Controlling tuberculosis in an open society.

During a session held at the annual meeting of the American Society of Heating, Refrigerating, and Air-Conditioning Engineers (ASHRAE), an international panel of experts discussed ways of coping with the world's most lethal and infectious disease. Tuberculosis (TB) kills approximately 2.5 million people each year. The panel found that TB control requires the cooperative efforts of the medical and engineering communities, including extensive research into the effects of various technologies on TB transmission.

Four panelists gave presentations:

* Edward A. Nardell, M.D., chief of pulmonary medicine at Cambridge Hospital and professor of TB prevention and control at Harvard Medical School, discussed the disinfection of air as a means of controlling transmission of the virus. One such method is upper-room ultraviolet (UV) germicidal irradiation, which uses short-wavelength (254-nanometer) UV radiation to kill airborne infectious agents. Other engineering control methods include increased ventilation, directional air flow, air filtration, and particulate respirators.

* Melvin W. First, Sc.D., emeritus professor of environmental health engineering at Harvard School of Public Health, described the engineering dimensions of TB control in a New York City homeless shelter project. A study of the project is attempting to correlate protection from transmission of TB with specific UV doses used in upper-room UV irradiation and to develop an engineering guidance manual for designing applications of upper-room UV effective in indoor environments of all types.

* Paul Jensen, Ph.D., P.E., an industrial hygiene engineer at the Centers for Disease Control in West Virginia, reviewed methods of controlling occupational exposure to tuberculosis, including engineering controls in areas where infectious patients may be located. Future work will apply computation fluid dynamic models in the design and evaluation of hospital room architecture and ventilation.

* Bernard Fourie, Ph.D., M.Sc., program leader with the Medical Research Council in Pretoria, South Africa, gave an overview of tuberculosis in South Africa, where the disease rate is up to 60 times higher than in the United States and western Europe. The goal of the South African National Department of Health is to diagnose more than 70 percent of infectious cases and cure at least 85 percent of those identified. Success of this plan requires a comprehensive approach to TB and HIV control. Environmental controls are also important in limiting disease transmission, particularly in high-risk groups such as health care and laboratory workers in peripheral clinics or hospitals, waiting-room staff and visitors, HIV/AIDS care providers, mine workers, prison inmates, and staff at correctional facilities.