Airborne bacteria in pools linked with infections

nfections with bacteria in the Mycobacteria family, which includes disease such as tuberculosis, are spread in warm-water therapy pools by becoming airborne, and current methods of checking contamination of these facilities are "seriously inadequate," according to the results of a new study.

In March 2000, workers at a therapy pool in a Midwestern hospital began complaining of respiratory problems. Ultimately, the workers were diagnosed with non-tuberculosis infections with Mycobacteria.

To investigate this disease outbreak, Dr. Largus T. Angenent, from Washington University in St. Louis, and colleagues collected and analyzed samples taken from the pool water, the walls around and the air just above the pool.

The researchers' findings are reported in the Proceedings of the National Academy of Sciences.

Even though the pool used a state-of-the-art disinfection system, bacterial levels in the pool water were fairly high compared with levels in the water used to fill the pool, the investigators report.

The authors found that direct microscopic counts of microbes at all sites were much higher than in cultured samples. The results of genetic tests indicated the presence of Mycobacteria. Moreover, compared with other waterborne bacteria, these bacteria were more likely to be airborne.

The study findings "strongly validate" that the pathogens spread through the air in this environment, the investigators note.

The findings also show that the methods "currently used by public health facilities and agencies are seriously inadequate for the detection and enumeration of potential pathogens."

SOURCE: Proceedings of the National Academy of Science, March 14, 2005.