Tossa Paul, Deloge-Abarkan Magali, Zmirou-Navier Denis, Hartemann Philippe, Mathieu Laurence
Département Environnement et Santé Publique, INSERM ERI 11, Henri Poincaré University, BP 184-54 505 Vandoeuvre lès Nancy, France.
BMC Public Health. 2006 Apr 28;6:112. doi: 10.1186/1471-2458-6-112.
Pontiac fever is usually described in epidemic settings. Detection of Pontiac fever is a marker of an environmental contamination by Legionella and should thereby call for prevention measures in order to prevent outbreak of Legionnaire's disease. The objective of this study is to propose an operational definition of Pontiac fever that is amenable to epidemiological surveillance and investigation in a non epidemic setting.
A population of 560 elderly subjects residing in 25 nursing homes was followed during 4 months in order to assess the daily incidence of symptoms associated, in the literature, with Pontiac fever. The water and aerosol of one to 8 showers by nursing home were characterized combining conventional bacterial culture of Legionella and the Fluorescence In Situ Hybridization (FISH) technique that used oligonucleotides probes specific for Legionellaceae. A definition of Pontiac fever was devised based on clinical symptoms described in epidemic investigations and on their timing after the exposure event. The association between incidence of Pontiac fever and shower contamination levels was evaluated to test the relevance of this definition.
The proposed definition of Pontiac fever associated the following criteria: occurrence of at least one symptom among headache, myalgia, fever and shivers, possibly associated with other 'minor' symptoms, within three days after a shower contaminated by Legionella, during a maximum of 8 days (minimum 2 days). 23 such cases occurred during the study (incidence rate: 0.125 cases per person-year [95% CI: 0.122-0.127]). A concentration of Legionella in water equal to or greater than 10(4).L(-1) (FISH method) was associated with a significant increase of incidence of Pontiac fever (p = 0.04).
Once validated in other settings, the proposed definition of Pontiac fever might be used to develop epidemiological surveillance and help draw attention on sources of Legionella.
庞蒂亚克热通常在流行环境中被描述。庞蒂亚克热的检测是军团菌环境污染的一个标志，因此应采取预防措施以防止军团病的爆发。本研究的目的是提出一个适用于非流行环境中流行病学监测和调查的庞蒂亚克热的操作性定义。
对居住在25家养老院的560名老年受试者进行了为期4个月的跟踪，以评估文献中与庞蒂亚克热相关症状的每日发病率。结合军团菌的传统细菌培养和使用针对军团菌科的寡核苷酸探针的荧光原位杂交（FISH）技术，对养老院中1至8个淋浴喷头的水和气溶胶进行了特征分析。基于流行调查中描述的临床症状及其暴露事件后的时间，制定了庞蒂亚克热的定义。评估庞蒂亚克热发病率与淋浴污染水平之间的关联，以检验该定义的相关性。
庞蒂亚克热的拟议定义关联了以下标准：在被军团菌污染的淋浴后三天内，最多8天（最少2天）出现头痛、肌痛、发热和寒战中至少一种症状，可能伴有其他“轻微”症状。研究期间发生了23例此类病例（发病率：每人年0.125例[95%可信区间：0.122 - 0.127]）。水中军团菌浓度等于或大于10⁴.L⁻¹（FISH方法）与庞蒂亚克热发病率的显著增加相关（p = 0.04）。
一旦在其他环境中得到验证，庞蒂亚克热的拟议定义可能用于开展流行病学监测，并有助于引起对军团菌来源的关注。
