TWO maps at the Web site for the Centers for Disease Control and Prevention tell the story of how the West Nile virus has spread across the lower 48 states since it appeared on the East Coast in 1999.
One map shows that in 2003, all but three states reported at least one person infected with the disease, which is most commonly transmitted by mosquitoes. The second map indicates that so far in 2004, 30 states have reported finding the virus in at least one human, mosquito, animal or bird.
But neither map tells people which areas of a particular state to avoid. A note accompanying the maps explains that when a West Nile virus infection is reported to the centers "in any area of a state, that entire state is shaded accordingly."
Pinpointing the location of a West Nile outbreak is often slow and difficult because identifying mosquitoes collected in the field typically takes days. Researchers, sometimes working in unfamiliar territory, must first gather the insects and then bring them back to a laboratory where a technician will study them and test them for viruses.
Now researchers at East Carolina University in Greenville, N.C., are investigating whether they can speed up the tracking of disease-carrying mosquitoes by sharing their expertise with the general public through wireless computers.
"We need to bring the skills to do this work to more people so we can streamline what is now a lengthy process," said Alice Anderson, an assistant professor of environmental health at East Carolina who has studied mosquitoes in North Carolina for the past 20 years and is one of the leaders of the research project. "The more people we have collecting information and the more information we have, the more successful we're going to be in preventing a disease."
Beginning this fall, in a test of the new mosquito identification system, researchers will take to the woods and fields of eastern North Carolina using wireless wearable computers outfitted with digitized images of different bugs. The idea is that when someone comes upon an unfamiliar mosquito, they can identify it by comparing the collected specimen with the digital mosquito image on their computer screen.
The images are more than just simple photographs of bugs, Dr. Anderson said. "They're dynamic and interactive. It's sort of like a video game."
For example, users can turn the picture of the mosquito over to view it from another angle, she said, or they can click on a certain part to get a close-up of that area. "You can compare individual parts of the image of the mosquito with what you're actually seeing," she said.
To further help in the identification, the model will be interactive, asking users simple questions like: "Does the mosquito have three long things on the end of its head, or just one?" or "Is abdomen pointed at the tip, or is it flat across?" Each answer eliminates certain species until a match is made, Dr. Anderson said.
The computers will also be outfitted with Global Positioning System receivers, which will allow health officials to pinpoint specific areas where virus-carrying mosquitoes live and breed. J. Barry DuVall, director of East Carolina's Center of Wireless and Mobile Computing, said the hope is that eventually those positions will be transmitted in real time, so that in the future, the C.D.C's map might be able to tell people the exact location of an outbreak of the West Nile virus.
"Imagine having an up-to-the-moment Web site that has a complete footprint of virus activity worldwide," Dr. DuVall said.
The test in North Carolina this fall will employ two wearable computers on loan from the Army. Using a wearable computer allows users to keep their hands free to handle the mosquitoes at the same time they are looking at the digital images on a large screen projected in front of them, said Anthony G. Gutierrez, chief of the Army's Molecular Biology Laboratory and an adviser to the project.
But a wearable computer also has its drawbacks, Dr. Gutierrez said. "They're expensive, they're not convenient, and you look like a cyborg wearing one," he said. "And it's really easy to get tangled up in the woods."
In the long run, he envisions a reliance on less expensive hardware like hand-held organizers so that the identification system can be used in poor regions of the world afflicted by malaria and other mosquito-borne illnesses. A lighter and cheaper system could also be useful to soldiers stationed in remote areas, Dr. Gutierrez said, or could have commercial uses. For instance, hikers may one day bring along a hand-held organizer that can locate the latest outbreaks of West Nile virus or accurately identify the mosquitoes that could cause them to become ill.
Dr. Anderson hopes that the technology and the mosquito identification system will be simple enough to understand that anyone, including children on school field trips, can use it. To that end, the test in North Carolina will use students from a class at the university. Researchers will record the time it takes students to adjust to the devices and whether they can accurately identify the mosquitoes with the key provided.
"We want to see how the learning of the whole process goes with students," Dr. Anderson said, "because in the end it's the public that will be on the front lines of identifying and controlling these mosquito-borne illnesses."