As a molecular biologist, Chelsea Smartt believes that her research efforts will unlock one mystery behind the recent string of Zika virus disease outbreaks in the Caribbean, Central and South America and some Pacific islands.
Many Florida residents are concerned about the possibility that the Zika virus could eventually become established among local mosquito populations, something that has not happened, so far as experts are aware.
One of Smartt’s primary research goals is to find a novel way of reducing the incidence of mosquito-borne illnesses in the U.S. – by protecting the mosquitoes from becoming infected.
Although people tend to think of mosquito-borne infections as only affecting the hosts that are bitten, the mosquito cannot transmit a pathogen until she has become infected and the micro-organism is teeming through her bodily fluids.
“By using techniques from molecular genetics, I hope to develop a compound that could be fed to female mosquitoes and would block a virus from replicating, or block it from leaving the mosquito’s internal environment,” said Smartt, an associate professor at the Florida Medical Entomology Laboratory in Vero Beach, part of the University of Florida Institute of Food and Agricultural Sciences.
This approach could, theoretically, be applied successfully to any number of pathogens transmitted by mosquitoes. Smartt has already identified a handful of mosquito genes that seem particularly relevant to immune response.
Ultimately, she hopes to develop a compound that could be mixed with sugar water and made available to mosquitoes via feeding stations, similar to the devices used to feed hummingbirds. Adult mosquitoes, both male and female, consume nectar from flowers to obtain sugar needed for energy. If successful, this product concept might prove cost-effective for protecting residents of developing nations from mosquito-borne diseases, although the insects’ appetites might not be affected.
“My strategy won’t stop mosquitoes from biting, but it could eliminate the risk that you’d get anything worse than an itchy welt,” she said.
Smartt’s interest in mosquitoes dates back to her childhood, specifically the years 1972-77, when her family lived in the Northeast African nation of Tanzania.
“While we lived there, my brother contracted malaria during a visit to a village,” she said. “In college, I became interested in molecular biology after taking genetics during my undergraduate study. The idea of studying the molecules that control the makeup of mosquitoes was fascinating to me.”
Smartt’s latest project will take her to Brazil, to study the invasive yellow fever mosquito, Aedes aegypti, and the Asian tiger mosquito, Aedes albopictus, and gain insight on the ability of each species to transmit the Zika virus, as well as the viruses responsible for two other mosquito-borne diseases, chikungunya and Dengue.
In 2015, outbreaks of all three diseases occurred simultaneously in Salvador, capital city of the Brazilian state of Bahia, leaving some residents infected with all three. Smartt and her colleagues are traveling to the Salvador area to visit homes where residents were previously infected with Zika virus; the researchers plan to collect mosquitoes currently residing inside those homes, and then determine whether the insects are infected with any pathogens.
“I want to find out which mosquito species are associated with homes and other places where people spend time in these communities where the Zika virus infections have been found,” Smartt said. “We also plan to evaluate a simple field test that we hope can tell us whether an individual mosquito is carrying any pathogens.”
If the field test proves reliable, Smartt said, it may be possible for public health officials to carry out simple monitoring for mosquito-borne diseases. Such a breakthrough would make it easier for the governments of developing nations to track emerging outbreaks of mosquito-borne diseases, and marshal resources faster and more effectively.
The current Brazil trip is funded by a $10,000 UF/IFAS Mid-Career International Travel Award that Smartt received earlier this year.