Skin-related symptoms following exposure to recreational water: a systematic review and meta-analysis

Development of Multiplex RT qPCR Assays for Simultaneous Detection and Quantification of Faecal Indicator Bacteria in Bathing Recreational Waters

In this study, we designed and validated in silico and experimentally a rapid, sensitive, and specific multiplex RT qPCR for the detection and quantification of faecal indicator bacteria (FIB) used as microbiological references in marine bathing water regulations (Escherichia coli and intestinal enterococci). The 16S rRNA gene was used to quantify group-specific enterococci and Escherichia/Shigella and species-specific such as Enterococcus faecalis and E. faecium. Additionally, a ybbW gene encoding allantoin transporter protein was used to detect E. coli. An assessment of marine coastal systems (i.e., marine water and sediment) revealed that intestinal enterococci were the predominant group compared to Escherichia/Shigella. The low contribution of E. faecalis to the intestinal enterococci group was reported. As E. faecalis and E. faecium were reported at low concentrations, it is assumed that other enterococci of faecal origin are contributing to the high gene copy number of this group-specific enterococci. Moreover, low 16S rRNA gene copy numbers with respect to E. faecalis and E. faecium were reported in seawater compared to marine sediment. We conclude that marine sediments can affect the quantification of FIBs included in bathing water regulations. Valuing the quality of the marine coastal system through sediment monitoring is recommended.

Beachgoers' responses to beach health advisories

Drawing on responses from 238 beachgoers who have visited a Georgia (U.S. state) beach in the past three years, this study asks respondents about their knowledge of beach water quality monitoring, awareness of beach health advisories, perception of water quality, and expected responses upon learning of a beach's water pollution advisory. Binomial logistic regression finds that the only demographic predictor of respondents who would completely stop visiting a beach with an advisory is whether the respondent is a visitor or resident (year-round or part-time). Nearly 40% of visitors would not come to a beach with an advisory compared to 13.4% of residents. Most respondents report they would continue to visit a beach but would stay out of the water and stop harvesting seafood from the beach's waters. More than a third (36.1%), however, are unaware Georgia regularly monitors beach water for water quality, and 41.2% have never read a beach sign warning of contaminated water or seafood. Alarmingly, just over half view aesthetic factors such as no litter, no odor, and clear water as criteria for defining whether beach water is safe.

Multimodal analysis of south-eastern Black Sea sediment bacterial population diversity

This study focused on marine sediments from the Black Sea, mainly due to bacterial diversity-induced public health / biotechnology application value. Sediment samples were gathered from 14 locations at differing depths across Turkish shores on a seasonal basis over 10 months, with bacterial identifications performed through using multimodal analytical platforms. Overall, 26 differing, predominantly Gram-positive (57.5 %) bacterial species were identified for this region, including Bacillaceae (50.0 %) and Pseudomonadaceae (15.0 %). The most dominant classes were identified as Bacilli (52.5 %) and Gammaproteobacteria (40.0 %). Ten isolates (25 %) to the species level and thirty-six isolates (90 %) to the genus level were identified using VITEK® MS and Bruker Microflex® LT/SH, in comparison to 16S rRNA sequencing results. Identified species - particularly, novel reported species - can contribute to the knowledge of microbial life dwelling upon sediments of the south-eastern regions of the Black Sea.

Health risks to children from exposure to fecally-contaminated recreational water

Background

Children may be at higher risk for swimming-associated illness following exposure to fecally-contaminated recreational waters. We analyzed a pooled data set of over 80,000 beachgoers from 13 beach sites across the United States to compare risks associated with the fecal indicator bacteria Enterococcus spp. (measured by colony forming units, CFU and quantitative polymerase chain reaction cell equivalents, qPCR CE) for different age groups across different exposures, sites and health endpoints.

Methods

Sites were categorized according to the predominant type of fecal contamination (human or non-human). Swimming exposures of varying intensity were considered according to degree of contact and time spent in the water. Health endpoints included gastrointestinal and respiratory symptoms and skin rashes. Logistic regression models were used to analyze the risk of illness as a function of fecal contamination in water as measured by Enterococcus spp. among the exposed groups. Non-swimmers (those who did not enter the water) were excluded from the models to reduce bias and facilitate comparison across groups.

Results

Gastrointestinal symptoms were the most sensitive health endpoint and strongest associations were observed with Enterococcus qPCR CE at sites impacted by human fecal contamination. Under several exposure scenarios, associations between illness and Enterococcus spp. levels were significantly higher among children compared to adolescents and adults. Respiratory symptoms were also associated with Enterococcus spp. exposures among young children at sites affected by human fecal sources, although small sample sizes resulted in imprecise estimates for these associations.

Conclusion

Under many exposure scenarios, children were at higher risk of illness associated with exposure to fecal contamination as measured by the indicator bacteria Enterococcus spp. The source of fecal contamination and the intensity of swimming exposure were also important factors affecting the association between Enterococcus spp. and swimming-associated illness.

Carbapenem Resistance among Marine Bacteria-An Emerging Threat to the Global Health Sector

The emergence of antibiotic resistance among pathogenic microorganisms is a major issue for global public health, as it results in acute or chronic infections, debilitating diseases, and mortality. Of particular concern is the rapid and common spread of carbapenem resistance in healthcare settings. Carbapenems are a class of critical antibiotics reserved for treatment against multidrug-resistant microorganisms, and resistance to this antibiotic may result in limited treatment against infections. In addition to in clinical facilities, carbapenem resistance has also been identified in aquatic niches, including marine environments. Various carbapenem-resistant genes (CRGs) have been detected in different marine settings, with the majority of the genes incorporated in mobile genetic elements, i.e., transposons or plasmids, which may contribute to efficient genetic transfer. This review highlights the potential of the marine environment as a reservoir for carbapenem resistance and provides a general overview of CRG transmission among marine microbes.

A Day at the Beach: Enabling Coastal Water Quality Prediction with High-Frequency Sampling and Data-Driven Models

To reduce the incidence of recreational waterborne illness, fecal indicator bacteria (FIB) are measured to assess water quality and inform beach management. Recently, predictive FIB models have been used to aid managers in making beach posting and closure decisions. However, those predictive models must be trained using rich historical data sets consisting of FIB and environmental data that span years, and many beaches lack such data sets. Here, we investigate whether water quality data collected during discrete short duration, high-frequency beach sampling events (e.g., samples collected at sub-hourly intervals for 24-48 h) are sufficient to train predictive models that can be used for beach management. We use data collected during six high-frequency sampling events at three California marine beaches and train a total of 126 models using common data-driven techniques. Tide, solar irradiation, water temperature, significant wave height, and offshore wind speed were found to be the most important environmental variables in the models. We validate the predictive performance of models using withheld data. Random forests are consistently the top performing model type. Overall, we find that data-driven models trained using high-frequency FIB and environmental data perform well at predicting water quality and can be used to inform public health decisions at beaches.

Evaluating health risks associated with exposure to ambient surface waters during recreational activities: A systematic review and meta-analysis

Recreational water quality guidelines protect the public from health risks associated with water recreation by helping to prevent unacceptable concentrations of pathogenic organisms in ambient water. However, illness risk is associated with both the concentration of pathogens in the water and the degree of contact with those pathogens. Different recreational activities can result in different levels of contact with ambient water containing water-borne pathogens. We conducted a systematic literature review and meta-analysis to evaluate risks of illness associated with different recreational activities and different levels of contact to ambient surface waters. We screened 8,618 potentially relevant studies for quantitative measures of risk using inclusion/exclusion criteria established in advance. We categorized recreational activities as swimming, sports-related contact, minimal contact, and sand contact. We combined relative risks using a random effects meta-analysis for adverse health outcome categories representing gastrointestinal illness, respiratory illness, skin, eye, ear, nose, throat, and cold/flu illness. We identified 92 studies meeting our inclusion criteria. Pooled risk estimates indicate significant elevation of gastrointestinal illness with the recreational activity categories swimming (2.19, 95% CI: 1.82, 2.63) and sports-related contact (2.69, 95% CI: 1.04, 6.92), and nonsignificant elevation of gastrointestinal illness with minimal contact (1.27, 95% CI: 0.74, 2.16). We also found a significant elevation of respiratory illness with swimming (1.78, 95% CI: 1.38, 2.29) and sports-related contact (1.49, 95% CI: 1.00, 2.24), and no elevation of respiratory illness with minimal contact (0.90, 95% CI: 0.71, 1.14). This study suggests that exposures associated with different types of recreational activities are important characteristics of the exposure pathway when assessing illness risk associated with recreation in ambient surface waters.

Diversity and Genetic Basis for Carbapenem Resistance in a Coastal Marine Environment

Resistance to the "last-resort" antibiotics, such as carbapenems, has led to very few antibiotics being left to treat infections by multidrug-resistant bacteria. Spread of carbapenem resistance (CR) has been well characterized for the clinical environment. However, there is a lack of information about its environmental distribution. Our study reveals that CR is present in a wide range of Gram-negative bacteria in the coastal seawater environment, including four phyla, eight classes, and 30 genera. These bacteria were likely introduced into seawater via stormwater flows. Some CR isolates found here, such as Acinetobacter junii, Acinetobacter johnsonii, Brevundimonas vesicularis, Enterococcus durans, Pseudomonas monteilii, Pseudomonas fulva, and Stenotrophomonas maltophilia, are further relevant to human health. We also describe a novel metallo-β-lactamase (MBL) for marine Rheinheimera isolates with CR, which has likely been horizontally transferred to Citrobacter freundii or Enterobacter cloacae In contrast, another MBL of the New Delhi type was likely acquired by environmental Variovorax isolates from Escherichia coli, Klebsiella pneumoniae, or Acinetobacter baumannii utilizing a plasmid. Our findings add to the growing body of evidence that the aquatic environment is both a reservoir and a vector for novel CR genes.IMPORTANCE Resistance against the "last-resort" antibiotics of the carbapenem family is often based on the production of carbapenemases, and this has been frequently observed in clinical samples. However, the dissemination of carbapenem resistance (CR) in the environment has been less well explored. Our study shows that CR is commonly found in a range of bacterial taxa in the coastal aquatic environment and can involve the exchange of novel metallo-β-lactamases from typical environmental bacteria to potential human pathogens or vice versa. The outcomes of this study contribute to a better understanding of how aquatic and marine bacteria can act as reservoirs and vectors for CR outside the clinical setting.

Bacterial quality of groundwater downgradient of onsite wastewater disposal systems and the influence on eastern Long Island's embayments

Onsite wastewater disposal systems (OWDS) can introduce bacterial and chemical contaminants, via groundwater, into aquifers and adjacent waterways. We evaluated the concentration of fecal indicator bacteria (FIB) and antibiotic resistant bacteria (ARB) in the shallow groundwater of Eastern Long Island, New York, downgradient of OWDS using cultivation approaches and analysis of 16 S rRNA genes. While FIB and ARB were detected in 80% and 67% of groundwater samples, respectively, concentrations were low, suggesting that, at least at the time of sampling, groundwater was not a large-scale source of fecal bacterial contamination to adjacent embayments. ARB isolates did not include common fecal associated genera and the concentration of FIB and ARB did not correlate well with the concentration of pharmaceutical contaminants, suggesting that bacterial contaminants were poorly linked to OWDS discharge. Concentrations of FIB in the studied embayments were significantly greater in nearshore compared to mid-channel environments, suggesting that land-based sources are likely to be the major contributors of bacterial contamination.

Risk-based water quality thresholds for coliphages in surface waters: effect of temperature and contamination aging

Coliphages, viruses that infect Escherichia coli, have been used for decades to assess surface water quality yet there is no guideline for interpreting their concentrations. The present study uses a quantitative microbial risk assessment (QMRA) framework to derive risk-based surface water quality thresholds for somatic and F+ or male-specific coliphages. The risk-based threshold is the concentration at which the risk of gastro-intestinal illness is simulated to be 32/1000. The framework specifically investigates a simplified hazard scenario where recreational swimmers come into contact with water contaminated with untreated sewage containing coliphages and enteric pathogens. The framework considers exposure to sewage of diverse ages and thus accounts for the decay of coliphages and pathogens over time. As decay rate constants depend on temperature, the model considers the effect of temperature on the risk-based threshold. When exposure to fresh, unaged sewage contamination occurs, the risk-based water quality threshold for somatic and F+ coliphages is 60 PFU per 100 mL and 30 PFU per 100 mL, respectively, and temperature independent. The risk-based threshold decreases as the contamination ages because, on average, coliphages decay more quickly than norovirus, the pathogen that contributes the most to risk. The decrease in the risk-based threshold with contaminant age is equal to the difference in the first order decay rate constants of coliphages and norovirus. Since coliphage decay rate constants are larger at 25 °C than at 15 °C, and norovirus decay rate constants are a weak function of temperature, risk-based thresholds decrease more quickly with age at 25 °C than at 15 °C. For the common case where the age of contamination is unknown, the risk-based threshold for both coliphages is between ∼1 PFU per 100 mL and ∼10 PFU per 100 mL, depending on model assumptions. Future work can apply this QMRA framework for identifying risk-based thresholds for coliphages from different hazards (treated wastewater or animal feces) or from mixtures of contamination of different ages and sources.

Is it safe to go back into the water? A systematic review and meta-analysis of the risk of acquiring infections from recreational exposure to seawater

Background

Numerous illnesses are associated with bathing in natural waters, although it is assumed that the risk of illness among bathers exposed to relatively clean waters found in high-income countries is negligible. A systematic review was carried out to quantify the increased risk of experiencing a range of adverse health outcomes among bathers exposed to coastal water compared with non-bathers.

Methods

In all 6919 potentially relevant titles and abstracts were screened, and from these 40 studies were eligible for inclusion in the review. Odds ratios (OR) were extracted from 19 of these reports and combined in random-effect meta-analyses for the following adverse health outcomes: incident cases of any illness, ear infections, gastrointestinal illness and infections caused by specific microorganisms.

Results

There is an increased risk of experiencing symptoms of any illness [OR = 1.86, 95% confidence interval (CI): 1.31 to 2.64, P = 0.001] and ear ailments (OR = 2.05, 95% CI: 1.49 to 2.82, P < 0.001) in bathers compared with non-bathers. There is also an increased risk of experiencing gastrointestinal ailments (OR = 1.29, 95% CI: 1.12 to 1.49, P < 0.001).

Conclusions

This is the first systematic review to evaluate evidence on the increased risk of acquiring illnesses from bathing in seawater compared with non-bathers. Our results support the notion that infections are acquired from bathing in coastal waters, and that bathers have a greater risk of experiencing a variety of illnesses compared with non-bathers.

Implementation of an automated beach water quality nowcast system at ten California oceanic beaches

Fecal indicator bacteria like Escherichia coli and entercococci are monitored at beaches around the world to reduce incidence of recreational waterborne illness. Measurements are usually made weekly, but FIB concentrations can exhibit extreme variability, fluctuating at shorter periods. The result is that water quality has likely changed by the time data are provided to beachgoers. Here, we present an automated water quality prediction system (called the nowcast system) that is capable of providing daily predictions of water quality for numerous beaches. We created nowcast models for 10 California beaches using weather, oceanographic, and other environmental variables as input to tuned regression models to predict if FIB concentrations were above single sample water quality standards. Rainfall was used as a variable in nearly every model. The models were calibrated and validated using historical data. Subsequently, models were implemented during the 2017 swim season in collaboration with local beach managers. During the 2017 swim season, the median sensitivity of the nowcast models was 0.5 compared to 0 for the current method of using day-to-week old measurements to make beach posting decisions. Model specificity was also high (median of 0.87). During the implementation phase, nowcast models provided an average of 140 additional days per beach of updated water quality information to managers when water quality measurements were not made. The work presented herein emphasizes that a one-size-fits all approach to nowcast modeling, even when beaches are in close proximity, is infeasible. Flexibility in modeling approaches and adaptive responses to modeling and data challenges are required when implementing nowcast models for beach management.

Can We Swim Yet? Systematic Review, Meta-Analysis, and Risk Assessment of Aging Sewage in Surface Waters

This study investigated the risk of gastrointestinal illness associated with swimming in surface waters with aged sewage contamination. First, a systematic review compiled 333 first order decay rate constants ( k) for human norovirus and its surrogates feline calicivirus and murine norovirus, Salmonella, Campylobacter, Escherichia coli O157:H7, Giardia, and Cryptosporidium, and human-associated indicators in surface water. A meta-analysis investigated effects of sunlight, temperature, and water matrix on k. There was a relatively large number of k for bacterial pathogens and some human-associated indicators ( n > 40), fewer for protozoans ( n = 14-22), and few for human norovirus and its Caliciviridae surrogates ( n = 2-4). Average k ranked: Campylobacter > human-associated markers > Salmonella> E. coli O157:H7 > norovirus and its surrogates > Giardia > Cryptosporidium. Compiled k values were used in a quantitative microbial risk assessment (QMRA) to simulate gastrointestinal illness risk associated with swimming in water with aged sewage contamination. The QMRA used human-associated fecal indicator HF183 as an index for the amount of sewage present and thereby provided insight into how risk relates to HF183 concentrations in surface water. Because exposure to norovirus contributed the majority of risk, and HF183 k is greater than norovirus k, the risk associated with exposure to a fixed HF183 concentration increases with the age of contamination. Swimmer exposure to sewage after it has aged ∼3 days results in median risks less than 30/1000. A risk-based water quality threshold for HF183 in surface waters that takes into account uncertainty in contamination age is derived to be 4100 copies/100 mL.

Transcriptional Response of Staphylococcus aureus to Sunlight in Oxic and Anoxic Conditions

The transcriptional response of Staphylococcus aureus strain Newman to sunlight exposure was investigated under both oxic and anoxic conditions using RNA sequencing to gain insight into potential mechanisms of inactivation. S. aureus is a pathogenic bacterium detected at recreational beaches which can cause gastrointestinal illness and skin infections, and is of increasing public health concern. To investigate the S. aureus photostress response in oligotrophic seawater, S. aureus cultures were suspended in seawater and exposed to full spectrum simulated sunlight. Experiments were performed under oxic or anoxic conditions to gain insight into the effects of oxygen-mediated and non-oxygen-mediated inactivation mechanisms. Transcript abundance was measured after 6 h of sunlight exposure using RNA sequencing and was compared to transcript abundance in paired dark control experiments. Culturable S. aureus decayed following biphasic inactivation kinetics with initial decay rate constants of 0.1 and 0.03 m² kJ⁻¹ in oxic and anoxic conditions, respectively. RNA sequencing revealed that 71 genes had different transcript abundance in the oxic sunlit experiments compared to dark controls, and 18 genes had different transcript abundance in the anoxic sunlit experiments compared to dark controls. The majority of genes showed reduced transcript abundance in the sunlit experiments under both conditions. Three genes (ebpS, NWMN_0867, and NWMN_1608) were found to have the same transcriptional response to sunlight between both oxic and anoxic conditions. In the oxic condition, transcripts associated with porphyrin metabolism, nitrate metabolism, and membrane transport functions were increased in abundance during sunlight exposure. Results suggest that S. aureus responds differently to oxygen-dependent and oxygen-independent photostress, and that endogenous photosensitizers play an important role during oxygen-dependent indirect photoinactivation.

Antimicrobial Susceptibility of Staphylococcus aureus Isolated from Recreational Waters and Beach Sand in Eastern Cape Province of South Africa

Background: Resistance of Staphylococcus aureus to commonly used antibiotics is linked to their ability to acquire and disseminate antimicrobial-resistant determinants in nature, and the marine environment may serve as a reservoir for antibiotic-resistant bacteria. This study determined the antibiotic sensitivity profile of S.aureus isolated from selected beach water and intertidal beach sand in the Eastern Cape Province of South Africa. Methods: Two hundred and forty-nine beach sand and water samples were obtained from 10 beaches from April 2015 to April 2016. Staphylococcus aureus was isolated from the samples using standard microbiological methods and subjected to susceptibility testing to 15 antibiotics. Methicillin-resistant Staphylococcus aureus (MRSA) was detected by susceptibility to oxacillin and growth on Brilliance MRSA II agar. Antibiotic resistance genes including mecA, femA rpoB, blaZ, ermB, ermA, ermC, vanA, vanB, tetK and tetM were screened. Results: Thirty isolates (12.3%) were positive for S. aureus by PCR with over 50% showing phenotypic resistance to methicillin. Resistance of S. aureus to antibiotics varied considerably with the highest resistance recorded to ampicillin and penicillin (96.7%), rifampicin and clindamycin (80%), oxacillin (73.3%) and erythromycin (70%). S.aureus revealed varying susceptibility to imipenem (96.7%), levofloxacin (86.7%), chloramphenicol (83.3%), cefoxitin (76.7%), ciprofloxacin (66.7%), gentamycin (63.3%), tetracycline and sulfamethoxazole-trimethoprim (56.7%), and vancomycin and doxycycline (50%). All 30 (100%) S. aureus isolates showed multiple antibiotic-resistant patterns (resistant to three or more antibiotics). The mecA, femA, rpoB, blaZ, ermB and tetM genes were detected in 5 (22.7%), 16 (53.3%), 11 (45.8%), 16 (55.2%), 15 (71.4%), and 8 (72.7%) isolates respectively; Conclusions: Results from this study indicate that beach water and sand from the Eastern Cape Province of South Africa may be potential reservoirs of antibiotic-resistant S. aureus which could be transmitted to exposed humans and animals.

Staphylococcus aureus Strain Newman Photoinactivation and Cellular Response to Sunlight Exposure

Sunlight influences microbial water quality of surface waters. Previous studies have investigated photoinactivation mechanisms and cellular photostress responses of fecal indicator bacteria (FIB), including Escherichia coli and enterococci, but further work is needed to characterize photostress responses of bacterial pathogens. Here we investigate the photoinactivation of Staphylococcus aureus (strain Newman), a pigmented, waterborne pathogen of emerging concern. We measured photodecay using standard culture-based assays and cellular membrane integrity and investigated photostress response by measuring the relative number of mRNA transcripts of select oxidative stress, DNA repair, and metabolism genes. Photoinactivation experiments were performed in both oxic and anoxic systems to further investigate the role of oxygen-mediated and non-oxygen-mediated photoinactivation mechanisms. S. aureus lost culturability much faster in oxic systems than in anoxic systems, indicating an important role for oxygen in photodecay mechanisms. S. aureus cell membranes were damaged by sunlight exposure in anoxic systems but not in oxic systems, as measured by cell membrane permeability to propidium iodide. After sunlight exposure, S. aureus increased expression of a gene coding for methionine sulfoxide reductase after 12 h of sunlight exposure in the oxic system and after 6 h of sunlight exposure in the anoxic system, suggesting that methionine sulfoxide reductase is an important enzyme for defense against both oxygen-dependent and oxygen-independent photostresses. This research highlights the importance of oxygen in bacterial photoinactivation in environmentally relevant systems and the complexity of the bacterial photostress response with respect to cell structure and transcriptional regulation.IMPORTANCEStaphylococcus aureus is a pathogenic bacterium that causes gastrointestinal, respiratory, and skin infections. In severe cases, S. aureus infection can lead to life-threatening diseases, including pneumonia and sepsis. Cases of community-acquired S. aureus infection have been increasing in recent years, pointing to the importance of considering S. aureus transmission pathways outside the hospital environment. Associations have been observed between recreational water contact and staphylococcal skin infections, suggesting that recreational waters may be an important environmental transmission pathway for S. aureus However, prediction of human health risk in recreational waters is hindered by incomplete knowledge of pathogen sources, fate, and transport in this environment. This study is an in-depth investigation of the inactivation of a representative strain of S. aureus by sunlight exposure, one of the most important factors controlling the fate of microbial contaminants in clear waters, which will improve our ability to predict water quality changes and human health risk in recreational waters.

Debromoaplysiatoxin as the Causative Agent of Dermatitis in a Dog after Exposure to Freshwater in California

Contamination of recreational waters with cyanobacterial toxins continues to increase and presents a risk to animals and humans. Although cases of acute hepato- and neurotoxicoses in dogs following cyanotoxin exposure exist, no reports of skin-related reactions in dogs exist. A 5-year-old female spayed 34 kg Bracco Italiano was initially presented for rapid onset of severe pruritus and urticaria. Marked excoriation and erythema were noted over the chest and neck, while urticaria was noted in the inguinal regions and ventral abdomen. Initial basic dermatology work-up excluded parasitic, fungal, and bacterial organisms. Due to the severity and progression of urticaria, the dog received IV dexamethasone and IM diphenhydramine. Improvement of the urticaria and the dog’s clinical status was noted over the next 45 min. Assessment of the dog’s environment revealed access to a lake on the property with visible algal bloom. Water from the lake was submitted for toxicology testing and revealed the presence of debromoaplysiatoxin. Access to the lake was discontinued and follow-up evaluation over the next few weeks revealed a complete resolution of the skin irritation. To the authors’ knowledge, this is the first case report of debromoaplysiatoxin exposure in a dog after swimming in cyanobacteria-contaminated water. Veterinarians should recognize the potential harm that contaminated waters may cause in terms of dermal, hepatic, and neurological conditions. In addition, more prudent oversight of contaminated recreational waters is recommended for animals and humans to prevent adverse events and intoxications.

Fecal indicator bacteria in tropical beach sand: Baseline findings from Port Dickson coastline, Strait of Malacca (Malaysia)

This pilot study aims to assess Escherichia coli (E. coli) contamination and its perceived health risks among beachgoers in ten tropical beach sands along Port Dickson coastline (Malaysia). This study also aims to determine the relationship between perceived health symptoms and tropical beach sand exposure behavior. The concentration of E. coli in tropical beach sand ranged from 60cfu/100g to 4113cfu/100g. E. coli contamination was the highest at Tanjung Gemuk (4113±30cfu/100g) and the lowest at Tanjung Tuan (60±15cfu/100g); the high level of contamination could be due to the location of the former at the sewage outlet of nearby hotels. Skin symptoms were the most predominant among the health symptoms indicated by beachgoers. Exposure duration was significantly correlated with the perceived health symptoms among beachgoers in the beaches studied.

A multi-beach study of Staphylococcus aureus, MRSA, and enterococci in seawater and beach sand

Incidences of Staphylococcus aureus and methicillin resistant S. aureus (MRSA) have risen worldwide prompting a need to better understand routes of human exposure and whether standard bacterial water quality monitoring practices adequately account for this potential threat. Beach water and sand samples were analyzed during summer months for S. aureus, enterococci, and MRSA at three southern California beaches (Avalon, Doheny, Malibu Surfrider). S. aureus frequently was detected in samples of seawater (59%, n = 328) and beach sand (53%, n = 358). MRSA sometimes was detected in seawater (1.6%, n = 366) and sand (2.7%, n = 366) at relatively low concentrations. Site specific differences were observed, with Avalon Beach presenting the highest concentrations of S. aureus and Malibu Surfrider the lowest in both seawater and sand. S. aureus concentrations in seawater and sand were correlated to each other and to a variety of other parameters. Multiple linear regression on the combined beach data indicated that significant explanatory variables for S. aureus in seawater were S. aureus in sand, water temperature, enterococci in seawater, and the number of swimmers. In sand, S. aureus concentrations were related to S. aureus in seawater, water temperature, enterococci in seawater, and inversely to surf height classification. Only the correlation to water temperature held for individually analyzed beaches and for S. aureus concentrations in both seawater and sand. To provide context for these results, the prevalence of S. aureus in sand was compared to published fomite studies, and results suggested that beach prevalence was similar to that in homes.

Elevated bathing-associated disease risks despite certified water quality: a cohort study

Bacteriological water quality criteria have been recommended to ensure bathers' health. However, this risk-assessment approach is based mainly on routine measurements of fecal pollution indicator bacteria in seawater, and may not be adequate to protect bathers effectively. The aim of this study was to assess the risks of symptoms related to infectious diseases among bathers after exposure to seawater which was of excellent quality according to EU guidelines. This study is a cohort study recruiting bathers and non-bathers. Water samples were collected for estimating bacterial indicators. Univariable and multivariable analysis was performed to compare the risks of developing symptoms/diseases between bathers and non-bathers. A total of 3805 bathers and 572 non-bathers were included in the study. Water analysis results demonstrated excellent quality of bathing water. Significantly increased risks of symptoms related to gastrointestinal infections (OR = 3.60, 95% CI 1.28-10.13), respiratory infections (OR = 1.92, 95% CI 1.00-3.67), eye infections (OR = 2.43, 95% CI 1.27-4.63) and ear infections (OR = 17.21, 95% CI 2.42-122.34) were observed among bathers compared with non-bathers. Increased rates of medical consultation and medication use were also observed among bathers. There was evidence that bathers experienced increased morbidity compared with non-bathers though the bathing waters met bacteriological water quality criteria. These results suggest that risk assessments of recreational seawaters should not only focus on bacteriological water quality criteria.

Evaluation of sewage source and fate on southeast Florida coastal reefs

Water, sponge and coral samples were collected from stations impacted by a variety of pollution sources and screened for human enteric viruses as conservative markers for human sewage. While human enteroviruses and adenoviruses were not detected, noroviruses (NoV; human genogroups I and II) were detected in 31% of samples (especially in sponge tissue). Stations near inlets were the only ones to show multiple sample types positive for NoV. Fecal indicator bacteria and enteric viruses were further evaluated at multiple inlet stations on an outgoing tide. Greatest indicator concentrations and highest prevalence of viruses were found at the mouth of the inlet and offshore in the inlet plume. Results suggest that inlets moving large volumes of water into the coastal zone with tides may be an important source of fecal contaminants. Efforts to reduce run-off or unintended release of water into the Intracoastal Waterway may lower contaminants entering sensitive coastal areas.

Integral assessment of pollution in the Suquía River (Córdoba, Argentina) as a contribution to lotic ecosystem restoration programs

The Suquía River lower-middle basin (Córdoba, Argentina) is subject to a strong anthropic impact because it receives pollutants from different sources (industries, wastewaters, heavy traffic, agricultural land use, etc.) We have assessed the degree of watershed degradation of Suquía River lower-middle sections through the analysis of different ecosystem compartments (air, water, riparian soil, sediments and biota), in order to provide useful data to be considered in future river restoration programs. Four study sites were selected along the river (La Calera city, Córdoba city, Corazón de María village and Río Primero city) which were sampled during the low- and high-water flow periods. We analyzed: a) chemical and physical characteristics of water, sediments, and riparian soil; b) heavy metal content of water and sediments, and c) semi-volatile organic compounds in air. Besides, pollutant bioindicators such as fish assemblages, lichens (Usnea amblyoclada), vascular plants (Tradescantia pallida), and microorganisms (fecal coliform and Escherichia coli) were used to further assess the status of the river. All analyzed ecological compartments were affected by water pollution, particularly, fish assemblages, sediments and riparian soils by heavy metal and coliform bacteria. Moreover, we detected a possible contribution of sulfur and a high pollutant content in air that merit further research about other air-water exchanges. Accordingly, we strongly suggest that an action to restore or remediate the anthropic effect on the Suquía River be extended to all possible compartments along the river.

Bacterial pathogens in Hawaiian coastal streams--associations with fecal indicators, land cover, and water quality

This work aimed to understand the distribution of five bacterial pathogens in O'ahu coastal streams and relate their presence to microbial indicator concentrations, land cover of the surrounding watersheds, and physical-chemical measures of stream water quality. Twenty-two streams were sampled four times (in December and March, before sunrise and at high noon) to capture seasonal and time of day variation. Salmonella, Campylobacter, Staphylococcus aureus, Vibrio vulnificus, and V. parahaemolyticus were widespread -12 of 22 O'ahu streams had all five pathogens. All stream waters also had detectable concentrations of four fecal indicators and total vibrio with log mean ± standard deviation densities of 2.2 ± 0.8 enterococci, 2.7 ± 0.7 Escherichia coli, 1.1 ± 0.7 Clostridium perfringens, 1.2 ± 0.8 F(+) coliphages, and 3.6 ± 0.7 total vibrio per 100 ml. Bivariate associations between pathogens and indicators showed enterococci positively associated with the greatest number of bacterial pathogens. Higher concentrations of enterococci and higher incidence of Campylobacter were found in stream waters collected before sunrise, suggesting these organisms are sensitive to sunlight. Multivariate regression models of microbes as a function of land cover and physical-chemical water quality showed positive associations between Salmonella and agricultural and forested land covers, and between S. aureus and urban and agricultural land covers; these results suggested that sources specific to those land covers may contribute these pathogens to streams. Further, significant associations between some microbial targets and physical-chemical stream water quality (i.e., temperature, nutrients, turbidity) suggested that organism persistence may be affected by stream characteristics. Results implicate streams as a source of pathogens to coastal waters. Future work is recommended to determine infectious risks of recreational waterborne illness related to O'ahu stream exposures and to mitigate these risks through control of land-based runoff sources.

Bilateral mastoiditis from red tide exposure

BACKGROUND

Bilateral mastoiditis in adults has previously been reported only in association with diabetes mellitus or immunocompromised patients.

OBJECTIVES

To describe a case of bilateral mastoiditis in a healthy adult and to investigate the etiology.

CASE REPORT

A 53-year-old woman presented to the Emergency Department with bilateral otitis externa and mastoiditis after scuba diving during a harmful algal bloom, commonly known as a "red tide." The levels of coliform bacteria recorded at the time and location of her dive exceeded health regulatory limits and correlate with her atypical culture results.

CONCLUSION

Elevated bacterial counts that result from harmful algal blooms may account for this rare infection.