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CIDRAP- CDC scientist challenges accuracy of Zika test

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  • CIDRAP- CDC scientist challenges accuracy of Zika test

    Source: http://www.cidrap.umn.edu/news-persp...racy-zika-test


    CDC scientist challenges accuracy of Zika test
    Filed Under:
    Zika
    Lisa Schnirring | News Editor | CIDRAP News
    | Sep 28, 2016

    Uncertainty about the reliability of tests used to detect acute Zika virus infections has been brewing at the US Centers for Disease Control and Prevention (CDC) since May, when one of its top scientists raised concerns, according to a report yesterday from the US Office of Special Counsel (OSC) to the White House on a CDC whistleblower investigation.
    The report, first disclosed by the Washington Post yesterday, concerns allegations from Robert Lanciotti, PhD, a microbiologist who is chief of the CDC's diagnostics and reference laboratory within its arbovirus disease branch at Fort Collins, Colo. Lanciotti asserts that the CDC's Trioplex test, which can test for Zika, chikungunya, and dengue virus, is nearly 40% less effective than the CDC's Singleplex test, used to detect only Zika.
    The OSC is an independent federal unit that handles whistleblower complaints and other employment issues.
    In other developments, the Senate today passed a government funding bill that includes $1.1 billion in Zika funding, with the measure set for a House of Representatives vote, and Miami officials?under pressure?revealed where Zika-positive mosquitoes were trapped.
    Scientist, CDC disagree on test sensitivity

    The US Food and Drug Administration (FDA) issued an Emergency Use Authorization (EUA) for the CDC's Trioplex reverse-transcriptase polymerase chain reaction (RT-PCR) test in March for use in differentiating the three viruses in blood, cerebrospinal fluid, urine, and amniotic fluid for patients meeting the CDC's Zika virus clinical criteria.
    The EUA stipulates that negative Trioplex RT-PCR results do not rule out the three infections and shouldn't form the sole basis of patient management decisions. The FDA also says negative results should be combined with clinical observations, patient history, and epidemiologic information.
    Lanciotti is known for his earlier work to develop molecular tests for mosquito-borne disease and his work with West Nile virus. His own tests had shown that the Trioplex test missed 39% of Zika infections that were positive on the Singleplex test. The CDC, however, countered that scientists at a CDC lab in Puerto Rico found no sensitivity difference between the two tests.
    The OSC said it referred Lanciotti's concerns to the Department of Health and Human Services (HHS)?the CDC's parent agency?for investigation on Jul 1, and a resulting CDC probe wasn't able to reach a statistically valid conclusion about the relative performance of the tests.
    In addition, Lanciotti also raised concerns that the CDC's Emergency Operations Center was withholding information about the sensitivity differences from public health laboratories. The CDC's investigation found that the decision was reasonable in light of the inconclusive data. In comments on the CDC's investigation, Lanciotti disagreed, writing that "there was clearly enough data to warrant a 'pause' in the recommendation of the Trioplex" until definitive results from a head-to-head comparison were known.
    An independent research institution with the most accurate method to evaluate clinical sensitivity also found a lower sensitivity for the Trioplex test, Lanciotti said when he weighed in on the CDC's investigation.
    Before disclosing his concerns to the OSC, Lanciotti raised the issue internally and an in e-mail to state public health officials in April. In May the CDC reassigned him to a nonsupervisory position in his lab, which prompted him to file a whistleblower claim that his diminished duties amounted to retaliation for his disclosures. After an investigation, the OSC secured an agreement from the CDC to reinstate Lanciotti as lab chief.
    Carolyn Lerner, special counsel with the OSC, said in a statement on the report, "As the agency contemplates additional improvements or changes to the Zika testing protocol, I encourage CDC to review Dr Lanciotti?s comments, respond to each of his concerns, and utilize his expertise as the agency works to ensure it is implementing the most effective testing methods in response to this public health emergency."
    She also said, "I also encourage the CDC to promote scientific debate within its labs. Whistleblowers should be encouraged to speak out on matters of public concern."
    In a statement released to the Washington Post yesterday, the CDC said it conducted a thorough independent investigation and found that the allegations aren't backed up by evidence. It said it is committed to arming public health officials with the best tools to fight the virus and that it continues to strengthen the Trioplex test, which will include an instructions update to boost its performance. The agency added that it needs simpler, quicker tests and that research to develop them is critical and needs additional funding from Congress.
    Senate passes Zika budget bill

    The Senate today approved a bill to temporarily fund the government though Dec 9, which includes $1.1 billion to support Zika virus response, USA Today reported.
    According to the report, Senate members agreed on removing two controversial riders that were added to earlier versions of the Zika funding bill: one that barred support from Planned Parenthood in Puerto Rico, which is battling a large outbreak, and one that relaxed laws on the use of pesticides in bodies of water.
    Lawmakers face a Sep 30 deadline to fund the government for the start of the 2017 fiscal year, which begins Oct 1. Members of Congress are also eager to break for political campaigns and won't be back in session again until after the November elections.
    The White House today signaled that it supports the Senate's budget bill, called a continuing resolution, and the House of Representatives is expected to vote on it later today.
    Florida trap locations revealed; local cases climb

    Officials from Miami-Dade County today revealed the Miami Beach locations of traps that collected mosquitoes carrying Zika virus, prompted by a lawsuit from the Miami Herald, which has been pushing for more outbreak investigation details. Officials had already disclosed that one of the five sites is Miami Beach Botanical Garden.
    Two of the remaining sites are apartment buildings, one 12-unit building and one with 8 units. Another is near two high schools.
    The state's Department of Agriculture and Consumer Services announced the first three positive traps on Sep 1 and announced the two others on Sep 9 and Sep 16. Follow-up tests on mosquito traps from all five locations were negative.
    According to the Herald, Miami-Dade County and the Florida Department of Health (Florida Health) had opposed the newspaper's public records request on the ground that the records were exempt because they were part of an epidemiologic investigation. Yesterday, Miami-Dade Mayor Carlos Gimenez sent a letter to a state official saying county officials would release the locations unless otherwise instructed by Florida Health. State officials said the county was free to reveal trap locations to the public.
    Meanwhile, Florida Health is reporting 4 new local Zika cases, according to an update yesterday. Authorities are investigating where exposure occurred for all of them. The new cases bring Florida's number of local infections to 109.
    Also, Florida Health reported 1 more out-of-state resident who contracted Zika virus in Miami-Dade County, lifting that total to 11.
    Microcephaly, vector control, and animal surveillance

    • In other news, Thailand has ruled out Zika virus in two of four microcephaly cases it is investigating, Reuters reported today. Health officials are still investigating two other possible Zika-linked cases of the birth defect. Of the four cases being assessed, three involve babies and one involves a 36-week-old fetus. Experts are closely watching developments in Southeast Asia to see if the Asian strain there, which appears to be related to earlier strains from the region and not the Americas, is capable of causing microcephaly.
    • The CDC yesterday announced that it has awarded the Puerto Rico Science, Technology, and Research Trust $13 million to establish the territory's first vector control unit (VCU), which will oversee and implement comprehensive mosquito control activities to help prevent and curb the spread of mosquito-borne diseases like Zika. Once established, the VCU will develop an integrated surveillance and control plan and carry out mosquito control steps throughout Puerto Rico.
    • Researchers who examined the blood of 239 wild African primates found evidence of earlier Zika infection, a research team based at the University of Wisconsin, Madison, reported in bioRxiv, a preprint server for science publications. The looked at four wild primate populations: baboons in Tanzania and Zambia and African green monkeys in South Africa and Gambia. Their testing found Zika antibodies only in Tanzanian yellow baboons and Gambian African green monkeys, which the researchers said suggests Zika infections in non-human primates isn't limited to a particular host species, but may be affected by other factors such as geography. They noted that the Zika antibodies were more common in primates living in the northern parts of sub-Saharan Africa.

    See also:
    Sep 27 OSC statement
    Sep 27 Washington Post story
    Sep 28 USA Today story
    Sep 28 Miami Herald story
    Sep 27 Florida Health daily Zika update




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