A time series study of drug sales and turbidity of tap water in Le Havre, France.

The 80,000 inhabitants of the lower part of Le Havre obtain their water supply from two karstic springs, Radicatel and Saint-Laurent. Until 2000, the Radicatel water was settled when turbidity exceeded 3 NTU, then filtered and chlorinated, whereas the Saint-Laurent water was simply chlorinated. Our study aimed to characterize the link between water turbidity and the incidence of acute gastroenteritis (AGE). Records on drug sales used for the treatment of AGE were collected from January 1994 to June 1996 (period 1) and from March 1997 to July 2000 (period 2). Daily counts of drug sales were modeled using a Poisson Regression. We used data set 2 as a discovery set, identifying relevant (i.e. both significant and plausible) exposure covariates and lags. We then tested this model on period 1 as a replication dataset. In period 2, the daily drug sales correlated with finished water turbidity at both resources. Settling substantially modified the risk related to turbidity of both raw and finished waters at Radicatel. Correlations were reproducible in period 1 for water from the Radicatel spring. Timeliness of treatment adaptation to turbidity conditions appears to be crucial for reducing the infectious risk due to karstic waters.

[1]  P. Beaudeau,et al.  Syndromic surveillance of acute gastroenteritis based on drug consumption , 2010, Epidemiology and Infection.

[2]  Appiah Amirtharajah,et al.  Drinking water turbidity and emergency department visits for gastrointestinal illness in Atlanta, 1993–2004 , 2006, Journal of Exposure Science and Environmental Epidemiology.

[3]  Grant,et al.  BUREAU DE RECHERCHES GÉOLOGIQUES ET MINIÈRES , 2009 .

[4]  Huimin Liu,et al.  Generalized Additive Model , 2008 .

[5]  L. Rodrigues,et al.  The association between drinking water turbidity and gastrointestinal illness: a systematic review , 2007, BMC public health.

[6]  Scott L Zeger,et al.  On the equivalence of case-crossover and time series methods in environmental epidemiology. , 2007, Biostatistics.

[7]  G. Craun,et al.  Observational epidemiologic studies of endemic waterborne risks: cohort, case-control, time-series, and ecologic studies. , 2006, Journal of water and health.

[8]  Manuel J. Rodríguez,et al.  Use of a health information telephone line, Info-santé CLSC, for the surveillance of waterborne gastroenteritis. , 2006, Journal of water and health.

[9]  D. Zmirou-Navier,et al.  Waterborne microbial risk assessment : a population-based dose-response function for Giardia spp. (E.MI.R.A study) , 2006, BMC public health.

[10]  G. Craun,et al.  Estimates of endemic waterborne risks from community-intervention studies. , 2006, Journal of water and health.

[11]  Trevor Hastie,et al.  Generalized Additive Model , 2005 .

[12]  E. Naumova,et al.  Daily variations in effluent water turbidity and diarrhoeal illness in a Russian city , 2003, International journal of environmental health research.

[13]  Ludivine Dussart-Baptista.  Transport des particules en suspension et des bactéries associées dans l'aquifère crayeux karstique haut-normand , 2003 .

[14]  Philip S. Brachman,et al.  Control of Communicable Diseases Manual, 17th Edition , 2001 .

[15]  M. Lacroix,et al.  Forecasting of Turbid Floods in a Coastal, Chalk Karstic Drain Using an Artificial Neural Network , 2001 .

[16]  J. Holt,et al.  Drinking water quality and health-care utilization for gastrointestinal illness in greater Vancouver. , 2000, Canada communicable disease report = Releve des maladies transmissibles au Canada.

[17]  J Schwartz,et al.  Drinking water turbidity and gastrointestinal illness in the elderly of Philadelphia , 2000, Journal of epidemiology and community health.

[18]  P. Beaudeau,et al.  A time series study of anti-diarrheal drug sales and tap-water quality , 1999 .

[19]  J. Schwartz,et al.  Drinking Water Turbidity and Pediatric Hospital Use for Gastrointestinal Illness in Philadelphia , 1997, Epidemiology.

[20]  Paul H. C. Eilers,et al.  Flexible smoothing with B-splines and penalties , 1996 .

[21]  M. Edwardes,et al.  A randomized trial to evaluate the risk of gastrointestinal disease due to consumption of drinking water meeting current microbiological standards. , 1991, American journal of public health.

[22]  D. Zmirou,et al.  A follow-up study of gastro-intestinal diseases related to bacteriologically substandard drinking water. , 1987, American journal of public health.