Tulane Professor Swats at Local Mosquito Problem

September 20, 2003

Chelsea Newton, <i>Hullabaloo</i> contributing writer

Tulane recently received a $2.1 million grant from the National Institute of Health to study patterns of egg-laying preferences in two species of mosquitoes, both known carriers of Dengue Fever and West Nile viruses.

Dr. Dawn Wesson, an associate professor of tropical medicine at Tulane, and her colleagues will conduct these biological studies in New Orleans, where mosquito activity is prevalent. It is determined that female mosquitoes prefer to lay their eggs in water filled containers such as trash cans and rain gutters found throughout New Orleans, making the mosquito population quite large. Wesson's team intends to use the large numbers to their advantage, testing the popular breeding grounds for hormonal trends.

"By sampling larval environments for bacterial cues present in the water, we can dissect which cues are most attractive to females," Wesson said. Wesson and her colleagues will work with Tulane undergraduates to set traps and monitor these hormonal signals within the mosquito population on the Uptown campus. The data they collect will be used to create mosquito traps that will synthesize the indicators. "The National Institute of Health," Wesson said, "wants a tangible result from our research in the form of a product that can out-compete urban containers as a desirable place for female mosquitoes to lay their eggs."

These traps will also be used in conjuncture with conventional bug repellant, both to provide relief from bites, and for population control of pathogen-carrying mosquitoes such as the Asian Tiger Mosquito, one of the main carriers of the West Nile and Dengue viruses. While rare in the United States, the Dengue Fever virus is often called "break bone fever" because victims experience extreme soreness in their joints and bones.

The disease is common in tropical areas of the world, particularly in underdeveloped countries. Millions fall victim to the virus each year, resulting in thousands of deaths. "Those afflicted suffer immensely, including fever and hemorrhagic manifestations." Wesson said.

Both the loss of life and decreased productivity from infected workers could be ameliorated by population control of mosquitoes. Though not as deadly as the Dengue Fever virus, the West Nile virus has received more media attention due to recent outbreaks across the United States.

Introduced to the country five years ago in New York, the virus has since flourished in wet, hot climates, infecting thousands and killing hundreds. In its most serious form, the West Nile virus causes fatal swelling of the spinal chord and brain.

"Unlike the Dengue Fever virus, the West Nile virus' preferred host is not in fact humans, but birds. People are a dead-end host for the West Nile virus," Wesson said. While September is "West Nile Season," Wesson assures Tulane students who may be victim to mosquito bites themselves that most of the mosquitoes in New Orleans are not carriers of either the Dengue Fever or the West Nile virus.

Wesson urges all individuals to exercise caution and wear bug repellant until the cold weather sets in, eliminating the larger parts of the mosquito population.

Tulane University, New Orleans, LA 70118 504-865-5000