Testing the key to reopening economy, returning life to normal, officials say
But COVID-19 testing is falling short. Here’s what you need to know about different tests and what they tell.
SOUTH JORDAN — Testing for COVID-19 will be crucial to safely reopen the pieces of America now shut down. But it’s a process fraught with inconsistencies and mixed messages, including confusion about the types of tests and who and how many should be tested.
States are testing for SARS-CoV-2, the virus that causes COVID-19, at vastly different rates. Hard-hit New York has well outpaced the rest of the country in not just infections and deaths, but also testing. As of Tuesday, the COVID Tracking Project shows the Empire State had nearly a quarter-million infections, more than 14,000 deaths and had tested about 32,000 people per 1 million population.
In comparison, Utah had conducted 19,824 COVID-19 tests per million people — but was testing at a much higher rate than many states, including some with many more deaths, including California (7,109 tests per million people), Arizona (9,762 tests per million people) and Colorado (8,022 tests per million people).
Nationally, there’s little agreement on how much testing is required to loosen restrictions.
The U.S. needs 1 million tests a day “to be confident the outbreak is contained — which is roughly what the country now does in a week,” Howard Forman, director of the Yale School of Public Health’s health care management program, told Bloomberg.
Experts at Harvard said as many as 20 million tests a day should be administered by midsummer to safely reopen the economy completely. That recommendation by 45 health and economic experts “far exceeds testing recommendations from other health experts, according to The Hill. Former Food and Drug Administration Commissioner Scott Gottlieb has said the country will need to initially conduct up to 3 million tests per week to reopen. A separate estimate from Harvard researchers says the U.S. must conduct between 500,000 and 700,000 tests per day by mid-May to begin reopening.
Two types of COVID-19 tests are important. A polymerase chain reaction, or PCR, test is diagnostic: Health care providers swab an individual’s nasal passage looking for COVID-19 antigens indicating infection. Some labs have developed their own PCR tests for the virus, so there’s variation though the tests are vetted for accuracy.
The other type of test, called serology because it analyzes blood, looks for signs of previous infection in the form of antibodies. It’s believed — but not yet proven — that individuals who have the antibodies showing they had COVID-19 have some immunity from future infection — though whether that’s true or how long any immunity lasts is not yet known, Dr. Todd Vento, an infectious disease expert at Intermountain Medical Center, told the Deseret News.
The serology tests are still being developed and tested; they are expected to be more widely available in the near future.
Utah tackles testing
Utah testing got a big boost with the announcement Tuesday that Merit Medical and Deseret Laboratories in St. George have answered the governor’s plea to to help boost supplies needed to see who has COVID-19.
Lack of nasal swabs has been one of the “pinch points” in the supply chain, Gov. Gary Herbert said. But manufacturing experts at the two companies joined others, including state officials and public health experts, to design and then make collection and specimen kits for testing — including nasal swabs, vials and transport chemicals, as well as biohazard bags.
The kits use reagent created in Utah using a recipe that came from Wyoming, said Herbert, noting the importance of partnerships to overcoming this pandemic.
Fred Lampropoulos, Merit Medical chairman and CEO, said his company is making 10,000 kits a day and will ramp up to 50,000 to meet Utah’s needs first, then hopes to help others in the region and perhaps beyond who need the supplies, which are essential to testing for the virus.
Health officials are hesitant to put numbers to testing goals.
“The key to stopping this pandemic is to make sure that anybody who needs a test for COVID-19 can get one,” said Dr. Angela Dunn, state epidemiologist with the Utah Department of Health.
Herbert, meanwhile, has said he would like “everyone” to get tested.
The state last week opened testing to anyone with one or more of the six symptoms associated with the disease — including cough, fever, shortness of breath, loss of taste or smell, muscle aches and pain, or a sore throat. The first few days after expanding testing criteria, the state continued to see below-capacity demand but has since seen an uptick as they deployed new mobile testing facilities to underserved populations like those in homeless shelters. State officials have also worked with testing locations to implement the new criteria.
Utah is capable of testing as many as 5,000 people per day.
Still, that doesn’t mean officials want everyone tested — at least not yet.
While officials say testing asymptomatic individuals eventually has a place in the state’s response, it could create chaos without a plan that includes serology testing.
The accuracy of PCR testing is “dependent on how many people have the disease in the state right now. So we have such low prevalence right now of COVID-19 that if we do randomized testing across the state, there’s a high risk of false positives,” Dunn explained. “And so that means that you might go get a nasal swab, and if you don’t have any symptoms, and haven’t been exposed to a confirmed case of COVID-19, it can come back positive. And we at public health would treat that as a positive” by recommending isolation and initiating contact-tracing.”
In Salt Lake County — with more than half of Utah’s COVID-19 cases, deaths and tests — the goal for testing is “a bit of a moving target,” said Ilene Risk, epidemiology bureau manager with the county health department.
If each test performed in the county — 31,735 as of Monday — represents one person, that means just 3% of the population has been tested, Risk said. Some have received multiple tests for the virus.
What will really be telling in transmission rate is serology testing, she agreed. Officials are coming to understand the “top of the pyramid” data about those who have been hospitalized or died from the virus. But more mystery remains around the number of asymptomatic carriers and those with minor illnesses.
Serology will be essential to develop a reliable model to understand the virus burden in the community.
ARUP Laboratories already started performing a small amount of serology testing earlier this month on health care workers, but company officials say it will be weeks before the testing will become available to the public.
“I think the burden model I mentioned will be interesting, because it will help us understand just the impact on community transmission. But to get back to the new normal will happen more through our antibody studies, and so that will allow us to understand” how many people have been exposed throughout the state, Risk said.
Upcoming serology testing will play into decisions about loosening social mitigation efforts and reopening businesses locally.
“It would help a great deal. I think it’s the best thing for us to look at at this point,” Risk said.
State officials also see antibody tests as a vital part of their response to the pandemic.
“A key to understanding how much disease and how much spread is going out there is actually going to be antibody testing,” Dunn said. “We’re working right now with the University of Utah and the Centers for Disease Control and Prevention to start antibody testing pilots here in Utah, hopefully within the next week or two, so that we have a better understanding of the actual spread of disease in Utah.”
A national dilemma
National experts say nowhere near enough tests are being conducted to be confident the scope of the crisis or how many people are infected is known.
“Stopping the spread of COVID‑19 requires finding and testing all suspected cases so that confirmed cases are promptly and effectively isolated and receive appropriate care, and the close contacts of all confirmed cases are rapidly identified so that they can be quarantined and medically monitored for the 14-day incubation period of the virus,” a World Health Organization briefing said.
Dr. Ashish K. Jha, director of the Harvard Global Health Institute, wrote in Forbes, “The single most important tool we’ll need is an extensive testing infrastructure. Right now, we’re testing approximately 150,000 people a day. That’s nowhere near enough.”
He said most states are telling those with mild symptoms they don’t need to be tested, but should figure they have COVID-19 and isolate themselves. “This strategy, borne out of a shortage of testing capacity, has meant that we don’t know the true burden of disease, and those quarantining themselves at home are often still spreading it to family members.”
People without symptoms are not tested, so how many could be infecting others is unclear.
“We’re on a battlefield wearing blindfolds,” Jha wrote. “We need enough to test everyone who has symptoms and their contacts, as well as a sample of the people who are asymptomatic to know how much silent disease we are missing.”
Despite gains like those provided by the testing kits being made in Utah, supply shortages remain a well-known factor slowing testing. During a conference call last week, Scott Becker, CEO of the Association of Public Health Laboratories, said public health and commercial labs are close to capacity, while hospital labs lack adequate supplies to test more people. The Food and Drug Administration has tried to help by adjusting some of its rules; it recently relaxed technical requirements for nasal swabs, for example.
Bloomberg noted that the Centers for Medicare and Medicaid Services now pays $100 a test — double what it was — to help labs hire more technicians.
Health systems bill a person’s insurance for COVID-19 testing, and many but not all insurance companies have pledged to cover the full cost of testing. The Coronavirus Aid, Relief, and Economic Security Act and the Families First Coronavirus Response Act both include federal requirements and conditions for providing testing at no cost to those without insurance, according to the Utah Department of Health.
People are encouraged to contact their health insurance company or call the testing locations to ask about costs if they are concerned.
Some experts believe changing how tests are processed could reduce costs, stretch supplies and increase tracking.
Stanford School of Medicine researchers looked back over samples taken months ago that were negative for other upper respiratory infections to see what might have been learned about early spread of COVID-19 by pooling samples in the San Francisco area. Pooling works by combining samples from up to 10 people at a time, reducing the amount of chemistry and other supplies needed to test for the virus. Using that method, they were able to estimate prevalence.
Some experts suggest pooling samples could be effective for deciding if communities are safe to gradually reopen, since the method would indicate prevalence. If a batch of pooled samples tests positive, the specimens within that batch could be tested individually to determine who is infected, then contact tracing would start. In pooled samples with no positive result, no individual processing would be needed, reducing the use of materials.
Back in business
Testing figures into most models predicting when local outbreaks will peak and when the economy can safely reopen.
For example, Morgan Stanley tied testing to its prediction of how COVID-19 is likely to peak, noting governors will probably be cautious about allowing people to gather in groups. “Importantly, investors should expect social distancing to wax and wane over the next year to contain ‘hot spots’ before a vaccine is widely available: While new cases will peak first, we do not believe governors are likely to allow any meaningful resumption until cumulative mortality peaks which lags new cases by ~20 days. This suggests nominal resumption could begin in June,” the report said.
“States will need to have appropriate public health infrastructure and testing capacity to allow for surveillance of new ‘hot spots’ which we also expect in June.”
The report recommends the CDC create a COVID-19 tracker similar to its influenza surveillance network. And it says serology testing must be “pervasive, which we also believe will take until June.”
If all those things happen, local leaders could start to loosen restrictions, but the report warns that if infection numbers rise, “we would expect significant social distancing measures to return.”
Protecting the herd
An effective vaccine will likely be available within a year or two. When enough people have recovered from the illness and enough who’ve avoided infection are vaccinated, the population could have “herd immunity,” Vento said.
Vento explained herd immunity by describing surrounding one who is susceptible with people who are not. “If you have a fairly high percentage of the population that is vaccinated or immune because of previous infection, then that virus cannot jump to that person,” he said.
With nowhere to go, a virus will die out in a community, he added.
What percentage must be immune depends on how contagious an illness is — and experts are still learning about this particular coronavirus, including what kind of immunity having survived infection provides.
Experts have suggested stopping COVID-19 would require at least 60% of a community to be vaccinated or immune. During a recent media briefing, Dr. Vineet Menachery of the University of Texas Medical Branch said most coronaviruses do not appear to confer lifelong immunity, but subsequent infections might be less severe.
The secondary attack rate is how many other people someone with a virus might infect. Measles is the best known and among the most contagious, with estimates as high as 18 people infected by each person who has it. Herd immunity math takes 1 divided by that attack rate and subtracts it from 1: So 1 minus 1/18 (the attack rate), which equals 17/18. That means about 95% of the population must be immune to have herd immunity to measles.
It’s believed COVID-19’s secondary attack rate is about 2.5, yielding the assessment that 60% or more of the population needs to be vaccinated or immune to provide adequate protection.
Some people would still become infected. Herd immunity is not perfect.
The attack rate can vary in different communities, Vento said.
Adequate and more sustained social distancing, as well as a phased and careful reopening of businesses could lower the secondary attack rate and reduce what’s required to provide adequate herd immunity so life can become more normal again, he said.