Luminescence will track Third World TB

17 Jun 2002

The onslaught of tuberculosis throughout the developing world could be monitored and controlled, thanks to a portable optical system soon to begin field trials.

The digital Bronx Box identifies the presence of tuberculosis in a saliva sample within a few minutes and is being designed to work in parts of the world far from any sophisticated medical facilities. US-based researchers at InterScience, the University of Albany and the Albert Einstein College of Medicine are developing the device and reported it at the recent Photonics West meeting in San Jose CA.

The system detects luminescence that is emitted when a virus, modified by a light-producing chemical, interacts with live TB bacteria in a sample of saliva. "It not only detects whether TB is there or not but can also tell which strain it is," said James Castracane of University of Albany. The system determines the strain by testing the sample against a combination of drugs. When the light goes out the drugs have successfully killed the bacteria.

The optical system includes a CMOS detector and is designed for sensitive low-light imaging. Castracane says that the system gives close to single-photon sensitivity.

The research, which is funded by the US National Institute of Health, is into its second phase, in which the team is developing devices for field tests. These trials are aimed at making the Bronx boxes portable and rugged, and exploring ways of uploading the digital data to a server via satellite links. Castacane predicts that this phase will last about a year and that products will follow about six months later. The devices will cost between about USD 4000 and USD 5000.

SH