[A study on contamination from Legionella spp. at a home for the elderly in Toyohashi City].

Objective: Legionnaires disease has been attributed to Legionella spp. in the water distribution systems of buildings. However, recently cases due to contamination of thermal-bath water have been reported in Japan. In this investigation, we examined the supervision of baths and the presence of Legionella spp. in thermal-bath water of homes for the elderly in Toyohashi city.

Methods: The research was conducted through questionnaires on bathing facilities at 50 sites. Thermal baths were found to be installed at 14 of the sites. We then tested 22 samples from the 14 sites for Legionella spp. and other materials.

Results: From the genus Legionella, only Legionella pneumophila was detected, in 8 samples from 4 sites. Coliforms were also detected. Moreover, disinfectant was not detected in any of the Legionella positive samples of bath water. Legionella positive sites had, however, been replacing their water once a day.

Conclusions: These findings indicate that the use of disinfectant and the proper supervision of bathing facilities are important in controlling Legionella spp. Legionnaires disease can be averted in homes for the elderly through appropriate measures.