Hellard M E, Sinclair M I, Fairley C K, Andrews R M, Bailey M, Black J, Dharmage S C, Kirk M D
Department of Epidemiology and Preventive Medicine, Monash University, Melbourne, Victoria.
Aust N Z J Public Health. 2000 Jun;24(3):272-5. doi: 10.1111/j.1467-842x.2000.tb01567.x.
To describe an outbreak of Cryptosporidium gastroenteritis in a swimming pool in Melbourne in early 1998 that was not detected through routine surveillance, and discuss difficulties in identifying such outbreaks.
The Water Quality Study (WQS) was a large community-based study of gastroenteritis. Following suspicion of an outbreak of cryptosporidiosis within the study group, due to pool "X", a nested case control study was performed. Each case of Cryptosporidium gastroenteritis was matched with six controls and data from weekly Health Diaries from the WQS were reviewed. The Department of Human Services also instigated active surveillance among patrons at pool "X" using a systematic sample of 50 people from the pool's swim-school enrollment list.
There were seven cases of Cryptosporidium gastroenteritis in the case control study. Five cases and eight controls swam at pool "X" during the outbreak period. The adjusted odds of developing cryptosporidial diarrhoea if an individual swam at pool "X" was 34.5 (CI 2.3-2548). DHS identified another 11 laboratory confirmed cases associated with pool "X" as well as cases not linked to pool "X". 125 cases were identified throughout Melbourne with the suspected involvement of seven swimming pools.
Despite a high odds ratio of developing cryptosporidiosis this outbreak was not detected by routine surveillance methods. Current outbreak detection methods lack sensitivity, specificity or timeliness.
Improved surveillance systems are required if outbreaks of gastroenteritis are to be detected early so an intervention can be instigated to reduce the amount of subsequent illness.
描述1998年初墨尔本一个游泳池发生的隐孢子虫性肠胃炎暴发事件，该事件未通过常规监测被发现，并讨论识别此类暴发事件的困难。
水质研究（WQS）是一项基于社区的大型肠胃炎研究。在研究组内怀疑因“X”游泳池发生隐孢子虫病暴发后，进行了一项巢式病例对照研究。每例隐孢子虫性肠胃炎病例与六个对照匹配，并审查了来自WQS每周健康日记的数据。人类服务部还对“X”游泳池的顾客进行了主动监测，从该游泳池游泳学校的注册名单中系统抽取了50人作为样本。
在病例对照研究中有7例隐孢子虫性肠胃炎病例。在暴发期间，5例病例和8例对照在“X”游泳池游泳。如果一个人在“X”游泳池游泳，患隐孢子虫性腹泻的调整后比值比为34.5（可信区间2.3 - 2548）。人类服务部还确定了另外11例与“X”游泳池相关的实验室确诊病例以及与“X”游泳池无关的病例。整个墨尔本共确定了125例病例，怀疑涉及7个游泳池。
尽管患隐孢子虫病的比值比很高，但此次暴发未通过常规监测方法被发现。当前的暴发检测方法缺乏敏感性、特异性或及时性。
如果要早期发现肠胃炎暴发事件，以便能够采取干预措施减少后续疾病的数量，就需要改进监测系统。
