Zika: Surveillance and Response

GH_Homepage_headerResearchers have been aware of Zika virus since 1947, but it’s only within the past 10 years that the virus has spread rapidly and caused more than minor illness. Faculty at the Tulane University School of Public Health and Tropical Medicine want to know why and how to respond to it.

A year has passed since the Pan American Health Organization issued a warning in Brazil with the first confirmed Zika infection. The mosquito-borne virus spread gradually over decades through Africa and Asia, picking up speed – and media attention – as it hit Brazil. The world learned quickly that Zika infection during pregnancy could cause microcephaly. The virus will likely spread further through South America and Central America, potentially reaching up into the United States, carried by mosquitoes that that thrive throughout these regions.

ZikaTulane public health researchers, however, may have networks that are just as established as those of the mosquitoes. It is the ability of people in those networks to track Zika down to the mosquito, and the strength of those networks to build capacity for surveillance and response. Such ability and strength enable Tulane researchers to move quickly when emerging diseases try to take hold.

Perfectly Situated to Respond

“The concern about Zika is at the crossroads of many of our priorities at Tulane,” emphasizes Dr. Pierre Buekens, W.H. Watkins Professor and dean of the school. “We’ve been working extensively on diseases transmitted by mosquitoes. This is a disease that is affecting mothers and babies, and we work in maternal and child health. Latin America is a priority region for us. This is exactly what we care about, and we have experts in all these fields.”

In addition to leading SPHTM, Buekens directs the Center for Emerging Reproductive and Perinatal Epidemiology (CERPE). Through CERPE, Buekens and colleagues are planning to launch a study on Zika in pregnancy.

“We want to be able to tell a pregnant woman what the risk is,” he says. The research team chose Honduras because Zika is already present and more cases will likely arise over the summer.

Buekens explains that this information could help researchers, physicians, and parents-to-be better understand the correlation between Zika infection and pregnancy complications or birth defects. “We know there is an association, but we don’t know how frequent it is.”

Multidisciplinary research teams within Tulane are connecting with their collaborators throughout the country and around the world to do the needed research.

“I have been very impressed by the level of cooperation among the researchers here,” says microbiologist Antonito Panganiban, PhD, professor and interim chair of the division of microbiology at the Tulane National Primate Research Center (TNPRC) in Covington, La. At the TNPRC, research teams are working on plans to develop a non-human primate model of Zika in order to find out how the virus is cleared, observe immune response to the virus, study the way in which the virus may cross the placental barrier during pregnancy, and potentially test vaccine or anti-viral compounds in development.

Yet the proposed collaborations between researchers in every aspect of Zika response sometimes remain in a holding pattern as researchers apply for funding to support their efforts. Tulane researchers are applying for private and government research grants. To support the effort, SPHTM development director Verna Aucoin is preparing a social media and email campaign to generate financial support for Zika-related research at Tulane.

PanPim adult mosq

Doctoral student Panpim Thongsripong prepares a BG-sentinel trap, which will attract and capture adult mosquitoes.

Surveilling Mosquitoes Close to Home

Dr. Dawn Wesson has an extensive background in medical and molecular entomology and vector biology, and has served as a principal investigator on projects on vector-borne diseases like dengue, Chagas, West Nile virus, and, now, Zika virus.

Dr. Dawn Wesson has an extensive background in medical and molecular entomology and vector biology, and has served as a principal investigator on projects on vector-borne diseases like dengue, Chagas, West Nile virus, and, now, Zika virus.

Dr. Dawn Wesson, associate professor in the department of tropical medicine, and her students have spent many long years collecting mosquitoes in the New Orleans area. Her team is using their existing surveillance system to try to assess the risk of Zika coming into the area.
Aedes aegypti and Aedes albopictus are the two mosquito species that could carry Zika in Southeast Louisiana. Wesson’s team tracks those two in the field, and then, back in a new, secure mosquito research lab, is infecting mosquitos with the Zika virus in order to observe the transmission process.

“Part of the surveillance involves ovocups. We go out every week to different parts of Orleans, Jefferson, and St. Bernard parishes. Mosquitoes lay eggs on those cups and then we hatch them out and identify them,” she explains. The ovocups contain a sticky surface that attracts mosquitoes and then retains the eggs. Tracking mosquito species at up to 100 locations throughout Orleans and surrounding parishes helps keep local mosquito control boards informed of the highest risk areas.

Ovocups like this are instrumental in Zika surveillance. A sticky surface in the cups attracts mosquitos and retains their eggs that can then be hatched out for identification.

Ovocups like this are instrumental in Zika surveillance. A sticky surface in the cups
attracts mosquitos and retains their eggs that can then be hatched out for identification.

However, Wesson emphasizes that the risk of Zika transmission might not be as large as feared. Measures that people in the United States almost take for granted, such as screens on windows, habitual use of repellant, and public messages to dump out standing water, all help keep the risk of Zika low.

Wesson and her team also have developed a lethal ovitrap, a proven strategy for attracting the vectors of Zika, Dengue, and chikungunya. Wesson is looking for groups in Zika-affected areas who want to partner to use these traps. The traps are used most effectively with a strong community-level effort to control mosquitoes, says Wesson.

Continuing reading Zika: Surveillance and Response >>

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About Tulane University SPHTM

Tulane's School of Public Health and Tropical Medicine is the oldest school of public health in the country and the only American school of tropical medicine. Our mission is to advance public health knowledge, promote health and well-being, and prevent disease, disability, and premature mortality. This is accomplished through academic excellence in education of public health professionals, rigorous scientific research of public health problems, creative partnerships to advance the practice of public health, and innovative service to the local, national, and international public health community.
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