Is a perfect storm of Zika virus conditions coming to the Gulf Coast?

In the wake of the CDC’s revelation that Zika virus causes microcephaly in infants, doctors are grappling with the thorny issue of whether they should recommend that women in high-risk areas avoid getting pregnant this summer. Hari Sreenivasan talks to Dr. Peter Hotez of Baylor College for more on how medical experts are confronting the prospect of Zika in the U.S.

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    Finally tonight: worries over a potential Zika outbreak in the U.S., and who may suffer a bigger impact.

    Public health officials have been increasingly concerned about the virus spreading via mosquitoes this summer. One report even suggested government officials were split over whether to advise women to avoid pregnancy in areas where Zika is circulating.

    In an op-ed titled "Zika Is Coming," Dr. Peter Hotez focused on some of these questions and what it might mean in some cities in the southern parts of the country. He's the dean of the National School of Tropical Medicine at Baylor College of Medicine and a pediatrician and microbiologist at Texas Children's Hospital. I interviewed him from our New York studios.

    I want to read you the first sentence of the op-ed you wrote in The New York Times recently. It said: "If I were a pregnant woman living on the Gulf Coast or in Florida in an impoverished neighborhood and city like Houston, New Orleans, Miami, Biloxi, Mississippi, or Mobile, Alabama, I would be nervous right now."


  • DR. PETER HOTEZ, Texas Children’s Hospital:

    Well, the reason I made that statement, Hari, was because what we know, where this terrible birth defect, microcephaly, is happening.

    It happens when pregnant women are bitten by the Aedes mosquitoes. So, the first requirement is, it has to be a part of the world where we have the Aedes mosquito. And, also, the other component that not many people appropriate is both crowding and poverty.

    And the reason why poverty is so important is because women who live in poverty have increased exposure to mosquitoes because of absent — or broken window screens, collected garbage, environmental degradation near the home that breeds mosquitoes.

    And so what you have on the Gulf Coast of the U.S. is the perfect storm of all three factors, the Aedes aegypti mosquito, the extreme poverty and crowding, that you would find in Northeastern Brazil, which is the epicenter of this epidemic or what we have seen moving into Colombia.

    So, for all the reasons we're seeing microcephaly cases appear in Brazil and Colombia, I believe we're going to see on the Gulf Coast, especially as we move into the warmer months, when our mosquito numbers start to rise.

    So we're already finding Aedes aegypti mosquitoes on the Gulf Coast, including here in Houston. But I'm very worried that as we go into the warmer months, those mosquito numbers are going to incline, with it, the poorer neighborhoods on Gulf Coast cities, such as Houston, New Orleans, others, are really going to be affected by Zika.


    So, what's that timeline of progression that you see? Not all mosquitoes have Zika. It will take some time for some of them to get Zika, and then some of them to bite people, some of those people to have symptoms, some of those symptoms to be severe.


    Well, arboviruses, viruses transmitted by mosquitoes are not new to the Gulf Coast. We have experienced a number of epidemics of arboviral infections.

    For instance, in 2003, Houston experienced an epidemic dengue fever caused by the same Aedes aegypti mosquito. And what we found was, those numbers started to rise in May and into June, and with it, we then started seeing a dengue outbreak back in 2003.

    So, I would expect, if Zika is going to strike the Gulf Coast, it would go by a similar playbook. Beginning in May, June, into the summer months is when we could see start seeing Zika transmission on the Gulf Coast.


    Should local health officials be advising women to delay pregnancy?


    Well, it depends really where we're talking about.

    So, right now, Zika is rampaging through Puerto Rico. According to the CDC, maybe half or even more of the island is going to be infected by the Zika virus within the coming weeks. And this is how Zika goes. It affects the immunologically naive population and sweeps through it very quickly over a period of months.

    We saw this in Micronesia and French Polynesia and Brazil and now in Puerto Rico. So, during that time period, I'm of the opinion, if it's possible, to try and delay pregnancy during that time when large numbers of women are getting exposed to the Zika virus. Having said that, it's easier said than done.

    We have to remember the problem of advising women to delay pregnancy, who is Zika affecting? It's affecting predominantly women who live in poverty, not exclusively, but that's disproportionately affecting women who are impoverished.

    So it's a very tough call. Right now, we do not have Zika virus transmission on the Gulf Coast, so I wouldn't make that recommendation, but it's something that we're going to have to revisit as we get into the warmer months.


    What about the idea of false-positive cases that have happened in Brazil, and that so many Zika infections don't even lead to the equivalent of a cold or mild fever?


    Well, we're starting to change our opinion on the virus.

    You know, we used to say that 80 percent of cases are without symptoms, asymptomatic. That's probably an overestimate. The real question that we would like to know is, if you're a pregnant woman and you become pregnant with the Zika virus, what's the likelihood you're going to give birth to a baby with microcephaly or other terrible congenital birth defects?

    So, the stakes are very high. I think, for now, we have to assume that if a mother is infected with the Zika virus, the likelihood that she will give rise to a baby with micro — that she will give birth to a baby with microcephaly is significant, and we have to plan accordingly.


    Dr. Peter Hotez from the Texas Children's Hospital and Baylor College of Medicine, thanks so much.


    Thanks for having me.

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