Respiratory syncytial virus (RSV) sends about 120,000 children to the hospital in the United States each year. Although it is only life-threatening in one case out of every 100, it infects virtually all children by the time they are five. Few children in the U.S. die from RSV but it also attacks the elderly, causing some 17,000 to 18,000 deaths annually. Individuals with impaired immune systems are another highly susceptible group. Worldwide, the virus causes about one million deaths annually.
Current methods of detecting the virus can take from two to six days, postponing effective treatment. The new, high-tech method uses multi-colored, microscopic fluorescent beads, called quantum dots, which bind to molecular structures that are unique to the virus's coat and the cells that it infects. In a paper appearing in the June issue of the journal Nanoletters, the Vanderbilt researchers report that not only can a quantum dot system detect the presence of particles of the respiratory syncytial virus (RSV) in a matter of hours, rather than the two to five days required by current tests, but it is also more sensitive, allowing it to detect the virus earlier in the course of an infection. When an RSV virus infects lung cells, it leaves part of its coat on the cell's surface. Quantum dots have been linked to antibodies keyed to structures unique to RSV's coat. As a result, when quantum dots come in contact with either viral particles or infected cells they stick to their surface.
"The problem with current detection technologies is that they take too long," says Professor of Pediatrics James E. Crowe, Jr. who collaborated with Associate Professor of Chemistry David W.