Surveillance On Legionella Contamination Of Cooling Water In Places Related To The Olympic Games In Chaoyang District, Beijing

[Objective] To evaluate the condition of Legionella's contamination in places related to the Olympic Games in Chaoyang District and provide basis for preventing and controlling Legionaires' disease. [Methods] 3 hospitals and 44 hotels were selected and water samples were taken from their cooling towers to examine for Legionella each month during July to September 2007 while the cooling towers' environment and the approach to deal with the cooling towers were investigated. [Results] Legionella was detected in 3 hospitals and 26 hotels. The passing rate among 47 units was 38.30%. 265 samples were collected and 76 samples were detected with Legionella. The positive rate was 28.68%. A total of 17 samples were collected from hospitals and 9 were positive. The positive rate was 52.94%; 248 samples were collected from hotels and 67 were positive. The positive rate was 27.02%. Among the 76 positive samples 63 were type LP1 and 7 were type LP2-14. LP I and LP2-14 were both detected from 6 samples. Cooling towers' environment was suitable for the growth of Legionella. The main approach to cooling waters was chemical processing and most of the chemicals' composition was unIcnown.[Conclusions] The contamination of cooling towers with Legionella was serious and the contamination in the hospitals was more serious than that in the hotels. The main type of Legionella was LP I. The approach to deal with the cooling towers should be regulated.