On Feb. 1, the World Health Organization (WHO) convened the first meeting of the International Health Regulations Emergency Committee on Zika virus, in which they assessed the severity of the global health risks that are associated with the “explosive spread” of the Zika virus throughout Latin America and the Caribbean.
Due to the connection between Zika and microcephaly-based neurological disorders in babies, the WHO declared that the Zika virus constitutes a Public Health Emergency of International Concern.
To help understand what this designation means and the implications it may have on the upcoming elections, global health security, and couples trying to get pregnant, Dr. Peter Hotez, M.D., Ph.D., dean of the Baylor College of Medicine National School of Tropical Medicine, spoke with BioNews correspondent Kara Elam before flying to the Middle East, where he represents the U.S. as part of President Barack Obama’s U.S. Science Envoy to the Middle East.
Dr. Hotez, over the last few weeks it has become clear that there is a lot about the Zika virus that we don’t know or understand. Could you share with our readers what we do actually know for certain about the Zika virus?
We know it is an arbovirus, a virus transmitted by mosquitoes. It causes febrile illness, associated with rash and headache and pain behind the eyes, retro-orbital pain; there may be some joint symptoms like all the other arboviruses have. And the big unusual feature is its apparent ability to cause congenital infection leading to horrific birth defects. We know this from isolation of the virus from babies with microcephaly, amniotic fluid of mothers who, by ultrasound, are shown to have a fetus with microcephaly, and from the placentas from deliveries of babies with microcephaly.
The problem is, you don’t always have isolated viruses from the babies. We don’t have all our i’s dotted and t’s crossed. It is going to be very important to know and to really pin down the association. It also means we have to proceed from a public health point of view as though that is the way it is, that it really is associated with vertical transmission [mother to baby in womb], and congenital infection, because to not do anything and just wait for babies to show up in the Caribbean and elsewhere this virus is marching into, and for babies to show up in obstetrical wards and labor and delivery suites with microcephaly, is not acceptable — we have to intervene now.
So that is one of the things we know. We also know this virus is spreading very rapidly. It is one of the fastest-moving viruses I’ve ever seen. It has gone from Brazil in the middle of fall last year to Columbia, and into Central America and southern Mexico, and then moving into the Caribbean. By the end of this month it will be all over the Caribbean.
With the length of your career, that is saying quite a lot.
Yes. I mean chikungunya also spread very quickly, so I think one of the unknowns is why are these arbovirus infections spreading so rapidly? I think is a big unknown.
That relates to my second question. During the presentation as to why the WHO declared Zika to be a Public Health Emergency, Dr. Chan said that the virus has gone from “a mild threat to alarming proportions in such a limited time frame.” She also noted that increased global travel and rising global temperatures played a role in this rapid spread. Can you also explain how poverty plays a role?
Poverty is important because of the fact that people live in poor-quality dwellings without window screens, or holes in the window screens — I think that is a big one. I think another big one is the fact that it is not just the window screens but the immediate environment around the house in these poor areas — you see environmental degradation, you see uncollected garbage, you see standing bodies of water such as undrained ditches as well as in containers, discarded tires along the side of the road — and so these are the reasons, because all of them are perfect for harboring the Aedes aegypti mosquito.
So it is the poor areas I am most concerned about, which includes Haiti, for instance. I think Haiti is going to get decimated. I am very worried about Haiti. I’m worried about the whole region, but especially about places like Haiti, for the same reasons I am worried about the Gulf Coast, especially the poor areas. Some of the historic wards of Houston — like the 5th ward, Sunnyside — all these places are vulnerable, and that is part of the conversation that you are not really hearing. You are hearing mostly that the West, particularly the U.S., is wealthy, and therefore we don’t have to worry, but I put an asterisk on that and say yes, but the Gulf Coast has an extreme level of poverty that we don’t see in many other parts of the country, and that is uniquely vulnerable to Zika.
Can you explain how the Zika virus and its current transmission rate relates to global health security and its challenges?
We are seeing how destabilizing the Zika virus is — it is causing people to question whether we should even hold the Summer Olympics games — I think that is a big one. It is causing people to worry about the economy of the Caribbean. Could the whole Caribbean economy be decimated since it is so dependent on tourism? It is hurting the airline industry, so it is a big effect on the economy, and it just creates a lot of instability when pregnant women fear that they are going to be affected by the virus.
So it erodes confidence in governments in fragile states like Venezuela. I think this could be a trigger to potentially some major political activity in Venezuela, if enough pregnant women give birth to babies with microcephaly. I think it is further destabilizing the Brazilian government, for instance, a government already under fire for corruption and its economic troubles. And if it hits the U.S. it will affect the U.S. presidential election because people will wonder what the government is doing and why didn’t the government do more to stop this, why didn’t we have vaccines, why didn’t we clean up the Gulf Coast. So I think all of that is going to bring up a lot of those issues as well.
Speaking of vaccines, how far away are we from a vaccine for the Zika virus?
Unfortunately, we are starting from zero. This is a real problem. It’s not even like Ebola, where we had a decade or more of research on vaccines and vaccine development, whereas up until a few months ago not very many people thought this was an important virus until we saw the congenital birth defects. So I think there are very few efforts to develop Zika vaccines.
The good news is that there is a pretty big experience with arbovirus vaccines. We have had a yellow fever vaccine for a long time and I think that is going to be helpful. We have a new dengue vaccine. So I think there is enough experience with arbovirus vaccines but not with Zika. That is the good news. The bad news is that we are starting from zero. The good news is that we have experience with arbovirus vaccines. Bad news again, is that we are going to want to vaccinate impregnated women and the bar is set very high for vaccinating pregnant women.
Will there be a chance for an expedited development process by the FDA for a potential vaccine candidate as there was for Ebola?
I think with pregnant women the FDA’s hands might be tied. It may be just too controversial. The bottom line is that it is years away. I doubt that we are going to have it in time for this epidemic.
What about the eradication of mosquitoes as an option to curb the transmission rate?
I have been writing a bit about the fact that there is a history with this in 1947 and 1962. We eradicated Aedes aegypti in 18 countries and several Caribbean countries and maybe we need to revisit that.
In regard to the microcephaly in Brazil, what about Venezuela and Colombia, where they are seeing rises in Guillain-Barré syndrome versus microcephaly?
Venezuela and Colombia are seeing microcephaly, too. The problem with this outbreak is that there is nothing published. So we are dealing with this very difficult issue because of that.
This week, Colombia attributed three deaths to Guillain-Barré syndrome due to the Zika virus. Do you think that is premature?
I think it is possible but it could be due to Guillain-Barré but whether Guillain Barré was due to Zika — that is a big question.
Many experts are attributing the beginning of this outbreak in Brazil with the increase in the number of tourists that traveled there to attend the 2014 World Cup; however, others think there is a possible link between the release of 25 million of Oxitec’s genetically modified mosquitoes, OX513A, in April 2015, which would correlate better to the time line of the initial Zika virus cases noted by the healthcare workers in Brazil in May of 2015. What are your thoughts concerning these two theories?
I think anytime you talk about some of these factors you have to postulate some plausible mechanism. So, you can imagine with the World Cup, maybe the virus was introduced from a team that was living in an endemic area, but if you look at the history of this virus, it was marching across the Pacific from Micronesia to Polynesia to Easter Island anyway, so I don’t think you have to postulate the World Cup. And then people have said, well it’s not the World Cup; it is the World Canoe event that brought people from Polynesia. So I don’t think we know. Anytime you have big human migrations it could be true to or unrelated. I think judgment is out on that.
In terms of the genetically modified mosquitoes — you know the problem I have is, what is the mechanism? I have trouble identifying what those mechanisms would be — how would a genetically modified mosquito that is not breeding suddenly become more vector competent for Zika virus — which is what the theory is really proposing. Maybe there is a mechanism that I don’t know about, but I haven’t heard it.
For individuals here in Houston and on the Gulf Coast trying to get pregnant now, or within the next year, what would you say to them in relation to their Zika virus risk?
Right now we have no Zika on the Gulf Coast in terms of transmission, but it is something to watch out for. So right now we are not an endemic area, but I think there is a real possibility as we move toward the warmer months that that could happen. So that is something you are just going to have to stay on top of and be vigilant about.
Anything else you think would be important for our readers to know about this virus?
As far as the 2016 Olympic games are concerned, if you are not pregnant then it is fine. People are worried that you could bring it home but I don’t think there is a lot of evidence of transmission by non-vector borne routes at this point—there are some rare instances of it happening but I think it is probably safe.
I also think the Brazilian government could do a lot more during the World Cup and things like that to ensure that people don’t get bitten by infected mosquitoes. We can apply the same eradication techniques for the World Cup site as we did when we achieved it in the past
Is Brazil economically equipped to do that?
I do think the Brazilian government does have the funds.
Hotez is the founding dean of the National School of Tropical Medicine and Professor of Pediatrics and Molecular Virology & Microbiology at Baylor College of Medicine, where he is also the Texas Children’s Hospital Endowed Chair of Tropical Pediatrics. He is also president of the Sabin Vaccine Institute, director of the Texas Children’s Hospital Center for Vaccine Development, and the Baker Institute Fellow in Disease and Poverty at Rice University.
Hotez is an internationally recognized research investigator in neglected tropical disease vaccine development and a renowned global health advocate. He leads the only product development partnership for developing new vaccines for hookworm infection, schistosomiasis, and Chagas disease, diseases affecting hundreds of millions of children and adults worldwide. The hookworm vaccine is currently in clinical trials. In 2006 at the Clinton Global Initiative, he co-founded the Global Network for Neglected Tropical Diseases to provide access to essential medicines for more than 100 million people.
NSTM applies strong traditions in basic, translational and applied biotechnology research brought by the Baylor College of Medicine faculty and staff with the newly affiliated Sabin Vaccine Institute Product Development Partnership (Sabin-PDP). The NSTM works in partnership with Texas Children’s Hospital, home of the Sabin Vaccine Institute & Texas Children’s Hospital Center for Vaccine Development.
NSTM is addressing neglected infections of poverty in the United States through establishing a unique tropical disease clinic in collaboration with the Harris Health System and preventing these infections as they emerge along the Gulf Coast and South Texas. Among the school’s recent discoveries is the finding of dengue fever transmission in Houston, Chagas disease transmission in East and South Texas, and a new clinical syndrome caused by West Nile virus (WNV) infection.