Clinic regrets claim of new Zika infections

Test results on 6 pregnant patients not conclusive to specific diagnosis

Legacy Community Health walks back its claim that six pregnant Houstonarea women were infected with Zika, saying instead they were exposed to a flavivirus, a family that includes Zika, West Nile and other illnesses.

The southeast Texas health system that reported on Thursday the first cases of the Zika virus in Harris County in 2017, six then-pregnant women, has backed off the claim.

Legacy Community Health, the network of clinics where the women had their blood drawn, announced Friday that an in-depth review since conducted determined only that the expectant mothers were infected with a virus from the family that includes not just Zika but West Nile, dengue and yellow fever, among others.

“We can only confirm the individuals were exposed to a flavivirus, which can include Zika as well as other viruses,” Dr. Ann Barnes, Legacy’s chief medical officer, said in a statement. “The laboratory results do not provide a conclusive diagnosis that the women became infected specifically with Zika virus. Legacy regrets the error.”

All of the women delivered their babies, none with the abnormally small head that characterizes the worst form of Zika when the virus is passed on by the mother. The women, who contracted the mosquito-borne virus south of the border, were tested because of their risky travel histories, not because they were experiencing Zika symptoms.

Legacy officials did not respond to follow-up inquiries Friday.

A Houston health department spokesman said the mistake involved a misinterpretation of the results the Centers for Disease Control sent Legacy in late May. Flaviviruses can be hard to differentiate because, structurally, they look very similar.

Both the Houston and Harris County health departments contacted Legacy on Thursday to look closer at the test results because the report of new cases conflicted with their Zika records.

Legacy’s report had heightened concern about the coming Zika season in the U.S. Gulf Coast, which experts believes appears less threatening than last year’s. Zika activity is down in most of South America, the Caribbean and Central America, the areas that imported most of the U.S. cases last year.

But Houston Zika expert Dr. Peter Hotez suggested Friday that Legacy’s six cases may still have been Zika.

“The flaviviruses circulating most commonly from November to spring in Mexico and Central America are dengue fever and Zika,” said Hotez, founding dean of the National School of Tropical Medicine at Baylor College of Medicine and Texas Children’s Hospital. “I’d suspect dengue first because its numbers are the highest, but if they were infected with it, they’d likely be sick. That they weren’t suggests Zika.”

Zika, which has spread to more than 80 countries since emerging as a global threat a decade ago, has been linked to microcephaly, in which the infected mother’s baby is born with an abnormally small head and brain.

The condition can result in developmental delays, intellectual disability and hearing, vision and feeding problems.