How to find hid­den in­fec­tions

Stan­ford and UC fast-track new tests

Times-Herald (Vallejo) - - FRONT PAGE - By Lisa Krieger and John Wool­foolk

The ma­jor­ity of peo­ple with coro­n­avirus feel just a lit­tle sick — and, untested, in­ad­ver­tently in­fect oth­ers and spread the po­ten­tially deadly dis­ease.

But this hid­den pop­u­la­tion could soon be re­vealed by new tests avail­able on-site at Stan­ford and UC San Fran­cisco. Striv­ing to meet the grow­ing de­mand for rapid an­swers. Stan­ford de­ployed its test on Wed­nes­day. UCSF’s test, which could de­liver re­sults even faster, will soon fol­low.

“This will give us an en­hanced ca­pa­bil­ity to test a wider swath of in­di­vid­u­als,” said UCSF’s Dr. Charles Chiu. “We re­ally have to an­swer whether or not there is on­go­ing com­mu­nity trans­mis­sion.”

On Tues­day, Santa Clara County health of­fi­cials an­nounced two ad­di­tional coro­n­avirus cases in which the source of in­fec­tion is un­clear. The lat­est an­nounce­ment brings to 11 the to­tal num­ber of cases in the county.

Wor­ried by the specter of com­mu­nity spread, the county is­sued new rec­om­men­da­tions for peo­ple at risk of the dis­ease. It urges res­i­dents over age 50 or those with med­i­cal con­di­tions to avoid large pub­lic gath­er­ings. such as movie screen­ings, bingo games, pa­rades, sport­ing events and con­certs where large num­bers of peo­ple are within arm’s length of one an­other. It does not in­clude typ­i­cal of­fice en­vi­ron­ments, gro­cery stores, or shop­ping cen­ters, where it is un­usual for large num­bers of peo­ple to be within arm’s length of one an­other.

A Berke­ley res­i­dent also has tested pos­i­tive, ac­cord­ing to city of­fi­cials there. This per­son has largely re­mained at home in a self­im­posed quar­an­tine since their re­turn from over­seas travel.

Con­tra Costa County con­firmed its first pos­i­tive case Tues­day in a pa­tient who had no travel his­tory or con­tact with a known sick per­son. Ac­cord­ing to Dan Ped­dy­cord, di­rec­tor of pub­lic health, and Ori Tzvieli, med­i­cal di­rec­tor for the pub­lic health divi­sion, the per­son is an adult male with un­der­ly­ing health con­di­tions who was ini­tially hos­pi­tal­ized with res­pi­ra­tory and flu-like symp­toms. The man is in crit­i­cal con­di­tion and iso­lated in an area hospital.

Glob­ally, 90,870 cases have now been re­ported in 72 coun­tries, with more than 3,000 deaths.

On Tues­day, the death toll in Wash­ing­ton state had risen to nine. And health au­thor­i­ties dis­cov­ered that two peo­ple who died last week were in­fected — sug­gest­ing that the virus had spread in the re­gion days ear­lier than they had known.

But those cases don’t re­flect the true scope of the epi­demic, ex­perts said. Like an ice­berg, many cases may not be seen, be­cause peo­ple don’t seek med­i­cal help.

Re­search in China shows that about 82 per­cent of the cases are mild, and that pro­por­tion may be an un­der­count, due to in­ad­e­quate test­ing. Young peo­ple, in par­tic­u­lar, stay healthy, with only 2.4% need­ing med­i­cal in­ter­ven­tion. Many are pre­sumed to carry the virus, but they suc­cess­fully fend off dis­ease.

Health of­fi­cials worry that younger peo­ple could un­wit­tingly in­fect el­ders, who are at great risk.

Ad­di­tion­ally, there is emerg­ing ev­i­dence that some pa­tients spread the virus dur­ing its in­cu­ba­tion pe­riod, which may last 14 days, then re­al­ize they are sick.

Right now, only a nar­row group of peo­ple are be­ing tested: those who are very sick and hos­pi­tal­ized, have re­cently trav­eled to China or South Korea or have been in con­tact with some­one con­firmed to have the virus.

The fed­eral Cen­ters for Dis­ease Con­trol and Pre­ven­tion has strict cri­te­ria for test­ing — and, un­til this week, the agency has been the only or­ga­ni­za­tion that was test­ing. The turn­around time for a re­sult from the CDC has been up to 72 hours. And the roll­out of the test was de­layed due to tech­ni­cal prob­lems.

As of Tues­day, 54 lo­cal and state pub­lic health labs, in­clud­ing Santa Clara and Alameda coun­ties, were able to con­duct tests, ac­cord­ing to the As­so­ci­a­tion of Pub­lic Health Labs. Each lab can test 100 pa­tients per day. When fully on­line, 100 pub­lic health labs will be ca­pa­ble of test­ing 10,000 pa­tients a day, it said. But the U.S. Food and Drug Ad­min­is­tra­tion pro­vided a higher num­ber, say­ing labs will be able to test up to 75,000 peo­ple.

“We’re test­ing ev­ery­body that we need to test,” Pres­i­dent Don­ald Trump in­sisted on Wed­nes­day dur­ing his first press con­fer­ence on the coro­n­avirus.

While the num­ber is in­creas­ing, tests still aren’t widely avail­able to the hos­pi­tals, clin­ics and pub­lic health labs across the coun­try that need them, say doc­tors.

It’s es­sen­tial to catch in­fec­tions quickly — on site — so sick peo­ple can be iso­lated be­fore they spread the virus to health­care work­ers, other pa­tients, fam­ily mem­bers and friends.

‘We could make a di­ag­no­sis at the front desk,” said Dr. Yvonne Mal­don­ado, in­fec­tious dis­ease spe­cial­ist and di­rec­tor of In­spec­tion Con­trol at Stan­ford Chil­dren’s Health.

Then the pa­tient could be quickly di­rected to a spe­cial iso­la­tion room, far from crowded wait­ing rooms, and treated by ex­perts in pro­tec­tive gear.

Un­til last week, aca­demic and com­mer­cial labs weren’t al­lowed to run the tests. But the FDA is­sued new rules late last week.

“That was a game changer,” said Chiu. “It per­mits lo­cal labs to do their own test­ing.”

The tests are pos­si­ble be­cause the full genome of the novel coro­n­avirus was pub­lished on Jan. 10, just weeks af­ter the dis­ease was first iden­ti­fied in Wuhan, China

The Stan­ford test, de­signed by the lab of Dr. Ben­jamin Pin­sky, med­i­cal di­rec­tor of the uni­ver­sity’s Clin­i­cal Vi­rol­ogy Lab­o­ra­tory, uses an ap­proach called qual­i­ta­tive real-time, re­verse tran­scrip­tase PCR. It de­tects the pres­ence of the virus’s E gene, which codes for the en­ve­lope that sur­rounds the vi­ral shell, as well as an­other gene.

Doc­tors take swabs from the back of the throat, above the soft palate that con­nects the nose to the mouth. Turn­around time for this test could be as fast as 6 hours. On Mon­day, it earned fed­eral ap­proval.

UC San Fran­cisco and the San Fran­cisco biotech com­pany Mam­moth Bio­sciences are tak­ing a dif­fer­ent ap­proach. They en­list CRISPR, the famed ge­need­it­ing tool, to de­tect snip­pets of the virus’s ge­netic ma­te­rial. They’re still work­ing to val­i­date the test’s ac­cu­racy and sen­si­tiv­ity, but aim to re­lease it within sev­eral weeks.

In prac­tice, the UCSF tool would work like a preg­nancy test, with re­sults in one to two hours. A strip of spe­cial pa­per would be dipped into a sam­ple con­tain­ing the CRISPR sys­tem. If the pa­tient’s sam­ple con­tains the virus’s ge­netic se­quence, it would change color.

Har­vard and sev­eral New York-based uni­ver­si­ties, as well as in­ter­na­tional groups in Europe and Hong Kong, also are work­ing on their own ver­sions of new tests.

“From a hos­pi­tals per­spec­tive, we would like to know — in ev­ery­one, where it’s plau­si­ble — whether or not COVID-19 is a pos­si­bil­ity,” said Paul Bid­dinger, Di­rec­tor of the Emer­gency Pre­pared­ness Re­search, Eval­u­a­tion and Prac­tice Program at Har­vard’s T. H. Chan School of Pub­lic Health.

“It all ties to test­ing,” he said.

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