Economic and Health Impacts Associated with a <em>Salmonella</em> Typhimurium Drinking Water Outbreak−Alamosa, CO, 2008

<div><p>In 2008, a large <i>Salmonella</i> outbreak caused by contamination of the municipal drinking water supply occurred in Alamosa, Colorado. The objectives of this assessment were to determine the full economic costs associated with the outbreak and the long-term health impacts on the community of Alamosa. We conducted a postal survey of City of Alamosa (2008 population: 8,746) households and businesses, and conducted in-depth interviews with local, state, and nongovernmental agencies, and City of Alamosa healthcare facilities and schools to assess the economic and long-term health impacts of the outbreak. Twenty-one percent of household survey respondents (n = 369/1,732) reported diarrheal illness during the outbreak. Of those, 29% (n = 108) reported experiencing potential long-term health consequences. Most households (n = 699/771, 91%) reported municipal water as their main drinking water source at home before the outbreak; afterwards, only 30% (n = 233) drank unfiltered municipal tap water. The outbreak’s estimated total cost to residents and businesses of Alamosa using a Monte Carlo simulation model (10,000 iterations) was approximately $1.5 million dollars (range:$196,677–$6,002,879), and rose to$2.6 million dollars (range: $1,123,471–$7,792,973) with the inclusion of outbreak response costs to local, state and nongovernmental agencies and City of Alamosa healthcare facilities and schools. This investigation documents the significant economic and health impacts associated with waterborne disease outbreaks and highlights the potential for loss of trust in public water systems following such outbreaks.</p> </div

Total costs associated with an outbreak of salmonellosis, Alamosa, Colorado 2008.

<p>Details provided in <a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0057439#pone-0057439-t001" target="_blank">Tables 1</a>, <a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0057439#pone-0057439-t006" target="_blank">6</a> & <a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0057439#pone-0057439-t008" target="_blank">8</a>. Extrapolation done using Monte Carlo simulation model. See main text and Supporting Information in File S1 for details.</p

Potential long-term health consequences of <i>Salmonella</i> infection reported by survey respondents that were ill with diarrhea (≥2 loose stools during a 24-hour period) (n = 369) during an outbreak of salmonellosis, Alamosa, Colorado 2008.

*<p>As reported by 43/52 with skin problems, 36/51 with joint problems, 27/32 with urinary tract problems, 16/19 with eye problems, and 5/6 with abscesses.</p>†<p>As reported 36/52 with skin problems, by 22/51 with joint problems, 15/32 with urinary tract problems, 13/19 with eye problems, and 4/6 with abscesses.</p>‡<p>Questions were not asked.</p

Health insurance payments for Alamosa City residents that sought healthcare during an outbreak of salmonellosis, Alamosa, Colorado 2008.

*<p>Because data were obtained from the hospital only, clinic/doctor’s office visit costs only include laboratory but not physicians’ fees.</p>†<p>We have removed the background rate of diarrhea in the population (5%) to get the percent of illness due to outbreak (21%−5% = 16%). The number of ill persons was the denominator for subsequent proportions who incurred the costs (e.g., 29%,71%, 21% and 8%).</p>‡<p>Costs extrapolated to the City of Alamosa as: total population (N = 8,746)×% incurring costs (column 3 above)×cost distribution (Table S3 in File S1) using a Monte Carlo simulation model with 10,000 iterations. Total cost derived from median of 10,000 iterations and range represents the 5^th to 95^th percentiles of the 10,000 iterations of the Monte Carlo simulation model. See main text and Supporting Information (in File S1) for details.</p

Number and percent of households that reported using various alternate water sources (n = 771 households)^* during an outbreak of salmonellosis, Alamosa, Colorado 2008.

*<p>Questions allowed for multiple options and therefore row totals do not sum to 100%.</p>†<p>e.g., a friend’s house, hotel, or artesian spring.</p>‡<p>e.g., using chlorine or a filter.</p

Reasons households cited for switching from tap water as a main drinking water source to bottled water as a main drinking water source (n = 249) or installing a new water filter (n = 114) after an outbreak of salmonellosis, Alamosa, Colorado 2008.

*<p>Categories are not mutually exclusive so percentages can sum to >100%.</p

Outbreak-associated costs to City of Alamosa businesses associated with an outbreak of salmonellosis, Alamosa, Colorado 2008.

*<p>Costs extrapolated to the City of Alamosa as: total businesses on municipal water (N = 156)×% incurring costs (column 3 above)×cost distribution (Table S3 in File S1) using a Monte Carlo simulation model with 10,000 iterations. Total cost derived from median of 10,000 iterations and range represents the 5^th to 95^th percentiles of the 10,000 iterations of the Monte Carlo simulation model. See main text and Supporting Information (in File S1) for details.</p

Household survey response rate.

<p>Household survey response rate.</p

Costs to City of Alamosa households associated with an outbreak of salmonellosis, Alamosa, Colorado 2008.

*<p>Respondents who incurred cost <u>and</u> reported an estimate of that cost (not every respondent who reported incurring a cost provided the specific cost estimate).</p>†<p>Costs extrapolated to the City of Alamosa as: total individuals/households in City of Alamosa (from census)×% incurring costs (column 3 above)×cost distribution (Table S3 in File S1) using a Monte Carlo simulation model with 10,000 iterations. Total cost derived from median of 10,000 iterations and range represents the 5^th to 95^th percentiles of the 10,000 iterations of the Monte Carlo simulation model. See main text and Supporting Information (in File S1) for details.</p

Number and percent of households that reported using <i>any</i> tap water for the following purposes during the various water advisories (n = 771 households) associated with an outbreak of salmonellosis, Alamosa, Colorado 2008.

*<p>During the bottled water advisory, residents were told to use bottled water for drinking, cooking, brushing teeth, and dishwashing but that if no bottled water was available they could boil their water.</p>†<p>During the Do Not Use order, while the distribution system was being hyperchlorinated, residents were told to only use their tap water for flushing toilets.</p>‡<p>During the boil water advisory, residents were told to boil their water before using it for drinking, cooking, or brushing teeth.</p