Technology Targets Lyme-Infested Ticks

America's space agency is biting back against Lyme disease -- now the most commonly reported vector-borne disease - transmitted by a variety of insects and ticks - in the United States. NASA and other scientists are using remote-sensing satellites and advanced computer technology to identify regions where people are most at risk.

Lyme disease is transmitted to humans by infected deer ticks. It can result in debilitating arthritis, and life-threatening neurological and cardiac disorders, but it is preventable with vaccinations or by using insecticides. Using the information, health agencies can now warn people living in high-risk areas to take precautions, said Fish.

There are 9,000 cases of Lyme disease reported each year in the United States. Because the highest concentration of reports come from Westchester County, N. Y., the research team started there. They combined Landsat imagery with geographic information system technology, which uses layers of maps to display spatial relationships between different land features.

The scientists created a map of landcover for all of Westchester County that identified types and placement of landscape elements associated with Lyme disease risk. They found a greater risk of transmission in places with a higher proportion of vegetated residential area next to woods.

"This new method of getting information has given us a complete picture of the high risk areas throughout the county, without sending teams of people into the field," said Fish. Westchester County covers more than 450 square miles.

The team is now working to develop a predictive model that can be applied to other parts of the Northeast, the region where most Lyme disease cases are reported. They are also taking a closer look at Westchester County, said research scientist Sheri Dister.

Disease-tracking technology

Changes in society, technology and the environment, together with the diminished effectiveness of certain approaches to disease control, are expanding the spectrum of infectious diseases. And many infectious diseases once thought to be under control -- such as cholera, yellow fever and tuberculosis -- are now increasing, reports the Center for Disease Control and Prevention in Atlanta.

The center wrote in an April 1994 report that it's time to use high-tech tools to survey emerging and re-emerging infectious disease in the United States. "Like radar or 'early warning' systems that detect threats to national security, surveillance with appropriate laboratory support is a critical element in the effective defense against disease," the report said.

NASA's Lyme disease project in Westchester County is a case in point, said Dr. Joan Vernikos, director of the space agency's Life and Biomedical Science and Applications Division in Washington, D.C. "This particular innovative approach shows the significant contribution NASA can make in the surveillance and prediction of emerging diseases."

--Liz Skinner