軍團國Outbreak in the Bronx
Cooling towers on building roof tops are believed to be the breeding grounds of bacteria responsible for a summer outbreak of Legionnaires’ Disease in New York City. The outbreak began on July 10. As of August 13, twelve deaths and 119 cases of illness have been attributed to the disease, which is caused by軍團國細菌。目前的爆發是紐約市曆史上最大的，並專注於該市的布朗克斯自治市鎮。8月11日，The New York Timesreporteda Rikers Island (New York) inmate had been diagnosed with Legionnaires’ Disease, but that the case is unlikely to be connected to the outbreak in the Bronx.
軍團國occurs naturally in water and can grow to very high levels in warm water, according to the US Centers for Disease Control and Prevention (CDC). People may be exposed to軍團國when they inhale water vapor or mists from contaminated hot tubs, showers, cooling towers, plumbing systems, decorative pools,water walls和噴泉。軍團國infection may result in Legionnaires’ Disease, a form of pneumonia that can be fatal.
CDC筆記that each year, 8,000 to 18,000 people are hospitalized with Legionnaires’ Disease. Most people exposed to the bacteria do not become sick. According to theNew York City Department of Health and Mental Hygiene website, groups at high risk for Legionnaires’ Disease include people who are middle-aged or older, especially cigarette smokers, people with chronic lung disease or weakened immune systems and people who take medicines that weaken their immune systems (immunosuppressive drugs). The Department notes that all deceased individuals were adults with underlying conditions. Although it is sometimes fatal, the illness can be treated successfully with antibiotics.軍團國細菌不會從人身上傳播給人或通過飲用自來水，但如果軍團國growth is supported in drinking water distribution systems, people can be exposed through contact with water vapor or mists from tap water dispensed through features such as hot tubs, showers and fountains.
冷卻塔通過循環水和空氣的介質去除來自建築物的熱量。在理想的溫度範圍內，可以將水蒸氣和水滴從冷卻塔中排出到周圍環境中軍團國據此，生長（20° - 50°C; 68° - 122°F）US Occupational Safety & Health Administration(OSHA). Cooling towers must be adequately designed and maintained to control the growth of軍團國。
OSHA推薦cleaning and disinfecting cooling towers quarterly or at least twice per year if the unit is not used year-round. This should be done before initial start-up at the beginning of the cooling season and after shut-down in the fall. Protocols for sampling, treating contaminated water systems with chlorine disinfectant, and re-sampling are provided in detail on theOSHAwebsite。
An Action Plan for Addressing Cooling Towers and Legionella
發現有汙染的冷卻塔的布朗克斯建築已被消毒，並被衛生官員監測，according to今日美國。The Rikers Island prison cooling towers and shower heads are being cleaned and disinfected, according toThe New York Times。該市的健康和精神衛生部正在使用“疾病偵探”進行調查華爾街Journal articlereported Governor Cuomo is promising to develop state regulations for testing and disinfecting cooling towers. (The article notes the city has over 2,500 of these structures.) Health officials are educating people in senior centers and homeless shelters about the disease. These are steps in the right direction. Given the fact that reported US軍團國infection cases more than tripled between 2001 and 2012 (Parr et al., 2015)1, let’s act to control the spread of this potentially deadly bacteria from cooling towers.
For more information on the Legionnaires’ Disease outbreak in New York City, please see the New York City Department of Health and Mental Hygienewebsite。
Steve Hubbs retired from water treatment operations at the Louisville Water Company in 2004. He was involved in the development of the first DBP regulation in 1975-1979 and remains an active volunteer in the drinking water community today.
1Parr, A, Whitney, EA, Berkelman, RL (2015). Legionellosis on the Rise: A Review of Guidelines for Prevention in the United States, J Public Health Manag Pract, (5):E17-26. Abstract available:http://www.ncbi.nlm.nih.gov/pubmed/25203696