More Testing Needed For The Gradual Reopening Of Nevada

Apr 24, 2020

Coverage of novel coronavirus is supported by the Mick Hitchcock, Ph.D., Project for Visualizing Science, a science reporting project from the Reynolds School of Journalism.

Editor's Note: This story aired before Washoe County Regional Information Center held a virtual press conference on April 24th. Washoe County Health District Kevin Dick provided new information about testing in the community. He says the state has requested the county to target 1,000 COVID-19 tests per day beginning Monday, April 27th. Dick says the county does not have the capacity to reach that target yet since there is currently still a shortage of testing supplies and equipment to process that amount. The district is currently working with the Nevada State Public Health Laboratory and other agencies to increase capacity, and will provide more information on the process next week. 

When will the state’s shutdown be lifted is on the minds of many Nevadans. Governor Steve Sisolak held a press conference earlier this week to update residents.

“Due to the criteria that was developed by the state team and in accordance with White House guidance,” Sisolak said, “as of right now, I can not give you a firm date as to whether we will meet all of this criteria to begin phase one reopening plans.”

As KUNR’s Anh Gray reports, those criteria include meeting health benchmarks, which will require more testing.

Federal guidance advises that a gradual reopen should be based on a trend of decreasing COVID-19 cases and hospitalization rates. Governor Sisolak has made it abundantly clear that he’s consulting with medical and public health advisors on when it would be safe to gradually ease the shutdown.

So far, Nevada has performed more than 42,000 tests statewide since the beginning of March. Sisolak says COVID-19 testing data could be used to make decisions about easing restrictions.

“If we see an uptick in infection, if there’s an uptick in hospitalizations or ICU hospitalizations, we're going to have to look at, kind of ratcheting it back a little bit,” Sisolak said. “Hopefully, we're going to adopt a very gradual approach and we won't see that, and we'll be able to have some control as we move forward.”

The governor held another press conference last week. Dr. Mark Pandori who heads up the Nevada State Public Health Laboratory spoke at the event. He said that testing can help determine if the number of COVID-19 cases is declining, or in other words, whether that curve is flattening.

“If we wanted to come out of this and slide down the other half of this curve, you might think, 'Well, gee, testing might become less important,' ” Pandori said. “It becomes more important, and so we have to press on the gas pedal and get even more testing done.”

A key reason to test a patient is the medical function: to treat a sick person. Aside from that, Pandori said that testing is also critical for public health surveillance, which is needed to contain the spread of disease.

“This is about gathering intelligence," Pandori explained. “This is about finding out where the enemy is, how much of it, and finding out that number for two reasons: how much risk is there out there as we start to come out of this and try to reenter normalcy, but also to ask, ‘Hey, when the smoke clears, how many people were infected and are infected?' because we still don't know that denominator.’”

Shortages of testing supplies are an issue nationwide, and in Nevada, during the pandemic, but according to Pandori, that’s going to change over the coming weeks. More clinicians, hospitals, public health labs and larger private labs statewide will be getting supplies and equipment to ramp up testing capabilities.

At a virtual press conference earlier this week, Washoe County Health District Officer Kevin Dick said that he’s working toward the goal of increasing testing capacity. “We're making plans to be able to expand our drive-through testing, to have a more frequent schedule, perhaps daily, instead of the four days a week,” Dick said, “and to add additional personnel and stations for collecting the tests so that we can have more people go through that process for the specimen collection.”

A health care worker holds a COVID-19 specimen collection kit at a Washoe County Health District drive-through testing site.
Credit Bree Zender

Dick says he’s coordinating testing capacity with state health officials, who estimate there should be about 4,000 tests per day statewide to adequately mitigate COVID-19. For Washoe’s size, Dick says about 600 tests a day are necessary.

“But that also entails all of the personnel that we need to have then to be doing the scheduling, to be preparing all the paperwork and labels, et cetera, for, doing the testing, notifying people of the results, doing the case investigations and case contact tracking,” Dick explained.

Data from testing for COVID-19 is crucial, but health officials also want to understand how much immunity is already out there. Dr. Mark Pandori says that another type of test, the antibody test, provides the state with the information to plan the response.

“As we're coming out of this and as the smoke is clearing,” Pandori said, “it will help public health immensely understand who really was infected with this virus because we still don't know.”

The antibody test is a blood test. It can detect if a person has developed the antibodies, which is an immune response when they come in contact with the virus. Widespread antibody testing can help officials determine how much of the population has already been exposed, which can also help determine how much herd immunity is in the population. In the absence of a vaccine to protect against COVID-19, more herd immunity is needed to slow the spread of infection and protect the population.

Pandori warns that it’s unclear at this time whether a positive result from an antibody test can determine if someone might be immune to a future infection, and antibody testing still has limitations.

Dr. David AuCoin agrees. He’s an associate professor and chair of the department of microbiology and immunology with the University of Nevada, Reno School of Medicine.

“Those tests, a lot of times, aren't perfect, so they may yield a small percentage of false positives,” AuCoin said. “For example, you know, where someone may think they have antibodies and they actually don't.”

A false positive test, which shows that someone has antibodies to the virus when they actually don’t, could lead to a false sense of security. And for some, especially health care workers, that could be risky.

“If you're testing to see if they have specific antibodies that bind, specifically, to this virus, you want to make sure that that test is very accurate before you send them back into work,” AuCoin explained. “As a nurse or an ER doctor or a physician's assistant or something like that, they want to have the confidence that, you know, potentially they'll be protected.”

Aucoin says that even when an antibody test might yield a small percentage of false positives, those numbers add up when tests are used to make decisions affecting the population.

“So, even if that percentage could be very small, it could be one or 2%, of the tests that are run may yield a false positive, which actually is pretty good,” Aucoin said. “But when you're talking about testing entire communities [of] 10,000 [or] 100,000 people, the amount of false positives will go up. And so, to get those antibody tests as accurate as possible, I think, is critically important.”

The state public health laboratory is currently evaluating the accuracy of the antibody test prior to its widespread use statewide.

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