Recreational Water Exposure Research Articles

Vital Signs: Drowning Death Rates, Self-Reported Swimming Skill, Swimming Lesson Participation, and Recreational Water Exposure — United States, 2019–2023

<i>Vital Signs</i>: Drowning Death Rates, Self-Reported Swimming Skill, Swimming Lesson Participation, and Recreational Water Exposure — United States, 2019–2023

A one health approach for monitoring antimicrobial resistance: developing a national freshwater pilot effort.

Antimicrobial resistance (AMR) is a world-wide public health threat that is projected to lead to 10 million annual deaths globally by 2050. The AMR public health issue has led to the development of action plans to combat AMR, including improved antimicrobial stewardship, development of new antimicrobials, and advanced monitoring. The National Antimicrobial Resistance Monitoring System (NARMS) led by the United States (U.S) Food and Drug Administration along with the U.S. Centers for Disease Control and U.S. Department of Agriculture has monitored antimicrobial resistant bacteria in retail meats, humans, and food animals since the mid 1990's. NARMS is currently exploring an integrated One Health monitoring model recognizing that human, animal, plant, and environmental systems are linked to public health. Since 2020, the U.S. Environmental Protection Agency has led an interagency NARMS environmental working group (EWG) to implement a surface water AMR monitoring program (SWAM) at watershed and national scales. The NARMS EWG divided the development of the environmental monitoring effort into five areas: (i) defining objectives and questions, (ii) designing study/sampling design, (iii) selecting AMR indicators, (iv) establishing analytical methods, and (v) developing data management/analytics/metadata plans. For each of these areas, the consensus among the scientific community and literature was reviewed and carefully considered prior to the development of this environmental monitoring program. The data produced from the SWAM effort will help develop robust surface water monitoring programs with the goal of assessing public health risks associated with AMR pathogens in surface water (e.g., recreational water exposures), provide a comprehensive picture of how resistant strains are related spatially and temporally within a watershed, and help assess how anthropogenic drivers and intervention strategies impact the transmission of AMR within human, animal, and environmental systems.

Estimating Waterborne Infectious Disease Burden by Exposure Route, United States, 2014.

More than 7.15 million cases of domestically acquired infectious waterborne illnesses occurred in the United States in 2014, causing 120,000 hospitalizations and 6,600 deaths. We estimated disease incidence for 17 pathogens according to recreational, drinking, and nonrecreational nondrinking (NRND) water exposure routes by using previously published estimates. In 2014, a total of 5.61 million (95% credible interval [CrI] 2.97-9.00 million) illnesses were linked to recreational water, 1.13 million (95% CrI 255,000-3.54 million) to drinking water, and 407,000 (95% CrI 72,800-1.29 million) to NRND water. Recreational water exposure was responsible for 36%, drinking water for 40%, and NRND water for 24% of hospitalizations from waterborne illnesses. Most direct costs were associated with pathogens found in biofilms. Estimating disease burden by water exposure route helps direct prevention activities. For each exposure route, water management programs are needed to control biofilm-associated pathogen growth; public health programs are needed to prevent biofilm-associated diseases.

Recreational water exposures and illness outcomes at a freshwater beach in Toronto, Canada: A prospective cohort pilot study.

Swimming and other recreational water activities in surface waters are popular in Canada during the summer. However, these activities can also increase the risk of recreational water illness. While routine monitoring of beach water quality is conducted by local authorities each summer, little research is available in Canada about beach exposures and illness risks. We conducted a pilot of a prospective cohort study at a popular beach in Toronto, Ontario, Canada, in 2022 to determine characteristics of beachgoers, common water and sand exposures, the incidence of recreational water illness, and the feasibility for a larger, national cohort study. We enrolled beachgoers on-site and surveyed about their exposures at the beach and conducted a follow-up survey 7 days following their beach visit to ascertain acute gastrointestinal, respiratory, skin, ear, and eye illness outcomes. We descriptively tabulated and summarized the collected data. We enrolled 649 households, consisting of 831 beachgoers. Water contact activities were reported by 56% of beachgoers, with swimming being the most common activity (44% of participants). Similarly, 56% of beachgoers reported digging in the sand or burying themselves in the sand. Children (≤14 years) and teenagers (15-19 years) were most likely to report engaging in water contact activities and swallowing water, while children were most likely to report sand contact activities and getting sand in their mouth. Boys and men were more likely than women and girls to report swallowing water (15.2% vs. 9.4%). Water and sand exposures also differed by household education level and participant ethno-racial identity. E. coli levels in beach water were consistently low (median = 20 CFU/100 mL, range = 10-58). The incidence of illness outcomes was very low (0.3-2.8%) among the 287 participants that completed the follow-up survey. The identified beach exposure patterns can inform future risk assessments and communication strategies. Excellent water quality was observed at the studied beach, likely contributing to the low incidence of illnesses. A larger, national cohort study is needed in Canada to examine risks of illness at beaches at higher risk of fecal contamination.

Molecular Epidemiology of Antimicrobial Resistance and Virulence Profiles of Escherichia coli, Salmonella spp., and Vibrio spp. Isolated from Coastal Seawater for Aquaculture.

The occurrence of waterborne antimicrobial-resistant (AMR) bacteria in areas of high-density oyster cultivation is an ongoing environmental and public health threat given the popularity of shellfish consumption, water-related human recreation throughout coastal Thailand, and the geographical expansion of Thailand's shellfish industry. This study characterized the association of phenotypic and genotypic AMR, including extended-spectrum β-lactamase (ESBL) production, and virulence genes isolated from waterborne Escherichia coli (E. coli) (n = 84), Salmonella enterica (S. enterica) subsp. enterica (n = 12), Vibrio parahaemolyticus (V. parahaemolyticus) (n = 249), and Vibrio cholerae (V. cholerae) (n = 39) from Thailand's coastal aquaculture regions. All Salmonella (100.0%) and half of V. cholerae (51.3%) isolates harbored their unique virulence gene, invA and ompW, respectively. The majority of isolates of V. parahaemolyticus and E. coli, ~25% of S. enterica subsp. enterica, and ~12% of V. cholerae, exhibited phenotypic AMR to multiple antimicrobials, with 8.9% of all coastal water isolates exhibiting multidrug resistance (MDR). Taken together, we recommend that coastal water quality surveillance programs include monitoring for bacterial AMR for food safety and recreational water exposure to water for Thailand's coastal water resources.

Occurrence of coliphage in effluent: A systematic literature review and meta-analysis

Studies have illustrated that wastewater treatment methods targeting bacteria do not remove all types of viruses and available epidemiological studies indicate bacteria concentrations may not always be predictive of viral illnesses associated with recreational water exposure. To address these challenges, coliphages have been proposed as an indicator of fecal contamination in recreational water. When compared to traditional fecal indicator bacteria, coliphages exhibit a longer persistence in the environment. The persistence of coliphages in the environment and through wastewater treatment more closely resembles that of pathogenic viruses. We conducted a systematic literature search of peer-reviewed publications to identify coliphage density data (somatic [SC] and male-specific [MSC]) in wastewater treatment plant (WWTP) effluent categorized as primary, secondary, tertiary treated, or disinfected. Scope, study quality, and data availability were included as literature review inclusion criteria. An analysis was conducted to estimate the coliphage densities for specific treatment types within each respective WWTP effluent category. Densities of MSC and SC in influent were significantly higher when compared to densities of MSC and SC in effluent subjected to secondary treatment using biological treatment processes both with and without nutrient removal, tertiary treatment using either a treatment pond or a phosphate removal process, or disinfection using either chlorine, UV, or a combination of both UV and chlorine. Distributions of coliphage in various wastewater effluents will be useful for evaluating the efficacy of treatment processes and disinfectants in future microbial risk assessments.

Recreational water exposure and waterborne infections in a prospective salivary antibody study at a Lake Michigan beach

In a prospective observational study, seroconversion to a specific pathogen can serve as a marker of an incident infection, whether or not that infection is symptomatic or clinically diagnosed. While self-reported symptoms can be affected by reporting bias, seroconversion is likely to be free of this bias as it is based on objective measurements of antibody response. Non-invasive salivary antibody tests can be used instead of serum tests to detect seroconversions in prospective studies. In the present study, individuals and families were recruited at a Lake Michigan beach in Wisconsin in August 2011. Data on recreational water exposure and baseline saliva samples (S1) were collected at recruitment. Follow-up data on gastrointestinal symptoms were collected via a telephone interview approximately 10 days post-recruitment. Follow-up saliva samples were self-collected approximately 2 weeks (S2) and 30–40 days post-recruitment (S3) and mailed to the study laboratory. Samples were analyzed for immunoglobulin (Ig) G responses to recombinant antigens of three noroviruses and Cryptosporidium, as well as protein purification tags as internal controls, using an in-house multiplex suspension immunoassay on the Luminex platform. Responses were defined as ratios of antibody reactivities with a target protein and its purification tag. Seroconversions were defined as at least four-fold and three-fold increases in responses in S2 and S3 samples compared to S1, respectively. In addition, an S2 response had to be above the upper 90% one-sided prediction limit of a corresponding spline function of age. Among 872 study participants, there were seven (0.8%) individuals with seroconversions, including six individuals with seroconversions to noroviruses and two to Cryptosporidium (one individual seroconverted to both pathogens). Among 176 (20%) individuals who reported swallowing lake water, there were six (3.4%) seroconversions compared to one (0.14%) seroconversion among the remaining 696 individuals: the crude and age-standardized risk differences per 1000 beachgoers were 32.7 (95% confidence limits 5.7; 59.6) and 94.8 (4.6; 276), respectively. The age-adjusted odds ratio of seroconversion in those who swallowed water vs. all others was 49.5 (4.5; 549), p = 0.001. Individuals with a norovirus seroconversion were more likely to experience vomiting symptoms within 4 days of the index beach visit than non-converters with an odds ratio of 34 (3.4, 350), p = 0.003. This study contributed further evidence that recreational water exposure is associated with symptomatic and asymptomatic waterborne infections, and that salivary antibody assays can be used in epidemiological surveys of norovirus and Cryptosporidium infections.

Death From Primary Amebic Meningoencephalitis After Recreational Water Exposure During Recent Travel to India-Santa Clara County, California, 2020.

In February 2020, a man returned to the United States after an 11-day trip to India and died of primary amebic meningoencephalitis (PAM), caused by nasal exposure to the free-living ameba Naegleria fowleri found in warm water. We identified potential exposures, confirmed etiology, and described the molecular epidemiology of the infection. We reviewed medical records to describe his clinical course and interviewed his family to determine water exposures. Genotyping was performed on the N. fowleri strain and compared with North American strains through repetitive nonpolymorphic nuclear loci analysis to identify differences. We reviewed N. fowleri strains in the National Center for Biotechnology Information database (GenBank) to determine genotypes present in India. The patient became acutely encephalopathic 3 days after returning; the only known nasal water exposure was at an indoor swimming pool in India 5 days earlier. Cerebrospinal fluid (CSF) testing demonstrated neutrophil-predominant pleocytosis and low glucose, but negative gram stain and culture. CSF microscopy revealed trophozoites; N. fowleri was detected by real-time polymerase chain reaction. Classical genotyping confirmed genotype I, common in the United States and among Indian strains in GenBank. The North American N. fowleri strains and the patient's strain varied at 5 nonpolymorphic loci. A man died from PAM after likely exposure at a vacation rental pool in India. We recommend including PAM in the differential diagnosis when CSF studies suggest bacterial meningitis but gram stain is negative. Genotyping can advance our understanding of N. fowleri molecular epidemiology and support future investigations.

Outbreaks associated with treated recreational water — United States, 2015–2019

This article describes 208 outbreaks associated with recreational water exposures in the U.S., the majority of which were due to either Cryptosporidium or Legionella infections and were primarily reported after exposure to public (i.e., nonbackyard) recreational water. These outbreaks resulted in 3646 cases of illness, 286 hospitalizations, and 13 deaths; all deaths were due to Legionella infection. Most outbreaks began between June and August each year, suggesting that solid organ transplant candidates and recipients should be mindful of the risks associated with public recreational water, particularly during the summer months.

Geographic Range of Recreational Water-Associated Primary Amebic Meningoencephalitis, United States, 1978-2018.

Naegleria fowleri is a free-living ameba that causes primary amebic meningoencephalitis (PAM), a rare but usually fatal disease. We analyzed trends in recreational water exposures associated with PAM cases reported during 1978–2018 in the United States. Although PAM incidence remained stable, the geographic range of exposure locations expanded northward.

Recreational water exposure is associated with asymptomatic and symptomatic salivary antibody immunoconversions to waterborne pathogens

Non-invasive salivary antibody tests can be used to detect symptomatic and asymptomatic waterborne infections in prospective studies. Immunoconversion as a marker of infection is free of reporting bias potentially affecting self-reported symptoms. Families with children (875 individuals) were recruited at a Lake Michigan beach in Wisconsin in summer 2011. Data on recreational water exposure and baseline saliva samples (S1) were collected at recruitment. Follow-up saliva samples were self-collected at 10-14 days (S2) and 30-40 days post-recruitment (S3). Samples were analyzed for IgG responses to recombinant antigens of six noroviruses and Cryptosporidium, and control antigens using an in-house multiplex suspension immunoassay. Immunoconversions were defined as at least four-fold and three-fold increases in antibody responses in S2 and S3 samples compared to S1, with S2 responses to noroviruses and Cryptosporidium above the upper 80% or 90% one-sided prediction limits of spline functions of age, respectively. There were 8 (0.9%) immunoconversions including 7 immunoconversions to noroviruses. Among 176 individuals who reported swallowing lake water there were 5 (2.8%) immunoconversions compared to 3 (0.4%) immunoconversions in the remaining 699 individuals: odds ratio 14 (2.4; 80), p=0.004 after adjusting for age. Individuals with norovirus immunoconversion were more likely to experience vomiting or nausea symptoms within four days of the baseline beach visit than non-converters: age-adjusted odds ratios 34 (3.2; 355), p=0.003, for vomiting, and 8.8 (1.0; 77), p=0.05, for nausea. This study provided further evidence that recreational water exposure is associated with symptomatic and asymptomatic waterborne infections. This abstract does not represent EPA policy.

Alterations of the human skin microbiome after ocean water exposure

Skin is the body's first line of defense against invading microorganisms. The skin microbiome has been shown to provide immunity against exogenous bacterial colonization. Recreational water exposures may alter the skin microbiome and potentially induce skin infections. This study explored the link between ocean water exposures and the human skin microbiome. Skin microbiome samples were collected, using swabs, from human participants' calves before and after they swam in the ocean, and at 6 hour and 24 hour post-swim. Genomic analysis showed that skin microbiomes were different among individuals before swimming. But after swimming, microbial communities were no longer different, which was demonstrated by a decrease in inter-sample diversity. Taxonomic analysis showed that ocean bacteria, including potential pathogens, replaced the native skin bacteria and remained on the skin for at least 24 hour post-swim. This research provides insight into the relationship between the human skin microbiome and the environment.

First Cryptosporidium outbreak in Hungary, linked to a treated recreational water venue in 2015.

In June 2015, an outbreak of cryptosporidiosis with 35 cases (23 probable and 12 laboratory-confirmed) occurred among 191 attendees of a residential rehabilitation holiday for paediatric organ transplant patients (n = 49) and their families at a hotel in Somogy county, Hungary. The overall attack rate was 18%. Most of the cases were transplanted children who experienced severe acute disease and required adjustment to their tacrolimus immunosuppression. A retrospective case-control study suggested an association between recreational water exposures and illness: cases were seven times more likely than controls to have swum in the children's pool (odds ratio 7.17; 95% confidence interval 2.9-17.2; P < 0.0001) and five times more likely to have used the jetted whirlpool (odds ratio 5.25; 95% confidence interval 2.1-13.1; P < 0.0001). This was the first outbreak of cryptosporidiosis in Hungary and it is especially unfortunate that it affected vulnerable children who experienced severe symptoms. Cryptosporidium presents specific infection control difficulties in treated recreational water venues; the link to a whirlpool is unusual and highlights the importance of the age-appropriate use of these facilities and reminding users not to immerse their heads or swallow the water. Cryptosporidiosis is more commonly linked to children' pools where improved bather hygiene and promoting exclusion of diarrhoea cases could help to avoid similar outbreaks.

2057. Predictors for Gastrointestinal Protozoa Detection in U.S. Children Presenting with Acute Diarrhea

BackgroundThough more often associated with persistent diarrhea, protozoal gastroenteritis may also present as an acute illness. Suspicion for gastrointestinal protozoal infection is historically based on travel or recreational water exposure and duration of illness, which can delay diagnosis and effective treatment. The use of multiplex PCR panels has the potential to improve diagnosis of protozoal illness. To better understand when testing for protozoa is warranted, we examined predictors of protozoal gastroenteritis within a prospective multicenter study of U.S. children presenting to emergency departments with acute gastroenteritis (AGE).MethodsThe analysis utilized data from the IMPACT study, a prospective trial of the clinical impact of a multiplex PCR panel for detecting GI pathogens in AGE in five pediatric hospitals across the United States. From these data, we evaluated 72 potential predictors, including patient demographics, medical histories, exposures, symptoms, and vital signs. Using Random Forest Algorithm, 10 variables were selected based on variable importance measure. These were then entered into a Stepwise logistic regression model.ResultsOut of 962 patients there were 41 (4.3%) patients with protozoal detections, including 18 for Giardia and 24 for Cryptosporidium. Of these, 21 (51%) were male and the median age was 4.3 years old. Detection rates varied by site with 76% (31) of cases at two Midwestern sites. In 23 (56%) of cases protozoa was the sole pathogen detected. Logistic regression modeling of the top 10 variables identified by Random Forest showed the strongest predictor was living in a household with a child 5 years old or younger, followed by study site and younger age (table). Notably, travel, recreational water exposure, and duration of diarrhea were not in the top 10 variables identified. ConclusionOur analysis suggests that age and household exposure predict higher likelihood of protozoal infection in children with AGE. Classic epidemiologic exposures including travel and recreational water exposure were not predictive. These data could improve appropriate test selection. Future studies are still needed for external validation of this model.Disclosures A. Pavia, BioFire Dx: Investigator, Research support.

Simple and practical on-site treatment of high microcystin levels in water using polypropylene plastic

ABSTRACTMicrocystin (MC) is a hepatotoxin produced by various cyanobacteria during harmful algal blooms (HAB's) in freshwater environments. Advanced treatment methods can remove MC from drinking water, but are costly and do not address recreational water exposure and ecosystem health concerns. Here we investigate the feasibility of utilizing plastics as a MC-adsorbing material, for use in water resources used for recreation, agriculture, aquaculture and drinking water. Water containing 20 µg/L MC-LR was exposed to polypropylene (PP) plastic for a six-day period at varying temperatures (22, 37, 65°C). Water samples were then collected at 0, 1, 2, and 6 hour-intervals to examine short term treatment feasibility. Samples were also taken at 24 hours, 3 days, and 6 days to determine long-term treatment effectiveness. MC concentrations were analyzed using ELISA. Results showed a maximal reduction of nearly 70% of MC-LR after a 6-day treatment with PP at 65°C. Temperature enhanced MC-LR reduction over a 6-day period: 70% reduction at 65°C; 50% at 37°C; 38% at 22°C. We propose an inexpensive intervention strategy which can be deployed rapidly on-site in various source waters, including in resource-limited settings. During the high peak of HAB season, the strategy can be applied in source waters, alleviating water treatment burden for treatment plants, lowering treatment costs and reducing chemical usage.

Recognizing Recreational Water Exposure and Habituating HAB Surveillance in ESSENCE

Recognizing Recreational Water Exposure and Habituating HAB Surveillance in ESSENCE

Exploratory Assessment of Risks from Drinking and Recreational Water Exposure to Children in the State of New Jersey

In this study, we conducted a worst-case risk assessment for children’s health from ingestion exposure to water sources in two densely populated counties of the Piedmont province of New Jersey—Hunterdon and Mercer counties. Carcinogenic and non-carcinogenic health risk estimates for 19 contaminants, representing 3 different chemical classes—organic, inorganic and contaminants of emerging concern (CEC), for which environmental monitoring data are available—were generated. The three exposure scenarios examined were: (1) ingestion exposure to untreated groundwater from contaminated private wells; (2) recreational exposure through incidental ingestion of water from the Delaware River; and (3) ingestion exposure through fish consumption sourced from the Delaware River. The total health hazard posed by each contaminant across all the three exposure scenarios was compared to prioritize contaminants based on health risk potential. As a result of this analysis, arsenic and trichloroethylene in private well water were identified as key drivers of health risk and, hence, are proposed as the contaminants of primary concern for the target population. Significantly high total excess cancer risk of 2.13 × 10−3 from arsenic exposure was estimated, highlighting the need for testing and treating water sources as well as setting a framework for more detailed work in the future.

Drinking and recreational water exposures among Canadians: Foodbook Study 2014-2015.

In Canada, over 400,000 enteric diseases related to drinking water occur each year, highlighting the importance of understanding sources of Canadians' drinking and recreational water exposures. To address this need, a population-based telephone survey of 10,942 Canadians was conducted between 2014 and 2015, assessing Canadian's drinking water sources and recreational water exposures using a seven-day recall method. Results were analyzed by province/territory, season, age group, gender, income, education, and urban/rural status. Store-bought bottled water was reported by nearly 20% of survey respondents as their primary drinking water source, while approximately 11% of respondents reported private well. The proportion of private well users was significantly greater than the national average in the Maritime Provinces where approximately 40-56% of respondents reported this as their primary drinking water source. As expected, Canadians' recreational water activities and exposures (e.g., swimming, pool, lake, and waterpark) peaked during summer and were most commonly reported among children aged 0-9 years. Waterborne disease in Canada requires a multi-faceted public health approach. Canadian baseline data on water exposures can inform policy and public health strategies (e.g., recreational water guidelines, private well water testing recommendations) and support research and risk assessment related to mitigating waterborne illness.

Quantitative microbial risk assessment to estimate the health risk from exposure to noroviruses in polluted surface water in South Africa.

This study assessed the risks posed by noroviruses (NoVs) in surface water used for drinking, domestic, and recreational purposes in South Africa (SA), using a quantitative microbial risk assessment (QMRA) methodology that took a probabilistic approach coupling an exposure assessment with four dose-response models to account for uncertainty. Water samples from three rivers were found to be contaminated with NoV GI (80-1,900 gc/L) and GII (420-9,760 gc/L) leading to risk estimates that were lower for GI than GII. The volume of water consumed and the probabilities of infection were lower for domestic (2.91 × 10-8 to 5.19 × 10-1) than drinking water exposures (1.04 × 10-5 to 7.24 × 10-1). The annual probabilities of illness varied depending on the type of recreational water exposure with boating (3.91 × 10-6 to 5.43 × 10-1) and swimming (6.20 × 10-6 to 6.42 × 10-1) being slightly greater than playing next to/in the river (5.30 × 10-7 to 5.48 × 10-1). The QMRA was sensitive to the choice of dose-response model. The risk of NoV infection or illness from contaminated surface water is extremely high in SA, especially for lower socioeconomic individuals, but is similar to reported risks from limited international studies.

Burden of Disease Attributed to Waterborne Transmission of Selected Enteric Pathogens, Australia, 2010.

AbstractUniversal access to safe drinking water is a global priority. To estimate the annual disease burden of campylobacteriosis, nontyphoidal salmonellosis, cryptosporidiosis, giardiasis, and norovirus attributable to waterborne transmission in Australia, we multiplied regional World Health Organization (WHO) estimates of the proportion of cases attributable to waterborne transmission by estimates of all-source disease burden for each study pathogen. Norovirus was attributed as causing the most waterborne disease cases (479,632; 95% uncertainty interval [UI]: 0-1,111,874) followed by giardiasis and campylobacteriosis. The estimated waterborne disability-adjusted life year (DALY) burden for campylobacteriosis (2,004; 95% UI: 0-5,831) was 7-fold greater than other study pathogens and exceeded the WHO guidelines for drinking water quality (1 × 10-6 DALY per person per year) by 90-fold. However, these estimates include disease transmitted via either drinking or recreational water exposure. More precise country-specific and drinking water-specific attribution estimates would better define the health burden from drinking water and inform changes to treatment requirements.