Rapidly measured indicators of recreational water quality are predictive of swimming-associated gastrointestinal illness.Standard methods to measure recreational water quality require at least 24 hr to obtain results, making it impossible to assess the quality of water within a single day. Methods to measure recreational water quality in [less than or equal to] 2 hr have been developed. Application of rapid methods could give considerably more accurate and timely assessments of recreational water quality. We conducted a prospective study of beachgoers at two Great Lakes Great Lakes, group of five freshwater lakes, central North America, creating a natural border between the United States and Canada and forming the largest body of freshwater in the world, with a combined surface area of c.95,000 sq mi (246,050 sq km). beaches to examine the association between recreational water quality, obtained using rapid methods, and gastrointestinal (GI) illness after swimming. Beachgoers were asked about swimming and other beach activities and 10-12 days later were asked about the occurrence of GI symptoms. We tested water samples for Enterococcus enterococcus /en·tero·coc·cus/ (en?ter-o-kok´us) pl. enterococ´ci an organism belonging to the genus Enterococcus.
Enterococcus /En·tero·coc·cus/ ( and Bacteroides species using the quantitative polymerase chain reaction Quantitative polymerase chain reaction (qPCR) is a modification of the polymerase chain reaction used to rapidly measure the quantity of DNA, complementary DNA or ribonucleic acid present in a sample. (PCR PCR polymerase chain reaction.
polymerase chain reaction
Polymerase chain reaction (PCR) ) method. We observed significant trends between increased GI illness and Enterococcus at the Lake Michigan beach and a positive trend for Enterococcus at the Lake Erie Lake Erie
Great Lake; once so polluted, referred to as Lake Eerie. [Am. Hist.: NCE, 887]
See : Filth beach. The association remained significant for Enterococcus when the two beaches were combined. We observed a positive trend for Bacteroides at the Lake Erie beach, but no trend was observed at the Lake Michigan beach. Enterococcus samples collected at 0800 hr were predictive of GI illness that day. The association between Enterococcus and illness strengthened as time spent swimming in the water increased. This is the first study to show that water quality measured by rapid methods can predict swimming-associated health effects. Key words: bathing beaches, cohort studies, diarrhea, gastrointestinal diseases, Great Lakes Region The Great Lakes region can refer to:
Swimming in coastal waters is a favored pastime in the United States United States, officially United States of America, republic (2005 est. pop. 295,734,000), 3,539,227 sq mi (9,166,598 sq km), North America. The United States is the world's third largest country in population and the fourth largest country in area. . In a survey of > 75,000 households, 42% of respondents [greater than or equal to] 3 16 years of age, equivalent to approximately 89 million individuals, reported swimming in recreational waters annually (National Survey on Recreation and the Environment 2000-2002). Such waters are often contaminated contaminated,
v 1. made radioactive by the addition of small quantities of radioactive material.
2. made contaminated by adding infective or radiographic materials.
3. an infective surface or object. by human sewage as a result of discharges or overflows [U.S. Environmental Protection Agency Environmental Protection Agency (EPA), independent agency of the U.S. government, with headquarters in Washington, D.C. It was established in 1970 to reduce and control air and water pollution, noise pollution, and radiation and to ensure the safe handling and (EPA EPA eicosapentaenoic acid.
n.pr See acid, eicosapentaenoic.
n. ) 2001]. Swimming in fecally contaminated recreational waters has consistently been associated with gastrointestinal (GI) illness (Pruss 1998; Wade et al. 2003). The incidence of illness attributable to recreational water exposure appears to be increasing. The Centers for Disease Control and Prevention Centers for Disease Control and Prevention (CDC), agency of the U.S. Public Health Service since 1973, with headquarters in Atlanta; it was established in 1946 as the Communicable Disease Center. (CDC See Control Data, century date change and Back Orifice.
CDC - Control Data Corporation ) reported 21 recreational water outbreaks in 2000, more than any single previous year since systematic surveillance began (Lee et al. 2002). The Natural Resources Defense Council The Natural Resources Defense Council (NRDC) is a New York City-based, non-profit non-partisan international environmental advocacy group, with offices in Washington, D.C., San Francisco, Los Angeles, Chicago, and Beijing. Founded in 1970, NRDC today has 1. (Dorfman 2005) reported that there were more beach closings and advisories in 2000 than in any previous year; 85% of these closings and advisories were due to bacteria levels that exceeded standards.
Because of the great diversity of pathogenic microorganisms transmitted by contaminated water and the difficulty and cost of directly measuring all microbial microbial
pertaining to or emanating from a microbe.
the breakdown of organic material, especially feedstuffs, by microbial organisms. pathogens in environmental samples, organisms that may indicate the presence of sewage and fecal contamination (indicator organisms) are often used for monitoring and regulation of recreational and drinking waters. Indicator organisms are common inhabitants
The game is based loosely on the concepts from SameGame. of the intestinal tract of warm-blooded animals. They are found in fecal material at high concentrations and are easier to measure in the environment than are pathogens. Although indicator organisms do not cause illness under normal conditions
Current recreational water-quality guidelines are based on studies conducted in the 1970s and 1980s (Cabelli et al. 1975, 1979, 1982; Dufour 1984). The currently recommended bacterial indicators are based on microbiological methods that involve culturing fecal indicator bacteria Each gram of human feces contains approximately 10 billion (109) bacteria, among them may include pathogenic bacteria, such as Salmonella, associated with gastroenteritis. In addition, feces may contain pathogenic viruses, protozoa and parasites. , such as Enterococcus spp. or Escherichia coli Escherichia coli (ĕsh'ərĭk`ēə kō`lī), common bacterium that normally inhabits the intestinal tracts of humans and animals, but can cause infection in other parts of the body, especially the urinary tract. , and counting the colony-forming units. One shortcoming short·com·ing
A deficiency; a flaw.
a fault or weakness
Noun 1. of these methods is that the bacteria require at least 24 hr to grow visible colonies, making it impossible for beach managers to assess the quality of water on the day of sample collection.
Because microbial water quality can change rapidly (Boehm et al. 2002), guidelines based on indicator organisms that require 24 hr to develop are likely to result in both unnecessary beach closings and the exposure of swimmers to poor-quality water. A recent study estimated that up to 40% of beach closures are in error (Kim and Grant 2004).
In 2000, Congress passed an amendment to the Clean Water Act, the Beaches Environmental Assessment and Coastal Health (BEACH) Act (2000). Among other provisions, the BEACH Act required the U.S. EPA to conduct research to provide the support of new criteria for recreational waters. Methods have been developed to measure microorganisms more rapidly. A modified version of polymerase chain reaction polymerase chain reaction (pŏl`ĭmərās') (PCR), laboratory process in which a particular DNA segment from a mixture of DNA chains is rapidly replicated, producing a large, readily analyzed sample of a piece of DNA; the process is (PCR), quantitative TaqMan PCR (QPCR QPCR Quantitative Polymerase Chain Reaction ; Applied Biosystems Applied Biosystems, Inc. (formerly NASDAQ: ABIO) is the original name of a pioneer biotechnology company founded in 1981 in Foster City, California, among the Silicon Valley cities of the southern San Francisco Bay Area. , Foster City, CA), has been developed to quantify indicator bacteria in recreational waters (Santo Domingo Santo Domingo, pueblo, United States
Santo Domingo (sän'tə dəmĭng`gō), pueblo (1990 pop. 2,866), Sandoval co., N central N.Mex., on the Rio Grande; founded c.1700 after earlier pueblos were destroyed by floods. et al. 2003) in [less than or equal to] 2 hr. Because these methods provide a faster assessment of water quality, they have the potential to significantly reduce illnesses resulting from exposure to recreational waters and also to reduce errors in beach closings or public notifications.
In 2003, we conducted the first in a series of studies designed to evaluate the ability of QPCR to predict health effects of recreational-water exposure. Secondary goals were to evaluate specific study design and analytical methods, such as methods for averaging indicator values, assignment of exposure measures to swimmers, and swimming definitions.
Materials and Methods
We conducted a prospective cohort study of beachgoers at two beaches in the Great Lakes region. One beach was located in the Indiana Dunes National Lakeshore Indiana Dunes National Lakeshore: see National Parks and Monuments (table). , in Indiana, on Lake Michigan (beach A), and the second was located near Cleveland, Ohio "Cleveland" redirects here. For the Cleveland metropolitan area, see . For other uses, see Cleveland (disambiguation).
Cleveland is a city in the U.S. state of Ohio and the county seat of Cuyahoga County, the most populous county in the state. , on Lake Erie (beach B). The study consisted of a health survey of beachgoers and water-quality evaluation.
The beaches were selected specifically because they were affected by discharges from waste treatment plants. The sources of fecal contamination affecting beach A are wastewater treatment plant Wastewater treatment plant also called wastewater treatment works
Unit processes used to separate, modify, remove, and destroy objectionable, hazardous, and pathogenic substances carried by wastewater in solution or suspension in order to render the water fit and safe for intended uses. plant discharges into Lake Erie to the east and west. An outfall out·fall
The place where a sewer, drain, or stream discharges.
Brit, Austral & NZ the mouth of a river, drain, or pipe: about 7 miles to the west discharges 6.5 million gallons of wastewater per day. Within 5 miles to the east of the beach, two other wastewater treatment plants discharge about 40 million gallons of treated sewage per day.
The study design, questionnaires, and materials were reviewed and approved by an Institutional Review Board for the CDC. All participants provided verbal informed consent before enrollment. We complied with all applicable ethical requirements, in accordance with all federal regulations for the protection of human subjects, in conducting this study.
Beachgoer health surveys. The health survey was administered in three parts: enrollment, beach interview, and telephone interview. Interviewers approached beachgoers on weekends and holidays during the summer. Beachgoers who agreed to participate provided verbal informed consent and returned to complete the beach interview as they left the beach. An adult ([greater than or equal to] 18 years of age) answered questions for other household members. The beach interview included questions about demographics, swimming and other beach activities, consumption of raw or undercooked meat or runny run·ny
adj. run·ni·er, run·ni·est
Inclined to run or flow: runny icing; a runny nose.
[-nier, -niest eggs, chronic illnesses, allergies, acute health symptoms in the past 48 hr, contact with sick persons in the past 48 hr, other swimming in the past 48 hr, and contact with animals in the past 48 hr. The telephone interview was conducted 10-12 days after the beach visit, and an adult [greater than or equal to] 18 years of age answered questions for other household members who visited the beach. The telephone interview consisted of questions about health symptoms experienced since the beach visit, and other swimming- or water-related activities, contact with animals, and consumption of high-risk foods since the beach visit. Bilingual (English-Spanish) interviewers were available. Interviews were conducted at beach A between 1 June 2003 through 3 August 2003 and at beach B between 2 August 2003 and 14 September 2003.
Although respiratory, ear, eye, and skin rash symptoms were also evaluated, we present results only for GI illness. GI illness was defined as any of the following: diarrhea (three or more loose stools in a 24-hr period), vomiting vomiting, ejection of food and other matter from the stomach through the mouth, often preceded by nausea. The process is initiated by stimulation of the vomiting center of the brain by nerve impulses from the gastrointestinal tract or other part of the body. , nausea and stomachache stom·ach·ache
Pain in the stomach or abdomen.
stomachache Vox populi Gastralgia , and nausea or stomachache that affect regular activity (inability to perform regular daily activities). This definition of GI illness is consistent with definitions used in recent studies (Colford et al. 2002; Payment et al. 1991, 1997).
Water sample collection and analysis.
Water samples were collected on each study day. Three times a day (0800 hr, 1100 hr, and 1500 hr), two water samples were collected at beach A along each of three transects perpendicular to the shoreline, one in wais-thigh water (1 m deep) and one in shin-high water (0.3 m deep). A representation of the sampling locations and additional details of the sampling protocol have been described previously (Haugland et al. 2005). Transects were located [greater than or equal to] 60 m apart to include the area used by most beachgoers. Water samples were collected at beach A on weekends and holidays during the period from 31 May 2003 through 3 August 2003. Samples also were collected three times a day at nine beach B locations. Because jetties divided the beach and prevented free circulation of water, additional samples were collected to characterize the beach (Haugland et al. 2005). Samples were kept on ice at 1-4[degrees]C during the time before analysis.
A detailed description of sample preparation and QPCR analysis for Enterococcus spp. has been described elsewhere (Haugland et al. 2005). Primers and probes for the Bacteroides analyses were conducted as described by Dick and Field (2004), and analyses were conducted using conditions described by Haugland et al. (2005). Additional details regarding the estimation of cell equivalents have also been described (Applied Biosystems 1997). In brief, we used QPCR to detect and quantify Enterococcus and Bacteroides in water samples based on the collection of these organisms on membrane filters, extraction of their total DNA DNA: see nucleic acid.
or deoxyribonucleic acid
One of two types of nucleic acid (the other is RNA); a complex organic compound found in all living cells and many viruses. It is the chemical substance of genes. , and PCR amplification (i.e., a process whereby the quantity of DNA is doubled in each cycle of amplification) of a genus-specific DNA sequence DNA sequence Genetics The precise order of bases–A,T,G,C–in a segment of DNA, gene, chromosome, or an entire genome. See Base pair, Base sequence analysis, Chromosome, Gene, Genome. using the TaqMan PCR product detection system. The reactions were performed in a specially designed state-of-the-art thermal cycling instrument (SMART Cycler TD System, Cepheid, Sunnyvale, CA) that automates the detection and quantitative measurement of the fluorescent signals produced by probe degradation during each cycle of amplification. Cell equivalents were estimated by comparing the cycle threshold to standard samples containing a known quantity of the target organism cells. If no threshold was achieved after 45 cycles, the sample was considered below the limit of detection. Because a separate set of calibrator calibrator
an instrument for dilating a tubular structure or for determining the caliber of such a structure. reactions was conducted for each test sample, the limit of detection (LOD Lod (lōd), city (1994 pop. 51,200), central Israel. It is also known as Lydda. Its manufactures include paper products, chemicals, oil products, electronic equipment, processed food, and cigarettes. ) can vary from sample to sample. This process has been described previously (Applied Biosystems 1997; Haugland et al. 2005). Water samples were filtered at the local laboratory (Great Lakes Scientific, Inc., Stevensville, MI, and Cuyahoga County Sanitary Engineering
EMSL European Microwave Signature Laboratory
EMSL Environmental Molecular Science Laboratory (operated by Battelle for the US DoE; Pacific Northwest National Laboratory) Analytical Inc. Laboratory, Westmont, NJ) for QPCR analysis. Results for the QPCR analyses are expressed as QPCR cell equivalents (QPCRCE) per 100-mL volume.
Dam analysis. We created two variables to represent exposure to indicator organisms: an average of all measures collected by day, and an average of measures specific to day and reported swimming location. The base 10 log ([log.sub.10]) of the geometric mean (mathematics) geometric mean - The Nth root of the product of N numbers.
If each number in a list of numbers was replaced with their geometric mean, then multiplying them all together would still give the same result. (the mean of the [log.sub.10] of the count) was used for averaging results. Measures below the LOD were assigned values using maximum likelihood, assuming a lognormal distribution Lognormal distribution
Pattern of frequency of occurrence in which the logarithm of the variable follows a normal distribution. Lognormal distributions are used to describe returns calculated over periods of a year or more. (El-Shaarawi and Viveros 1997). Quantile-quantile plots confirmed the approximate log-normal distribution In probability and statistics, the log-normal distribution is the single-tailed probability distribution of any random variable whose logarithm is normally distributed. If Y is a random variable with a normal distribution, then X = exp(Y of the water-quality measures, which are often approximately log-normally distributed (El-Shaarawi 1989; El-Shaarawi and Viveros 1997; Noble et al. 2003). We defined swimming in three ways: "any contact" included anyone reporting contact with water; and "body immersion" and "head immersion" included swimmers who reported a minimum of immersing their body or head, respectively.
We used logistic regression In statistics, logistic regression is a regression model for binomially distributed response/dependent variables. It is useful for modeling the probability of an event occurring as a function of other factors. to model the effect of swimming and water quality on illness. Models included continuous measures of water quality as predictor variables and a 0/1 indicator of illness as the outcome. We used nested interaction terms to allow contrasts among swimmers and between swimmers and nonswimmers. To evaluate the overall risk associated with swimming, we excluded the water-quality measures from the models. We determined odds ratios (ORs) by taking the exponent of the regression coefficients from the logistic regression models. We estimated adjusted predicted probabilities from logistic regression models, holding covariates constant at their mean.
Variables that were related to GI illness or swimming in tabulations, or were suspected by investigators to correlate with GI illness, were considered for regression models. As a result, we evaluated the following variables in initial models: age; sex; race; allergies; swimming within 48 hr before the beach visit or between the beach visit and telephone interview; contact with animals; contact with persons with GI illness; consumption of raw meat, fish, or undercooked eggs; presence of chronic GI illness, skin conditions, or asthma; frequency of beach visits; and use of nose plugs. We excluded from the analysis beachgoers who reported any GI symptoms within 48 hr of the beach visit.
We selected final regression models using backward deletion as described by Rothman and Greenland (1998). Initially, all covariates were included in the model. Covariates were then removed in an iterative it·er·a·tive
1. Characterized by or involving repetition, recurrence, reiteration, or repetitiousness.
2. Grammar Frequentative.
Noun 1. fashion until removal of any remaining covariates resulted in > 5% change in the exposure-illness relationship.
We used SAS (1) (SAS Institute Inc., Cary, NC, www.sas.com) A software company that specializes in data warehousing and decision support software based on the SAS System. Founded in 1976, SAS is one of the world's largest privately held software companies. See SAS System. , version 8.0 (SAS Institute SAS Institute Inc., headquartered in Cary, North Carolina, USA, has been a major producer of software since it was founded in 1976 by Anthony Barr, James Goodnight, John Sall and Jane Helwig. , Cary, NC), S-plus, version 6.1 (Insightful Corp. 2002), and Stata, version 8.2 (Stata Corp., College Station, TX) for data analysis.
We interviewed beachgoers at beach A from 1 June 2003 through 3 August 2003 on weekends and holidays, for a total of 20 days.
We interviewed beachgoers at beach B from 2 August 2003 through 14 September 2003, for a total of 13 days. At beach B, no interviews were conducted because of bad weather on 17 August and 1 September. There were 5,796 household interview attempts at both beaches. The household interviewing response rate (completed/attempted) through the completion of the telephone interview was 56%. Data were available for a total of 3,221 households (5,717 individuals), 1,639 households (2,840 individuals) at the Lake Erie beach (beach B), and 1,582 households (2,877 individuals) at the Lake Michigan beach (beach A). After excluding subjects with GI illness at baseline, data were available for 5,667 individuals.
Water quality. QPCRCE results for the measurements of indicator organisms on study days are shown in Table 1. The QPCRCE for Bacteroides was considerably higher than that for Enterococcus, although there were more results below the LOD for Bacteroides. At beach A, 28% of Bacteroides samples were below the LOD, and at beach B, 21% of Bacteroides samples were below the LOD. Enterococcus QPCRCE at beach A was slightly higher than at beach B (p = 0.06). There was no difference in Bacteraides QPCRCE between beach A and beach B.
Swimming and GI illness. The incidence of GI illness among swimmers and nonswimmers is shown in Table 2. At beach A, the incidence of GI illness was 10% among swimmers, compared to 5% among nonswimmers. At beach B, the incidence among swimmers ranged from 12% for those with any contact with water and to 14% for those who immersed their head, compared to 10% in nonswimmers. Fewer beachgoers reported swimming at beach B than at beach A: at beach A, 75% of respondents reported contact with water, whereas only about 50% reported contact with water at beach B. GI illness was associated with swimming at both beaches. At beach A, those with any contact with water were almost twice as likely to have GI illness compared with nonswimmers [adjusted OR (AOR AOR
The ISO 4217 currency code for Angolan Reajustado Kwanza. ) = 1.96; 95% confidence interval confidence interval,
n a statistical device used to determine the range within which an acceptable datum would fall. Confidence intervals are usually expressed in percentages, typically 95% or 99%. (CI), 1.33-2.90]. Those immersing their body and head were at slightly higher risk (for body immersion: AOR= 2.26; 95% CI, 1.51-3.39; for head immersion: AOR = 2.14; 95% CI, 1.41-3.27). The risk of GI illness associated with swimming was slightly less at beach B (for head immersion: AOR = 1.50; 95% CI, 1.06-2.13).
At both beaches, swimmers were younger, more likely to be male, more likely to eat food or consume beverages at the beach, and more likely to report allergies. At beach A, swimmers were more likely to have consumed raw or undercooked meat within 48 hr of the beach visit, more likely to have had contact with known or unknown animals, and slightly less likely to report chronic GI illness (1.2% vs. 2.2%). At beach B, nonswimmers were more likely to have GI symptoms at baseline (3.4% vs. 1.7%) and more likely to report asthma.
Water quality and GI illness. Table 3 shows the associations between QPCRCE and the risk of GI illness for each beach and both beaches combined. In these models, contrasts were created to show ORs of a unit increase in exposure among swimmers. At both beaches, we observed a trend between increasing mean [log.sub.10] QPCRCE of Enterococcus and risk of GI illness.
We observed a slightly stronger association with GI illness for the overall daily average of Enterococcus QPCRCE than for averages specific to a beachgoer's reported swimming location. At beach A, a [log.sub.10] increase in the daily average of Enterococcus QPCRCE was associated with a 1.43 (95% CI, 1.08-1.90) increase in the odds of GI illness for those immersing their bodies. At beach B, estimates for trends between GI illness and Enterococcus QPCRCE daily averages were also elevated but slightly lower.
Bacteroides QPCRCE was positively associated with illness at beach B, but trends were of borderline statistical significance (p < 0.1). Again, we found little difference between the overall daily average and averages based on a beachgoer's reported swimming location. No association was observed between Bacteroides QPCRCE and GI illness at beach A.
Trends tended to be stronger when we defined swimming as body or head immersion than when we defined swimming as any contact with water. Defining swimming as head immersion at beach B resulted in a weaker trend than did body immersion or any contact with water, but at this beach only 18% of respondents reported immersing their head.
We included an indicator for beach in the models that combined the results for both beaches. No trend between GI illness and Bacteroides QPCRCE was observed when both beaches are combined because of the lack of an observed trend at beach A. Trends between illness and daily averages of Enterococcus QPCRCE were statistically significant (p = 0.005). A [log.sub.l0] increase in Enterococcus QPCRCE was associated with a 1.37 (95% CI, 1.10-1.71) increase in the odds of GI illness. A likelihood ratio test comparing the saturated model In mathematical logic, and in particular model theory, a saturated model M is one which realizes as many complete types as may be "reasonably expected" given its size. with the restricted model indicated that the interaction between beach and daily averaged water-quality measure was not statistically significant (p = 0.48). The beach effect was statistically significant (AOR = 0.64; 95% CI, 0.52-0.73, beach B vs. beach A), reflecting the lower overall incidence of GI illness at beach A.
Figure 1 illustrates the predicted probabilities for GI illness as a function of the [log.sub.10] QPCRCE Enterococcus measures for swimmers immersing their bodies at both beaches combined.
[FIGURE 1 OMITTED]
We examined the 0800 hr samples separately to see if water samples tested in the morning were predictive of GI illness among swimmers that day. As shown in Table 3, Enterococcus QPCRCE measured at 0800 hr was associated with GI illness that day. Although the trends are not as strong as the daily or location-specific averages, Enterococcus QPCRCE measured at 0800 hr was predictive of GI illness that day, with a [log.sub.10] increase associated with an approximately 1.2 increase in the odds of GI illness.
The trend between increasing Enterococcus QPCRCE with illness was stronger among swimmers who spent more time in the water (Table 4). A [log.sub.10] increase in Enterococcus QPCRCE and GI illness among those spending > 2 hr in the water was associated with a nearly 3-fold increase in the odds of GI illness (AOR = 2.89; 95% CI, 1.55-5.40).
This is the first study to demonstrate the ability of rapid indicator methods to predict health effects. The results showed that Enterococcus measured by QPCR can predict GI illness after swimming in fecally contaminated fresh water. The results also demonstrate that samples collected each morning could allow beach managers to assess the microbiological safety of the beach before most beachgoers are exposed. Incorporation of rapid measurements such as these into a regulatory framework has the potential to improve beach management decisions and protect swimmers' health.
Swimmers at the two Great Lake beaches had a higher incidence of GI illness than did nonswimmers. Among swimmers at beach A, risk of illness increased as daily averages of Enterococcus QPCRCE increased. Among swimmers at beach B, daily averages of Enterococcus QPCRCE were also positively associated with GI illness, although the 95% CI of the OR included 1.0. This power to detect a significant effect at beach B may have been limited because of fewer swimmers at this beach. Combining beaches produced significant trends with both daily averages and averages of samples collected at 0800 hr only. The association between Enterococcus QPCRCE and GI illness strengthened as the time spent in water increased, possibly reflecting an increased risk of illness resulting from increased exposure to fecal contamination among those spending longer periods in the water.
Using QPCRCE averages specific to a beachgoer's reported swimming location did not improve the relationship between illness and water quality. This may be because swimmers swam in several locations and did not restrict their swimming along one transect tran·sect
tr.v. tran·sect·ed, tran·sect·ing, tran·sects
To divide by cutting transversely.
[trans- + -sect. . Also, recall or reporting errors in swimming location would lead to misclassification. As a result, the daily averages that combined results at each location, time, and water depth may have been a better characterization of the exposure of an average swimmer.
Results for Bacteroides QPCRCE were less promising, and interpretation of the results is limited because a relatively high proportion of samples were below the LOD. Although a borderline trend was noted at beach B, where fewer samples were below the LOD, no trend was observed at beach A. Imputing the censored values using one-half the LOD did not improve the relationship, nor did eliminating the censored data points. Efforts are being made to improve the sensitivity of the Bacteroides assay with the hope of improving its reliability as a predictor of illness. One of the advantages of the QPCR method is the ability to archive samples, and if improvements are made to the assay, they will be retested.
The two beaches differed with respect to swimming, demographic characteristics, and baseline illness. At beach B, more respondents were > 35 years of age (59% vs. 39%) and white (90% vs. 73%) than at beach A. A higher proportion of nonswimmers at beach B reported illness than at beach A (10% vs. 5%). Differences in the study populations may have been responsible for the higher overall risk in illness among swimmers compared with non-swimmers at beach A.
We observed no striking difference in the trend between illness and water quality for the different types of swimming definitions. With the exception of Enterococcus at the Lake Erie beach (beach B), trends tended to be stronger when swimming was defined as body immersion and head immersion compared with any contact with water. This is consistent with the hypothesis that more active types of swimming would result in greater exposure to fecally contaminated water.
Because trends were evaluated among swimmers, it is unlikely that the observed associations could be attributed to unmeasured confounding confounding
when the effects of two, or more, processes on results cannot be separated, the results are said to be confounded, a cause of bias in disease studies.
confounding factor factors. It is unlikely that swimmers associated themselves with different water quality with respect to characteristics that could affect GI illness. Adjusting for covariates tended to strengthen the trend and association between illness and water quality.
Although we selected beaches affected by human fecal contamination, we do not know whether fecal contamination from other bathers was an important contributor to the overall level of fecal contamination. Although there was no significant difference in Enterococcus QPCRCE by collection time, the average QPCRCE increased slightly throughout the day, suggesting that swimmers may have contributed some fecal contamination.
Because QPCR relies on DNA to quantify organisms, viable organisms are not necessary for measurement. As a result, indicators measured by QPCR may differ in their sensitivity to some environmental conditions. For example, we did not see a reduction in QPCRCE over the course of the day, an effect that has been observed for culture-based indicator organisms resulting from die-off caused by ultraviolet radiation (Whitman et al. 2004). There is a need for additional studies to better understand how indicators measured by QPCR are affected by physical and environmental factors in recreational waters.
Because this is the first and only study to evaluate the ability of rapid water-quality indicators to predict GI illness, additional studies will be required to evaluate the generalizability of these findings. Additional studies and analyses will help determine whether these preliminary findings are consistent and robust enough from a regulatory perspective to recommend a rapid indicator for recreational water quality, and to evaluate the conditions under which such indicators can successfully be applied. Ultimately, the use of faster indicators of recreational water quality will result in the ability to make decisions about recreational water quality on the day of sample collection. This, in turn, could lower GI illnesses in communities, especially in those dependent on beach-related tourism.
We thank R. Haugland, L. Wymer, J. Hansel han·sel
n. & v.
Variant of handsel. , K. DeLa Torre, K. Patrizi, R. Clickner, and the NEEAR team; R. Whitman; C. Hoffman; Indiana Dunes Indiana Dunes
State park and national lakeshore, southern shore of Lake Michigan, northern Indiana, U.S. The state park (founded 1925) comprises 2,182 acres (883 hectares) of shoreline, marshland, dunes, and forests. National Park; Cleveland Metroparks The Cleveland Metroparks, one of several Ohio Metroparks, are a system of nature preserves in Greater Cleveland that encircle the city of Cleveland. These generally follow the rivers that flow through the region to Lake Erie. ; and the Cuyahoga County Board of Health for their assistance.
Alexander LM, Heaven A, Tennant A, Morris R. 1992. Symptomatology symptomatology /symp·to·ma·tol·o·gy/ (simp?to-mah-tol´ah-je)
1. the branch of medicine dealing with symptoms.
2. the combined symptoms of a disease.
n. of children in contact with sea water contaminated with sewage. J Epidemiol Community Health 46(4):340-344.
Applied Biosystems. 1997. User Bulletin #2: ABI Abi (ā`bī) [short for Abijah], in the Bible, King Hezekiah's mother.
(Application Binary Interface) A specification for a specific hardware platform combined with the operating system. PRISM 7700 Sequence Detection System. Foster City, CA:Applied Biosystems Corporation.
Beaches Environmental Assessment and Coastal Health Act. 2000. Public Law 106-284. Available: http://www.epa.gov/ost/beaches/ beachbill.pdf [accessed 16 November 2005].
Boehm AB, Grant SB, Kim JH, Mowbray SL, McGee CD, Clark CD, et al. 2002. Decadal and shorter period variability of surf zone surf zone
See breaker zone.
See breaker zone.
The area of water from the surf line to the beach. See also surf line. water quality at Huntington Beach, California Huntington Beach is a seaside city in Orange County in southern California. As of the 2000 census, the city population was 189,594. It is bordered by the Pacific Ocean on the west, by Seal Beach on the north, by Costa Mesa on the south, by Westminster on the northeast, and by . Environ Sci Technol 36(18):3885-3892.
Cabelli V, Dufour A, Levin M, Habermann P. 1975. The impact of pollution on marine bathing beaches: an epidemiological study An Epidemiological study is a statistical study on human populations, which attempts to link human health effects to a specified cause. . In: Middle Atlantic Adj. 1. middle Atlantic - of a region of the United States generally including Delaware; Maryland; Virginia; and usually New York; Pennsylvania; New Jersey; "mid-Atlantic states"
mid-Atlantic Continental Shelf and the New York Bight The New York Bight is a large gulf on the Atlantic Ocean along the coast of North America in the northeastern United States. It is formed by the coastal identation between New Jersey and Long Island around the mouth of the Hudson River at New York Harbor. : Proceedings of the Symposium, American Society of Limnology limnology
Subdiscipline of hydrology that concerns the study of fresh waters, specifically lakes and ponds (both natural and manmade), including their biological, physical, and chemical aspects. and Oceanography oceanography, study of the seas and oceans. The major divisions of oceanography include the geological study of the ocean floor (see plate tectonics) and features; physical oceanography, which is concerned with the physical attributes of the ocean water, such as , 3-5 November 1975, New York City New York City: see New York, city.
New York City
City (pop., 2000: 8,008,278), southeastern New York, at the mouth of the Hudson River. The largest city in the U.S. , New York New York, state, United States
New York, Middle Atlantic state of the United States. It is bordered by Vermont, Massachusetts, Connecticut, and the Atlantic Ocean (E), New Jersey and Pennsylvania (S), Lakes Erie and Ontario and the Canadian province of . Lawrence, KS:American Society of Limnology and Oceanography, 424-432.
Cabelli VJ, Dufour AP, Levin MA, McCabe L J, Haberman PW. 1979. Relationship of microbial indicators to health effects at marine bathing beaches. Am J Public Health 69(7):690-696.
Cabelli VJ, Dufour AP, McCabe LJ, Levin MA. 1982. Swimming-associated gastroenteritis gastroenteritis: see enteritis.
Acute infectious syndrome of the stomach lining and intestines. Symptoms include diarrhea, vomiting, and abdominal cramps. and water quality. Am J Epidemiol 115(4):606-616.
Colford JM Jr, Rees JR, Wade T J, Khalakdina A, Hilton JF, Ergas IJ, et al. 2002. Participant blinding and gastrointestinal illness in a randomized ran·dom·ize
tr.v. ran·dom·ized, ran·dom·iz·ing, ran·dom·iz·es
To make random in arrangement, especially in order to control the variables in an experiment. , controlled trial controlled trial Clinical research A clinical study in which one group of participants receives an experimental drug while the other receives either a placebo or an approved–'gold standard' therapy. See Blinding, Double-blinded. of an in-home drinking water intervention. Emerg Infect Dis 8(1):29-36.
Dick LK, Field KG. 2004. Rapid estimation of numbers of fecal Bacteroidetes by use of a quantitative PCR assay for 16S rRNA genes. Appl Environ Microbiol 70(9):5695-5697.
Dorfman M. 2005. Testing the Waters: A Guide to Water Quality at Vacation Beaches. New York:Natural Resources Defense Council.
Dufour A. 1984. Health Effects Criteria for Fresh Recreational Waters. EPA-600-1-84-004. Cincinnati, OH:U.S. Environmental Protection Agency.
El-Shaarawi A. 1989. Inferences about the mean from censored water quality data. Water Resources Res 25(4):685-690.
El-Shaarawi A, Viveros R. 1997. Inference about the mean in log regression with environmental applications. Environmetrics 8:569-582.
El-Sharkawi F, Hassan MNER. 1982. The relation between the state of pollution on Alexandria swimming beaches and the occurrence of typhoid typhoid
or typhoid fever
Acute infectious disease resembling typhus (and distinguished from it only in the 19th century). Salmonella typhi, usually ingested in food or water, multiplies in the intestinal wall and then enters the bloodstream, causing among bathers. Buff High Inst Public Health Alexandria 12:337-351.
Fleisher JM, Kay D, Salmon RL, Jones F, Wyer MD, Godfree AF. 1996. Marine waters contaminated with domestic sewage: nonenteric illnesses associated with bather exposure in the United Kingdom. Am J Public Health 86(9):1228-1234.
Greenland S, Rothman KJ. 1998. Modern Epidemiology. Philadelphia:Lippincott-Raven.
Griffin OW, Donaldson KA, Paul JH, Rose JB. 2003. Pathogenic human viruses in coastal waters. Clin Microbiol Rev 16(1):129-143.
Haugland RA, Siefring SC, Wymer LJ, Brenner KP, Dufour AP. 2005. Comparison of Enterococcus measurements in freshwater at two recreational beaches by quantitative polymerase chain reaction and membrane filter culture analysis. Water Res 39(4):559-568.
Insightful Corp. 2002. S-PLUS Professional Edition, Version 6.1 for Microsoft Windows See Windows.
(operating system) Microsoft Windows - Microsoft's proprietary window system and user interface software released in 1985 to run on top of MS-DOS. Widely criticised for being too slow (hence "Windoze", "Microsloth Windows") on the machines available then. . Seattle, WA:Insightful Corp.
Jones K. 2001. Campylobacters in water, sewage and the environment. J Appl Microbiol 90(s6):68S-79S.
Khuder SA, Arthur T, Bisesi MS, Schaub EA. 1998. Prevalence of infectious diseases infectious diseases: see communicable diseases. and associated symptoms in wastewater treatment workers. Am J Ind Med 33(6):571-577.
Kim JH, Grant SB. 2004. Public mis-notification of coastal water quality: a probabilistic (probability) probabilistic - Relating to, or governed by, probability. The behaviour of a probabilistic system cannot be predicted exactly but the probability of certain behaviours is known. Such systems may be simulated using pseudorandom numbers. evaluation of posting errors at Huntington Beach, California. Environ Sci Technol 38(9):2497-2504.
Lee SH, Levy DA, Craun GF, Beach MJ, Calderon RL. 2002. Surveillance for waterborne disease outbreaks--United States, 1999-2000. MMWR MMWR Morbidity & Mortality Weekly Report Epidemiology A news bulletin published by the CDC, which provides epidemiologic data–eg, statistics on the incidence of AIDS, rabies, rubella, STDs and other communicable diseases, causes of mortality–eg, Surveill Summ 51(8):1-47.
Mac Kenzie WR, Hoxie NJ, Proctor ME, Gradus GRADUS. This is a Latin word, literally signifying a step; figuratively it is used to designate a person in the ascending or descending line, in genealogy; a degree. MS, Blair KA, Peterson DE, et al. 1994. A massive outbreak in Milwaukee of Cryptosporidium cryptosporidium (krĭp'tōspərĭd`ēəm), genus of protozoans having at least four species; they are waterborne parasites that cause the disease cryptosporidiosis. infection transmitted through the public water supply. N Engl J Med 331(3):161-167.
Medore MS, Rose JB, Gerba CP, Arrowood M J, Sterling CR. 1987. Occurrence of Cryptosporidium oocysts in sewage effluents and selected surface waters. J Parasitol 73(4):702-705.
National Survey on Recreation and the Environment (NSRE NSRE National Survey on Recreation and the Environment
NSRE North South Real Estate (Brisbane, Australia)
NSRE Nach's SNES ROM Tools ): 2000-2002. The Interagency in·ter·a·gen·cy
Involving or representing two or more agencies, especially government agencies. National Survey Consortium, Coordinated by the USDA USDA,
n.pr See United States Department of Agriculture. Forest Service, Recreation, Wilderness, and Demographics Trends Research Group, Athens, GA and the Human Dimensions Research Laboratory. Knoxville, TN:University of Tennessee The University of Tennessee (UT), sometimes called the University of Tennessee at Knoxville (UT Knoxville or UTK), is the flagship institution of the statewide land-grant University of Tennessee public university system in the American state of Tennessee. .
Noble RT, Weisberg SB, Leecaster MK, McGee CO, Ritter rit·ter
n. pl. ritter
[German, from Middle High German riter, from Middle Dutch ridder, from r K, Walker KO, et al. 2003. Comparison of beach bacterial water quality indicator measurement methods. Environ Monit Assess 81:301-312.
Payment P, Richardson L, Siemiatycki J, Dewar R, Edwardes M, Franco E. 1991. A randomized trial to evaluate the risk of gastrointestinal disease due to consumption of drinking water meeting current microbiological standards. Am J Public Health 81(6):703-708.
Payment P, Siemiatycki J, Richardson L, Gilles R, Franco E, Prevost M. 1997. A prospective epidemiological study of gastrointestinal health effects due to the consumption of drinking water. Int J Environ Health Res7:5-31.
Pruss A. 1998. Review of epidemiological studies on health effects from exposure to recreational water. Int J Epidemiol 27(1):1-9.
Santo Domingo JW, Siefring SC, Haugland RA. 2003. Real-time PCR method to detect Enterococcus faecalis Enterococcus faecalis is a Gram-positive commensal bacterium inhabiting the gastrointestinal tracts of humans and other mammals. Like other species in the genus Enterococcus, E. in water. Biotechnol Lett 25(3):261-265.
SAS Institute. 2001. The SAS System (1) Originally called the "Statistical Analysis System," it is an integrated set of data management and decision support tools from SAS that runs on platforms from PCs to mainframes. for Windows, Version 8.0. Cary, NC: SAS Institute Inc.
StataCorp. 2005. Stata SE, Version 8.2. College Station, TX:StataCorp.
U.S. EPA. 2001. Report to Congress: Implementation and Enforcement of the Combined Sewer A combined sewer is a type of sewer system which provides partially separated channels for sanitary sewage and stormwater runoff. This allows the sanitary sewer system to provide backup capacity for the runoff sewer when runoff volumes are unusually high, but it is an antiquated Overflow Policy. EPA 833-R-01-003. Washington, DC:Environmental Protection Agency, Office of Water.
Wade TJ, Pal N, Eisenberg JN, Colford JMJ JMJ Jam Master Jay (rap artist)
JMJ Jornada Mundial de la Juventud
JMJ Jean Michel Jarre (musician)
JMJ Jesus-Mary-Joseph . 2003. Do U.S. Environmental Protection Agency water quality guidelines for recreational waters prevent gastrointestinal illness? A systematic review and meta-analysis. Environ Health Perspect 111:1102-1109.
Whitman RL, Nevers MB, Ginger C, Korinek, Byappanahalli MN. 2004. Solar and temporal effects on Escherichia coil concentration at a Lake Michigan swimming beach. Environ Sci Technol 70(7):4276-4285.
Yamamoto N, Urabe K, Takaoka M, Nakazawa K, Gotoh A, Haga M, et al. 2000. Outbreak of cryptosporidiusis after contamination of the public water supply in Saitama Prefecture Saitama Prefecture (埼玉県 Saitama-ken , Japan, in 1996. Kansenshogaku Zasshi 74(6):519-526.
This study was funded by the U.S. EPA and managed by Westat Corp. (contract 68-D-02-062).
The information in this document has been subjected to review by the National Health and Environmental Effects Research Laboratory and approved for publication. Approval does not signify that the contents reflect the views of the agency.
The authors declare they have no competing financial interests.
Received 2 May 2005; accepted 1 September 2005.
Timothy J. Wade, (7) Rebecca L. Calderon, (1) Elizabeth Sams, (1) Michael Beach Michael Anthony Beach (born October 30, 1963) is an American actor.
Beach was born in Boston, Massachusetts, of Cape Verdean descent. He attended the prestigious Noble & Greenough School in Dedham, Massachusetts on scholarship from ABC (A Better Chance). ,(2) Kristen P. Brenner, (3) Ann H. Williams, (1) and Alfred P. Dufour (3)
(1) National Health and Environmental Effects Research Laboratory, Human Studies Division, U.S. Environmental Protection Agency, Research Triangle Park Research Triangle Park, research, business, medical, and educational complex situated in central North Carolina. It has an area of 6,900 acres (2,795 hectares) and is 8 × 2 mi (13 × 3 km) in size. Named for the triangle formed by Duke Univ. , North Carolina North Carolina, state in the SE United States. It is bordered by the Atlantic Ocean (E), South Carolina and Georgia (S), Tennessee (W), and Virginia (N). Facts and Figures
Area, 52,586 sq mi (136,198 sq km). Pop. , USA; (2) parasitic Diseases, Centers for Disease Control and Prevention, Atlanta, Georgia, USA; (3) National Exposure Research Laboratory, U.S. Environmental Protection Agency, Cincinnati, Ohio “Cincinnati” redirects here. For other uses, see Cincinnati (disambiguation).
Cincinnati is a city in the U.S. state of Ohio and the county seat of Hamilton County. , USA
Address correspondence to R.L. Calderon, U.S. EPA Human Studies Division, MD 58A, Research Triangle Park, NC 27711 USA. Telephone: (919) 966-0617. Fax: (919) 966-6212. E-mail: Calderon.email@example.com
Table 1. Summary statistics for [log.sub.10] indicator organisms, measured by QPCR. Enterococcus (a) Beach A Beach B No. of days 20 13 No. of samples 329 350 QPCRCE/100 mL Mean 2.04 1.90 Median 2.07 2.05 SD 0.97 1.03 Minimum/maximum -1.53/4.20 -1.75/4.17 No. (%) < LOD 9 (2.74) 11 (3.14) Bacteroides (b) Beach A Beach B No. of days 20 13 No. of samples 329 350 QPCRCE/100 mL Mean 3.08 3.02 Median 3.34 3.63 SD 1.12 1.56 Minimum/maximum 0.97/5.37 -0.23/5.57 No. (%) < LOD 91 (27.66) 74 (21.14) (a) p=0.06 for difference in log QPCRCE (t-test). (b) p = 0.55 for difference in log QPCRCE (t test). Table 2. GI illness among swimmers and nonswimmers. No. reporting GI No. (% of illness (% total) of exposed) AOR (95% CI) Beach A No contact with water 722 (25) 36 (5.0) Any contact with water 2,154 (75) 208 (9.7) 1.96 (1.33-2.90) * Body immersion 1,667 (58) 169 (10) 2.26 (1.51-3.39) * Head immersion 1,210 (42) 117 (9.7) 2.14 (1.41-3.27) * Total respondents 2,876 (a) Beach B No contact with water 1,535 (54) 147 (10) Any contact with water 1,305 (46) 159 (12) 1.27 (0.97- 1.67) ** Body immersion 757 (27) 101 (13) 1.45 (1.06-1.98) * Head immersion 524 (18) 71 (14) 1.50 (1.06-2.13) * Total respondents 2,840 Both beaches No contact with water 183 (8) Any contact with water 367 (11) 1.45 (1.17-1.80) * Body immersion 270 (11) 1.63 (1.29-2.07) * Head immersion 188 (11) 1.61 (1.25-2.07) * (a) One missing value. * p < 0.05. ** p < 0.1. Table 3. AORs (95% Cls) for a 1 [log.sub.10] increase in Enterococcus QPCRCE and GI illness. (a) Enterococcus QPCRCE Average by day and Exposure Average by day location of swimming Beach A Any contact 1.36 * (1.05-1.76) 1.32 * (1.04-1.67) Body immersion 1.43 * (1.08-1.90) 1.34 * (1.03-1.74) Head immersion 1.49 * (1.07-2.08) 1.41 * (1.04-1.90) Beach B Any contact 1.25 (0.93-1.67) 1.20 (0.87-1.66) Body immersion 1.38 ** (0.94-2.01) 1.27 (0.90-1.81) Head immersion 1.17 (0.76-1.82) 1.15 (0.77-1.71) Beaches A and B combined Any contact 1.30 * (1.08-1.57) 1.25 * (1.05-1.49) Body immersion 1.37 * (1.10-1.71) 1.26 (1.04-1.53) Head immersion 1.35 * (1.05-1.75) 1.29 * (1.03-1.63) Enterococcus QPCRCE Bacteroides QPCRCE Average Exposure 0800-hr sample Average by day Beach A Any contact -- 0.89 (0.75-1.06) Body immersion -- 0.89 (0.74-1.07) Head immersion -- 0.84 (0.67-1.05) Beach B Any contact -- 1.15 (0.94-1.41) Body immersion -- 1.24 ** (0.96-1.60) Head immersion -- 1.28 ** (0.95-1.73) Beaches A and B combined Any contact 1.18 * (1.03-1.34) 0.99 (0.87-1.13) Body immersion 1.21 * (1.04-1.40) 1.00 (0.86-1.16) Head immersion 1.21 * (1.02-1.44) 0.99 (0.83-1.17) Bacteroides QPCRCE Average by day and Average Exposure location of swimming 0800-hr sample Beach A Any contact 0.87 (0.74-1.02) -- Body immersion 0.87 (0.73-1.04) -- Head immersion 0.87 (0.37-1.17) -- Beach B Any contact 1.12 ** (0.97-1.31) -- Body immersion 1.17 ** (0.97-1.40) -- Head immersion 1.20 * (0.97-1.49) -- Beaches A and B combined Any contact 1.01 (0.90-1.12) 0.95 (0.86-1.05) Body immersion 1.01 (0.89-1.14) 0.94 (0.84-1.06) Head immersion 1.00 (0.86-1.15) 0.92 (0.80-1.06) (a) ORs estimated from multivariate logistic regression of GI illness on the log (base 10) indicator measure. * p < 0.05. ** p < 0.1. Table 4. AORs (95% Cls) for a 1 [log.sub.10] increase in the daily average of Enterococcus OPCRCE and GI illness among swimmers by time spent in water, beaches A and B combined. (a) Time spent AOR per 1 [log.sub.10] in water (min) No. increase (95% CI) [greater than or equal to] 15 2,477 1.45 (1.14-1.85) * [greater than or equal to] 30 1,572 1.48 (1.12-1.96) * [greater than or equal to] 60 735 1.84 (1.25-2.72) * [greater than or equal to] 120 289 2.89 (1.55-5.40) * (a) Body immersed in water. * p < 0.05.