Lab di­luted so­lu­tion used to de­tect Zika

Er­ror ren­dered useless D.C.’s test­ing for the virus

The Washington Post Sunday - - FRONT PAGE - BY AARON C. DAVIS

When An­thony Tran took over the District’s pub­lic health lab late last year, he had a feel­ing some­thing was wrong with its test­ing for the Zika virus. He had just come from the pub­lic health lab in New York City, where tech­ni­cians had been find­ing mark­ers for Zika in the blood of ar­riv­ing trav­el­ers al­most ev­ery day. In the smaller, but still in­ter­na­tional, city of Wash­ing­ton, the same test was neg­a­tive — ev­ery time.

Soon, U.S. health of­fi­cials joined in Tran’s con­cern: Sam­ples sup­plied by the fed­eral gov­ern­ment of the fright­en­ing, mos­quito-borne virus that were tested in the lab as a con­trol were ap­pear­ing as if they con­tained no virus.

“I knew then that some­thing was tremen­dously wrong,” Tran said late last week in an in­ter­view. He halted test­ing, and with help from an­a­lysts at the Cen­ters for Dis­ease Con­trol and Pre­ven­tion, traced the prob­lem to a mis­take that any high school chem­istry stu­dent

could un­der­stand.

There were two types of so­lu­tion the District could have pur­chased to con­duct a phase of the test. One bot­tle came marked with a “D,” for di­luted, and the other with a “U”, for undi­luted. D.C. lab work­ers had pur­chased the di­luted ver­sion, Tran said, and then mis­tak­enly wa­tered it down as if it was the more con­cen­trated one, weak­en­ing the ability to de­tect for Zika.

For a pub­lic health lab to com­mit such an er­ror once would be an em­bar­rass­ment in the high­stakes test­ing of Zika, which has po­ten­tially dev­as­tat­ing con­se­quences for preg­nant women, sci­en­tists and fed­eral health of­fi­cials say. That the District lab — which is also a first line of de­fense in screen­ing bioter­ror­ism threats — re­peated the mis­take daily, and without any­one catch­ing it for more than six months, amounts to a more sys­temic and wor­ri­some fail­ure, ex­perts said.

In­ter­views and pub­lic doc­u­ments show that the de­ba­cle un­folded over a pe­riod of months last year in which the District lab was in a state of tur­moil — un­der­staffed, lack­ing per­ma­nent lead­er­ship, spread thin on com­pet­ing projects, and re­ly­ing on new em­ploy­ees to test for the emerg­ing pub­lic health threat in Zika.

“A rel­a­tively in­ex­pe­ri­enced staff and a lack of lead­er­ship — that’s a bad com­bi­na­tion,” said Kelly Wrob­lewski, di­rec­tor of in­fec­tious dis­eases for the As­so­ci­a­tion of Pub­lic Health Lab­o­ra­to­ries, which works to safe­guard the in­tegrity of pub­lic health labs na­tion­wide. “The pos­i­tive here is that the lab does have new lead­er­ship and he caught the er­ror quickly, even though the sit­u­a­tion is al­ready really, very un­for­tu­nate.”

Since D.C. of­fi­cials an­nounced the er­ror on Feb. 9, pub­lic health of­fi­cials in a net­work of nearly 50 labs study­ing Zika have ques­tioned how it could have gone so wrong. It was the only ju­ris­dic­tion in the coun­try to have mis­han­dled the test­ing.

In the District, the mishap has shaken pub­lic con­fi­dence in Zika test­ing and, at­tor­neys say, could re­sult in mil­lions of dol­lars in le­gal claims. And all of that may pale in com­par­i­son to the ef­fects that the botched tests may have on a hand­ful of D.C. fam­i­lies.

At least nine preg­nant women in the na­tion’s cap­i­tal were caught in the faulty test­ing be­tween July and De­cem­ber of last year, D.C. of­fi­cials said Thurs­day. The women were told they did not have Zika when in fact new test­ing by a CDC lab in Colorado shows that the women did have an­ti­bod­ies that could sig­nal the pres­ence of the virus. Fol­low-up tests on eight have been in­con­clu­sive, and one has been con­firmed as hav­ing a Zika in­fec­tion.

District of­fi­cials say they do not know how far along any of the women were in their preg­nan­cies when they were wrongly told they were healthy. The District also does not know whether any of the women have since given birth.

Zika is pri­mar­ily trans­mit­ted through the bite of an in­fected mos­quito, but it can also be passed through sex, even if the in­fected per­son shows no symp­toms.

Pub­lic health of­fi­cials say they have re­layed the new test results to the women’s health-care providers, and they are gird­ing for the num­ber of new Zika pa­tients to rise as retest­ing is com­pleted for the fi­nal third of the 300 preg­nant women the District says were in­ac­cu­rately tested.

Ac­cord­ing to a study in De­cem- ber, about 6 per­cent of preg­nant women be­lieved to be in­fected with Zika in the United States had a baby or fe­tus with at least one birth de­fect re­lated to the vi­ral in­fec­tion last year. Most suf­fered from se­vere mi­cro­cephaly, char­ac­ter­ized by abnormally small head size and, of­ten, an un­der­de­vel­oped brain.

But ba­bies in­fected with Zika are not al­ways ob­vi­ous. Some prob­lems stem­ming from in­fec­tion may not show up un­til a year af­ter birth or longer and can in­clude hear­ing loss, ir­ri­tabil­ity, dif­fi­culty swal­low­ing, and cog­ni­tive, sen­sory and mo­tor-skill dif­fi­cul­ties.

That means the fall­out in the District may not be felt for some time.

‘A mad scram­ble’

Tucked away in the District’s new glass-and-steel foren­sic sci­ences build­ing, a cou­ple of blocks south of the Na­tional Air and Space Mu­seum, are a group of sci­en­tists who toil away on vi­tally im­por­tant work.

At inau­gu­ra­tion time, they test the food served at high-dol­lar balls for food-borne ill­nesses and con­tam­i­na­tion. When a sus­pi­cious, white pow­der is found in the District, the lab is one of the first to test the sub­stances for bi­o­log­i­cal weapons. And on more mun­dane days, the staff of the Pub­lic Health Lab­o­ra­tory Divi­sion tests wa­ter pol­lu­tion in the Po­tomac and helps to iden­tify in­fluenza strains that should be in­cluded in the next year’s vac­cines.

As a divi­sion of the District’s Foren­sic Sci­ences Department, the lab was rarely in the news.

By com­par­i­son, the lab’s sis­ter divi­sion, the crime lab, had to halt DNA test­ing in 2015, af­ter ques­tions sur­faced about the ac­cu­racy of its work.

The scan­dal forced out the department’s for­mer di­rec­tor and D.C. Mayor Muriel E. Bowser (D) brought in Jenifer Smith, a for­mer FBI forensics expert, to clean house and re­store the lab’s rep­u­ta­tion.

Ac­cord­ing to two of­fi­cials fa­mil­iar with Smith’s re­build­ing plan, as well as pub­lic bud­get doc­u­ments from the agency, Smith’s top pri­or­ity early last year was restart­ing DNA test­ing at the crime lab.

In the year be­fore it con­fronted Zika, the pub­lic health lab was shed­ding its most ex­pe­ri­enced staff — for a va­ri­ety of rea­sons.

For­mer di­rec­tor Al­pha Diallo, a na­tive of Guinea, left to fight Ebola in Africa. The lab’s head of virol­ogy, Anicet Da­hourou, and its head of mi­cro­bi­ol­ogy, Mor­ris Blay­lock, also re­signed and took jobs with the CDC in At­lanta.

In March 2016, with Zika as a loom­ing threat, three of the lab’s six qual­ity-as­sur­ance jobs were va­cant.

Mau­rice Knuck­les, who had di­rected the of­fice a decade ear­lier, was brought back from semire­tire­ment by Smith to run things on an in­terim ba­sis, of­fi­cials said.

Blay­lock, reached in At­lanta, said pre­par­ing for Zika in the early months of last year with a thin staff was “a mad scram­ble.”

The District wanted to join dozens of states that were ap­ply­ing to the CDC for the author­ity to con­duct their own Zika tests in­stead of ship­ping them off to the fed­eral agency. To ap­ply, the lab was sent a panel of blind tests by the CDC and had to repli­cate pos­i­tive and neg­a­tive results achieved at a fed­eral lab.

The D.C. health lab suc­cess­fully did so and got per­mis­sion in late May to be­gin its own Zika test­ing pro­gram, Tran said.

Smith said the lab hired four peo­ple to con­duct the tests and trained them for weeks be­fore Zika test­ing was launched on July 14.

In an in­ter­view, Smith and Tran said it was un­clear whether the lab em­ploy­ees had used the ap­pro­pri­ate di­lu­tion in the spring when the lab passed the CDC test.

But Tran said that it is now clear that by July, work­ers had be­gun the lab’s Zika test­ing with an over-di­luted so­lu­tion.

It was not caught ear­lier, Tran said, be­cause even with a weak­ened so­lu­tion, daily con­trol tests still showed pos­i­tive results, at least, un­til a fi­nal batch was mixed late last year.

Blay­lock said the loss of the lab’s virol­ogy di­rec­tor was a ma­jor gap, and any sus­tained cam­paign of virus test­ing would have ex­posed weak­nesses in the team’s staffing.

“We could deal with an emer­gency re­sponse, we could man­age it for a short time, but any­thing long-term, it was go­ing to wear down that team be­cause it was so short-staffed,” he said. “I know they were try­ing to get per­son­nel on board; I do know that was the pri­mary chal­lenge.”

Smith dis­missed the idea that the botched tests were the re­sult of a newly hired staff or lack of sea­soned leaders in key po­si­tions. “This is not an is­sue of staffing,” she said.

“The pos­i­tive here is that the lab does have new lead­er­ship and he caught the er­ror quickly, even though the sit­u­a­tion is al­ready really, very un­for­tu­nate.” Kelly Wrob­lewski, di­rec­tor of in­fec­tious dis­eases at the As­so­ci­a­tion of Pub­lic Health Lab­o­ra­to­ries

‘Some­thing’s wrong’

The faulty so­lu­tion wasn’t the fail­ure point that Tran no­ticed in the District’s Zika test­ing pro­ce­dures when he joined the lab late last fall.

Con­cerned about the high num­ber of neg­a­tive results, Tran be­gan dou­ble-check­ing the team’s math and found an er­ror, he said. Lab work­ers had fum­bled a for­mula to cal­cu­late test results, skew­ing some in­con­clu­sive ones to­ward neg­a­tive results.

“I started to in­ves­ti­gate, and the first thing I found was a really, a quite ba­sic arith­metic er­ror,” he said.

That dis­cov­ery led Tran to stop the test­ing and re­cal­cu­late the score for the tests done since July.

None of the re­cal­cu­la­tions re­sulted in a shift to a clearly pos­i­tive re­sult, he said. Tran was pre­pared to re­sume test­ing in the lab when a new prob­lem de­vel­oped with the daily con­trol tests: “Now, we were get­ting no re­ac­tion through the plates, and I said, ‘Some­thing’s wrong . . . . We need to do a deep dig and fig­ure out what’s wrong.’ ”

Tran said he knew the lab would at­tract in­tense scru­tiny over the mis­take but never hes­i­tated to go pub­lic.

“I knew what was go­ing to be hap­pen­ing, but there was no other de­ci­sion for me to make,” he said. “You need to give the best care, be­cause there’s no cure for this.” Staff writer Lena H. Sun and re­searcher Jen­nifer Jenk­ins contributed to this re­port.

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