Zika update: Scientists still learning about ‘strange’ virus

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    Health workers spray insecticide to combat the Aedes aegypti mosquito that transmits the Zika virus in Rio de Janeiro

    Health workers spray insecticide to combat the Aedes aegypti mosquito that transmits the Zika virus in Rio de Janeiro

    Zika is not a new virus. It was first identified in the forests of Uganda in 1947, but it was only in recent months, in light of a growing epidemic first identified in Brazil, that it’s really been under close scrutiny.

    “We’re learning more and more each week,” said Scott Weaver, a virologist at the University of Texas Medical Branch.

    Weaver has been studying Zika cycles in Africa for a long time. Now, he’s on the forefront of efforts to take on the virus’ latest turn. The Pulse’s Maiken Scott recently caught up with him.

    Interview highlights:

    Zika outbreaks have been small and sporadic, but that’s a big contrast what appears to be developing in Latin America and the Caribbean.

    “People are very worried in Brazil,” said Weaver, who has been teaming up with doctors there to better understand how Zika is spread. “I don’t think anyone’s very optimistic that mosquito control is going to be the solution to controlling this outbreak.”

    For most people, Zika produces few discernable symptoms. But for some pregnant women, the virus has been associated with microcephaly, or fetal anomalies.

    Weaver says the virus typically stays in a person’s system for about two weeks, but there are two key exceptions: “One is that when men become infected, the presence of viral material has been detected in semen more than two months later. Weaver says we don’t know if that virus is still capable of affecting male or female partner sexually.”

    The other, is the virus appears to have a prolonged life in the blood stream of a pregnant woman who develops a fetal infection.

    “That can last for many weeks and even a few months,” Weaver said.

    For that reason, Weaver said it’s important to educate pregnant woman about postponing travel to affected areas of Latin America and the Caribbean.

    He says compared to other mosquito-borne viruses, Zika is especially strange.

    “This is the only mosquito-born virus that we have learned can be sexually transmitted,” he said. “And then the microcephaly—the fetal infection with these bad outcomes where the brain doesn’t develop normally—this is the first human mosquito born virus known to cause this.”

    So should people in the U.S. be worried?

    The U.S. does have mosquitoes that could carry the virus and has also documented about 300 cases of people becoming infected with Zika abroad and then returning, but Weaver says there’s nothing to panic about.

    “What I don’t think we need to be concerned about is millions of people getting the Zika virus infection here,” he said. “Because we simply don’t have the same degree of contact with mosquitoes, thanks to our air conditioners and screening on our windows in the U.S.”

    As for vaccine development, Weaver says preclinical testing is moving along. The NIH is hoping to begin a clinical trial of some of the first vaccine candidates later this year.

    “But getting a vaccine the whole way through the regulatory process is probably going to take a few years,” he said.

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