-consumer tests have been surprised by the sudden resurgence in demand.
On June 1, Abbott Laboratories, which makes versions of the Abbott BinaxNow rapid antigen test, warned investors of "significantly lower recent and projected COVID-19 diagnostic testing demand" due to fewer cases and plentiful vaccines. The company closed a factory in Gurnee, Illinois, that manufactured the tests, a move that eliminated 2,000 jobs, the Daily Herald reported.
A company spokesman said Abbott seeks to "scale up on a dime" to make enough BinaxNow tests for retailers such as CVS and Walgreens. The kit is for sale on Amazon, but it could take up to three weeks to get one.
"We’re hiring people and turning on parts of our manufacturing network that were idled or slowed when guidance changed and demand plunged," Abbott spokesman John Koval said. "While there will be some supply constraints over the coming weeks as we ramp back up, we are putting resources from all over the company to help meet this unprecedented demand."
Quidel CEO Douglas Bryant said retail sales for the San Diego-based company's home coronavirus tests have increased tenfold over the past few weeks. "We're obviously ramping up manufacturing again," he said.
The company makes the Sofia brand antigen testing machines used in health care settings such as doctor's offices and urgent care clinics. It also makes the QuickVue home test, sold at Walgreens. Antigen tests detect proteins found on the surface of the coronavirus; the PCR tests used in labs detect a virus's genetic material.
Like others, Quidel anticipated less testing this spring and summer. The company must contact its suppliers and reorder material. Those suppliers, in turn, must hire workers and restart production.
Quidel makes 2 million to 3 million home tests each week and anticipates making 4 million to 5 million tests per week soon.
"All of the manufacturers, including ourselves, are in a state of flux," Bryant said. "We’re trying to pivot and trying to react quickly, doing the best we can without a whole lot of real understanding of what’s going to be needed."
Contributing: Jane Musgrave, The Palm Beach Post
Ken Alltucker is on Twitter as @kalltucker or can be emailed at email@example.com.
This article originally appeared on USA TODAY: Why it's harder to find coronavirus tests amid delta variant's surge