Water Recreational Activities Research Articles

Impact of Hydrogen Peroxide and Copper Sulfate on the Delayed Release of Microcystin

Algicides, like hydrogen peroxide and copper sulfate, are commonly applied to recreational waters and drinking water sources to mitigate cyanobacterial blooms. In this work, the effects of hydrogen peroxide and copper sulfate were evaluated in two natural bloom samples (collected from Canadian and American waterbodies) and one lab-cultured Microcystis aeruginosa suspended in Colorado River water. Five algicide to dissolved organic carbon (DOC) dose ratios were evaluated during an initial exposure period of 24 h. One dose ratio (0.4 H2O2:DOC or 0.25 CuSO4:DOC) was then evaluated during stagnation after quenching (hydrogen peroxide) or extended exposure (copper sulfate) for up to 96 or 168 h. During the initial hydrogen peroxide exposure, the CA bloom had no release of intracellular microcystins (MCs) and the USA bloom only released MC at 4 H2O2:DOC. The reverse occurred with copper sulfate, where the CA bloom released MCs at 0.6 CuSO4:DOC but the USA bloom had no detectable extracellular MCs. Extracellular MC was released from the lab-cultured Microcystis at the lowest hydrogen peroxide and copper sulfate doses. In the hydrogen peroxide stagnation experiment, intracellular MC decreased in the USA bloom after 168 h despite the low dose applied. Similarly, the extended copper sulfate exposure led to intracellular MC decreases in both bloom samples after 168 h, despite showing no impact during the initial 24 h monitoring period. The lab-cultured Microcystis was again less resistant to both algicides, with releases observed after less than 2 h of stagnation or exposure. The damage to cells as measured by pigments during these experiments did not match the MC data, indicating that blooms with depressed pigment levels can still be a risk to nearby drinking water sources or recreational activities. These results provide insight on the timeline (up to one week) required for monitoring the potential release of MCs after algicide application.

Leptospirosis trends in China, 2007-2018: A retrospective observational study.

Leptospirosis is one of the most common and neglected tropical waterborne diseases in China, causing serious economic losses, and constituting a significant public health threat. Leptospirosis has recently received increased attention and is considered a re-emerging infectious disease in many countries. The incidence of leptospirosis among people suggests that occupation, age, season, sex and water recreational activities are significant risk factors. The aim of this study was to describe the epidemiological profiles of leptospirosis in China during the 2007-2018 period. The morbidity data of leptospirosis by age, season (month), gender, occupation and geographic location (different provinces) were obtained from the public health science data centre of China for subsequent epidemiological analysis. The results indicate that the incidence of leptospirosis has shown a slow downward trend from 2007 to 2018, but morbidity rates were still relatively high (0.0660-0.0113). The incidence of leptospirosis varied in different provinces of China; cases localized mainly to the Southern and Central provinces, areas with warm weather and ample rainfall. Older people (aged 60-75), males, farmers, students and field workers were high-risk populations. During the 2007-2018 observation period, morbidity rates increased beginning in May, remained at high levels in August and September and decreased after November. The present investigation highlights the re-emergence of leptospirosis in some provinces of China (especially in Yunnan and Fujian) and shows that leptospirosis remains a serious public health threat. The results of this study should enhance measures taken for the prevention, control, and surveillance of leptospirosis in China.

1626. A Primary Amebic Meningoencephalitis Case Associated with Surfing in an Inland Surf Park

Background Naegleria fowleri is a thermophilic ameba that is found in freshwater and causes primary amebic meningoencephalitis (PAM; 0–8 infections per year in the United States) when it enters the nose and migrates to the brain. Patient exposure to water containing the ameba typically occurs in warm freshwater lakes and ponds during recreational water activities. In September 2018, a 29-year-old man died of PAM after visiting a Texas inland surf park.MethodsTo determine water exposures, we reviewed medical records and conducted interviews with family and individuals who had traveled with the patient. To further investigate the inland surf park as a possible exposure source, we visited the facility and collected water, biofilm, and sediment samples from the surf park and other venues (water slides, lazy river, and cable park) within the facility. We assessed water sources and treatment practices, performed water quality tests, and tested for the presence of N. fowleri by culture and real-time PCR.ResultsInterviews revealed that the case-patient’s most probable water exposure in the 10 days before becoming ill occurred while surfing in an inland freshwater surf park where he fell off the surfboard into the water multiple times. The on-site investigation of the facility revealed a practice of manual chlorine treatment with monitoring, but no water filtering or record keeping to document water quality. Surf park water temperature was warm (25°C) and chlorine residual was negligible. N. fowleri was detected in 1 water and 1 sediment sample collected at the cable park venue, and viable thermophilic amebae were detected in all samples collected from the surf park, water slide, and cable park venues, as well from the sediment in the open-air groundwater reservoir feeding the venues.ConclusionThis investigation documents a novel exposure in an inland surf park as the likely exposure causing PAM. Conditions in the surf park were conducive to amebic growth. Novel types of recreational water venues that do not meet traditional definitions of swimming pools, such as this surf park, might not meet the water quality standards for pools or similar treated venues. Clinicians and public health officials should remain vigilant for nontraditional exposures to water.Disclosures All authors: No reported disclosures.

Surveillance of Enteric Viruses and Thermotolerant Coliforms in Surface Water and Bivalves from a Mangrove Estuary in Southeastern Brazil.

This study was conducted to evaluate the microbiological quality of a mangrove estuary in the Vitória Bay region, Espírito Santo, Brazil. We analyzed the presence and concentration of enteric viruses and thermotolerant coliforms in water, mussels (Mytella charruana and Mytella guyanensis), and oysters (Crassostrea rhizophorae), collected over a 13-month period. Human adenovirus, rotavirus A (RVA), and norovirus genogroup II were analyzed by quantitative PCR. The highest viral load was found in RVA-positive samples with a concentration of 3.0 × 104genome copies (GC)L-1 in water samples and 1.3 × 105GCg-1 in bivalves. RVA was the most prevalent virus in all matrices. Thermotolerant coliforms were quantified as colony-forming units (CFU) by the membrane filtration method. The concentration of these bacteria in water was in accordance with the Brazilian standard for recreational waters (< 250CFU 100mL-1) during most of the monitoring period (12 out of 13months). However, thermotolerant coliform concentrations of 3.0, 3.1, and 2.6 log CFU 100g-1 were detected in M. charruana, M. guyanensis, and C. rhizophorae, respectively. The presence of human-specific viruses in water and bivalves reflects the strong anthropogenic impact on the mangrove and serves as an early warning of waterborne and foodborne disease outbreaks resulting from the consumption of shellfish and the practice of water recreational activities in the region.

Variation of efficiencies and limits of ultrasonication for practical algal bloom control in fields

Algal blooms are an increasing issue in managing water resources for drinking water production and recreational activities in many countries. Among various techniques, ultrasonication is known as a cost-effective method for control of harmful algal blooms (HABs) in relatively large area of water bodies. Most of engineering parameters for operating ultrasonication have been empirically determined based on laboratory scale tests, however, field or pilot tests in real environments are still rare. For field application, duration of ultrasonication is often on a monthly basis which is impractical for stream where there is flow and thus retention time is short. More realistic experimental approaches are required for practical applications of ultrasound. In this study, relatively low frequencies (36–175 kHz) of ultrasonication with low power intensity, less than 650 W, were tested for algal control in various pilot (100–750 L) and field (4 m3) tests in a short duration (<20 min). Generally, rapid decline of sound pressure (Pa) of ultrasonication was observed with distance (80% decrease even with 0.5 m difference). In a pilot test (100 L), the highest algae reduction was achieved at 36 kHz with 0.003 W mL−1 of power density within 10 min duration, but there was a noticeable increase in microcystin due to damaged algal cells by the low frequency of ultrasound. In a short-term operation without flow, distance from the ultrasound system was an important parameter for effective algae reduction, while longer exposure time ensured sufficient algae reduction. In a circulation pond (4 m3) with flow, 108 kHz–450 W showed the greatest efficiency in algal control and approximately 50–90% algal cells reduction was observed at 36–175 kHz with less than 650 W power and 60 min duration.

Outbreak of swimmer's itch in Central Italy: Description, causative agent and preventive measures.

Swimmer's itch is caused by the penetration of free-swimming larvae of trematodes of the family Schistosomatidae in human skin. It is usually reported in people engaged in recreational water activities in freshwater bodies and in most of cases, it is provoked by bird schistosomes of the genus Trichobilharzia. In the summer 2017, many cases of dermatitis were recorded in people bathing in the waters of the Albano Lake (Rome, Italy) and a parasitological investigation was carried out in order to ascertain the causative agent of these cases. Snails of the family Lymnaeidae, natural intermediate hosts of bird schistosomes, were collected from lake shallow waters to detect the presence of trematodes of the genus Trichobilharzia. Pools of maximum 10 snails were placed in Petri dishes, and cercarial emergence was stimulated exposing snails to strong artificial light intensity at 25°C. Three hundred and thirty-seven snails were collected and screened for the shedding of cercariae. Furcocercariae of the family Schistosomatidae, with a morphology overlapping that of the genus Trichobilharzia, were detected in seven Petri dishes. Assuming that in each positive Petri dish just one snail was shedding furcocercariae, the minimum infectious rate was 2.1%. Molecular analysis of furcocercariae allowed ascribing them to the species Trichobilharzia franki. Snails of the species Radix auricularia were identified as intermediate hosts of the parasite. This is the second record of T. franki causing cercarial dermatitis in Central Italy, the third in Italy. The 2017 was in Italy exceptionally warm and dry. Trematodes are sensitive to changes in temperature, being cercarial production and emission rates temperature dependent. Small increases in water temperature would speed up parasite development and transmission, leading to a manifold increase in cercarial emergence. Moreover, high temperatures raise chances to acquire the infection, due to increased time spent in water by people.

Influence of physico-chemical characteristics of sediment on the in situ spatial distribution of F-specific RNA phages in the riverbed.

ABSTRACTRiverbed sediment is commonly described as an enteric virus reservoir and thought to play an important role in water column contamination, especially during rainfall events. Although the occurrence and fate of faecal-derived viruses are fairly well characterized in water, little information is available on their presence as their interactions with sediment. This study aimed at determining the main environmental factors responsible for the presence of enteric viruses in riverbed sediment. Using a combination of microbiological and physico-chemical analyses of freshly field-sampled sediments, we demonstrated their contamination by faecal phages. The in situ spatial distribution of phages in sediment was mainly driven by sediment composition. A preferential phage accumulation occurred along one bank of the river, where the quantity of fine sands and clay particles smaller than 0.2 mm was the highest. Additionally, a mineralogical analysis revealed the influence of the heterogeneous presence of virus sorbents such as quartz, calcite, carbonates and iron-bearing phases (goethite) on the phage spatial pattern. A more precise knowledge of the composition of riverbed sediment is therefore useful for predicting preferential areas of enteric virus accumulation and should allow more accurate microbial risk assessment when using surface water for drinking water production or recreational activities.

Health risks associated with recreational water activities

Recreational water activities are becoming increasingly popular among travelers, especially for adventurous people who like to try something new in their life. The aquatic environment can provide enjoyment as well as health hazards to someone who involve in it. In particular, adventure travel and water sports are considered high-risk activities. Most of water activities are tightly regulated to ensure safety, but accidents and other risk do occur. Health risks during activities in fresh water or ocean water vary from infectious disease and drowning to marine envenomation, decompression sickness, and hypothermia. Most of the risks are highly preventable with proper planning and preparation. Travel medicine physicians need to understand the scope of the problem and provide individualized travel advice during a pre-travel consultation visit.

A survey on microbial quality and antibiotic resistance in Karoon River, Khuzestan, Iran

Karoon River is the most important river in Iran that supplies the drinking and industrial water to many cities and villages in Khuzestan. As a consequence of hospital and municipal wastewater discharge into this river, antibiotic resistance will be increased in microbial inhabitants of this ecosystem. Furthermore, microbial load is also undergone continual variation. The aim of this study was to evaluate seasonal microbial quality and antibiotic resistance in bacterial isolates. For this purpose, five stations were selected and samples were harvested during four seasons. Bacterial count was performed through culturing on Mueller–Hinton agar, and bacterial isolates were identified. Antibiotic resistance profiles of isolates as well as resistance to Hg were investigated. As a result, it was found that the least quality was in summer season while the best quality was in winter that is related to the reduction of water volume and recreational activities in summer and increasing rain and dilution of contaminants in winter season. All isolates were sensitive to Hg while antibiotic resistance and multidrug resistance were found in bacterial isolates. Based on the obtained results, it can be concluded that the microbial quality of Karoon River has variations depending on the season and it is necessary that be monitored in order to control and prevent epidemic bacterial infections and antibiotic resistance distribution.

Illnesses Associated with Freshwater Recreation During International Travel.

International travel, adventure travel, and eco-tourism are increasing over the past few decades. This review aims to summarize the spectrum of infections associated with recreational freshwater activities and international travel. Recreational water activities can be associated with a wide range of infections. Acute febrile illnesses due to leptospirosis and schistosomiasis are not uncommon in travelers following extensive freshwater exposure. Aeromonas and other water-associated pathogens are important to consider in a traveler presenting with a skin and soft tissue infection. Recreational water activities are often associated with diarrheal illnesses, especially in children, and the range of enteric pathogens includes bacterial pathogens such as Escherichia coli O157:H7 and Shigella species and the protozoan parasites Cryptosporidium and Giardia duodenalis. Infections due to free-living amebas though rare can lead to fulminant central nervous system infections. A diverse range of infections may be associated with freshwater exposure, and it is important that these entities are considered in a returning traveler presenting with an acute illness.

An Analysis of Heavy Metals in Lakes of Former Tin Mining Sites in the City of Ipoh, Perak, Malaysia

The purpose of this study was to evaluate the water quality, particularly the heavy metal parameters, at five former tin mining sites that have been used as recreational lakes: Lake Lahat, Lake Kg. Temiang, Lake Kg. Tengku Hussein, Lake Gunung Lang and Lake Taman Indah. The heavy metal parameters tested were arsenic (As), lead (Pb), copper (Cu) and zinc (Zn). The method of testing used laboratory analyses and water sample observations for 12 months between September 2015 and August 2016. Heavy metal parameters were compared with the standards published by the Department of Environment (DOE) and the Ministry of Health (MOH) to determine the quality of the lakes water. The results of the analyses showed that all of the lakes contained high concentrations of Pb compared to other metals. The amount of Pb detected in the lakes from highest to lowest concentration was Lake Kg. Tengku Hussein (1.08 mg/l), Lake Kg. Temiang (0.99 mg/l), Lake Lahat (0.96 mg/l), Lake Taman Indah (0.78 mg/l) and Lake Gunung Lang (0.60 mg/l). The metal readings of As, Cu and Zn metals were below the standards set by the DOE and MOH. Periodic research and monitoring of water quality by the Ipoh City Council (MBI) should be given attention so that the quality of the lake water, especially in relation to heavy metal elements, is under control which makes recreational water activities involving water contact are safe for the visitors’

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.

A Primary Amebic Meningoencephalitis Case Associated with Rafting on an Artificial Whitewater River

Background Naegleria fowleri is a climate-sensitive thermophilic ameba found in freshwater that causes primary amebic meningoencephalitis (PAM; 0–8 infections per year in the U.S.) when it enters the nose and migrates to the brain. Patient exposure to water containing the ameba typically occurs in warm freshwater lakes and ponds during recreational water activities. In June 2016, an 18-year-old woman died of PAM after traveling to North Carolina, where she participated in whitewater rafting on an artificial whitewater river.MethodsTo determine water exposures, we reviewed medical records and conducted interviews with family and individuals who had traveled with the case-patient. To further investigate the artificial whitewater river as a possible exposure source, we visited the whitewater facility and collected water, biofilm, and sediment samples from the facility and from the nearby natural river. We performed select water quality tests onsite and tested for the presence of N. fowleri by culture and real-time PCR in the laboratory.ResultsInterviews revealed that the case-patient’s most probable water exposure in the 10 days before becoming ill occurred while rafting on an artificial whitewater river during which she was thrown out of the raft and submerged underwater. The ~11.5 million gallons of water in the whitewater facility were filtered, subjected to UV light, and occasionally chlorinated. Heavy algal growth was noted. The free chlorine residual was 0.05 mg/L, turbidity was 6.7 NTU, and water temperature was 30°C in the whitewater facility during the site visit. All 11 water-related samples taken from the facility were positive for N. fowleri. Of 5 samples taken from the natural river, 1 sediment sample was positive for N. fowleri.ConclusionThis investigation documents a novel exposure to an artificial whitewater river as the likely exposure causing PAM in this case. Conditions in the whitewater facility (warm, turbid water with little chlorine and heavy algal growth) rendered the water treatment ineffective and provided an ideal environment for N. fowleri to thrive. The combination of natural and engineered elements at the whitewater facility create a challenging environment to control the growth of N. fowleri.Disclosures All authors: No reported disclosures.

Detection of Cryptosporidium and Cyclospora Oocysts from Environmental Water for Drinking and Recreational Activities in Sarawak, Malaysia.

Cryptosporidiosis and cyclosporiasis are caused by waterborne coccidian protozoan parasites of the genera Cryptosporidium and Cyclospora, respectively. This study was conducted to detect Cryptosporidium and Cyclospora oocysts from environmental water abstracted by drinking water treatment plants and recreational activities in Sarawak, Malaysia. Water samples (12 each) were collected from Sungai Sarawak Kanan in Bau and Sungai Sarawak Kiri in Batu Kitang, respectively. In addition, 6 water samples each were collected from Ranchan Recreational Park and UNIMAS Lake at Universiti Malaysia Sarawak, Kota Samarahan, respectively. Water physicochemical parameters were also recorded. All samples were concentrated by the iron sulfate flocculation method followed by the sucrose floatation technique. Cryptosporidium and Cyclospora were detected by modified Ziehl-Neelsen technique. Correlation of the parasites distribution with water physicochemical parameters was analysed using bivariate Pearson correlation. Based on the 24 total samples of environmental water abstracted by drinking water treatment plants, all the samples (24/24; 100%) were positive with Cryptosporidium, and only 2 samples (2/24; 8.33%) were positive with Cyclospora. Based on the 12 total samples of water for recreational activities, 4 samples (4/12; 33%) were positive with Cryptosporidium, while 2 samples (2/12; 17%) were positive with Cyclospora. Cryptosporidium oocysts were negatively correlated with dissolved oxygen (DO).

Community Structures of Phytoplankton with Emphasis on Toxic Cyanobacteria in an Ohio Inland Lake during Bloom Season.

The community structures of phytoplankton are important factors and indicators of lake water quality. Harmful algal blooms severely impact water supply, recreational activities and wildlife habitat. This study aimed to examine the phytoplankton composition and variations using microscopy, and identify harmful Cyanobacteria in weekly samples taken from four sites at Harsha Lake in southwest Ohio. Over the course of the summer in 2015, the phytoplankton of Harsha Lake consisted mainly of 13 taxa belonging to Bacillariophyta, Chlorophyta, Cryptophyta, Cyanobacteria, Dinophyta and Euglenophyta. Their significant successions started with Bacillariophyta and/or Chlorophyta, then bloomed with Cyanobacteria and ended with Chlorophyta and/or Dinophyta. Cyanobacteria members: Microcystis, Planktothrix, Dolichospermum, Aphanizomenon, Cylindrospermopsis, and Oscillatoria from the Cyanophyceae were identified to be dominant genera. These organisms varied spatially and temporally in similar patterns along with the variations of nutrients and formed the summer bloom with the total biomasses ranging from 0.01 to 114.89 mg L−1 with mean of 22.88 mg L−1. M. aeruginosa and P. rubescens were revealed as the microcystin producers, while A. circinalis and Aphanizomenon sp. were identified as a saxitoxin producer through cloning and sequencing PCR products of mcyA, mcyE and sxtA genes. The biomasses of phytoplankton, Cyanobacteria and Microcystis were positively correlated to nutrients, especially to total nitrogen. The total ELISA measurement for microcystin positively correlated with Cyanobacteria (R2 = 0.66, P < 0.0001), Microcystis (R2 = 0.64, P < 0.0001) and phytoplankton (R2 = 0.59, P < 0.0001). The basic information on the occurrence and biomasses of Cyanobacteria and total phytoplankton, and the analysis for toxic species, which were the first report for the inland water in Ohio, USA, will document the succession patterns of phytoplankton and toxin production over a season and provide data to predict risk occurrence to both human and ecological factors.

Leptospirosis: An Infectious Emerging Waterborne Zoonosis of Global Significance

Leptospirosis, caused by Leptospira interrogans, is a highly infectious emerging water borne zoonosis of global significance. It is an enigmatic life threatening disease, which results into high morbidity and mortality, particularly in poor resource nations. Disease is endemic in many countries of the world including India. Currently, over one million people are affected with leptospirosis worldwide annually. Leptospirosis presents an occupational hazard of the persons who have direct or indirect contact with the urine of infected animals. The common mode of transmission of the disease is exposure to and ingestion of urine contaminated water. Clinical signs in humans may vary from asymptomatic to severe stage with a range of non-specific symptoms. Rodents are the chief reservoir of Leptospira, and organisms are excreted in urine, thus contaminating the environment including water. Disease is endemic in tropical regions of the world with maximum cases in young male adults during the rainy season. Pollution of city water supply may result in outbreak of disease. Severe epidemics of leptospirosis are related to water recreational activities. The diagnosis of disease is confirmed by detection of serum antibodies against Leptospira and also by isolation of the pathogen from clinical specimens such as blood, cerebrospinal fluid and urine. Early treatment with antibacterial antibiotics may shorten the duration of fever and reduce the severity of the disease. As leptospirosis is attributed to physical contact with contaminated water supplies, environmental detection is important in the development of adequate control measures. There is a need to develop an effective surveillance system to monitor the trends of disease. Sincere attempts should be made to estimate the annual burden of cases and deaths due to leptospirosis. Additional studies on the epidemiology, diagnosis, chemotherapy and vaccines are required to control this life threatening zoonosis.

Spatial Variation Assessment of River Water Quality Using Environmetric Techniques

The Malacca River provides water resources, recreational activities, and habitat for aquatic animals, as well as serving as a tourist attraction. Nevertheless, the Malacca has experienced water quality changes as a result of urbanization and population growth. Environmetric techniques incorporating hierarchical cluster analysis (HCA), discriminant analysis (DA), and principal component analysis (PCA) have been applied to understand the spatial variation of water quality in nine sampling locations within the river basin. HCA has grouped the nine sampling locations into two clusters based on physico-chemical and biological water quality data and trace elements in water. DA analysis indicated that temperature, salinity, coliform, EC, DO, BOD, COD, As, Hg, Cd, Cr, and Zn are the most significant parameters that reflect the overall river water quality for discrimination in clusters 1 and 2. PCA resulted in six components in cluster 1 and eight components in cluster 2. Agricultural activities and residential areas are the main sources of pollution within cluster 1, while a sewage treatment plant and industrial activities are the main sources of pollution in cluster 2. This study has provided useful information for identifying and investigating the pollutant sources through the water quality variations in the river. However, continuous evaluation of river water quality will help in greater understanding of river water quality for a more holistic management of the river basin.

Primary Amebic Meningoencephalitis: What Have We Learned in the Last 5Years?

Primary amebic meningoencephalitis (PAM) is a devastating infection of the brain caused by the thermophilic free-living ameba, Naegleria fowleri. Infection can occur when water containing the ameba enters the body through the nose, usually during recreational water activities such as swimming or diving. Historically, in the USA, cases were mostly reported from the warmer southern-tier states. In the last 5years, several notable changes have been documented in PAM epidemiology including a northward expansion of infections and new types of water exposures. The recent reports of two PAM survivors provide hope for improved outcomes with early diagnosis and aggressive treatment. Advanced molecular laboratory tools such as genome sequencing might provide more insight into the pathogenicity of N. fowleri. Clinicians treating patients with meningitis and warm freshwater exposure are encouraged to consider PAM in their differential diagnoses.

A Rare Case of Douche Injury Sustained during Water Recreation Activities: More Protection will Mean less Injury

Douche injury is a rare consequence of water recreation activities; it can manifest as vaginal laceration or even haemoperitoneum. Such severe trauma can cause massive bleeding and hypovolaemic shock; therefore, it is potentially life threatening. Herein, we present the case of a patient who had vaginal laceration and haemoperitoneum due to water recreation activities; surgery was performed to stop the bleeding. We suggest wearing a rubber or neoprene wetsuit during water recreation activities to prevent such potentially lethal injury.

Underwater Acoustic Signatures of Recreational Swimmers, Divers, Surfers and Kayakers

Non-motorised, recreational water activities were recorded underwater in the controlled setting of a public swimming pool during the off-season. Individuals, one at a time, swam freestyle and breaststroke, snorkelled, scuba-dived, kicked a boogie board and a surfboard, kayaked, and simply jumped into the water. Underwater video and still images were recorded at the same time to interpret the sounds recorded. Most of the sound was due to bubbles generated underwater. Activities involving fins (flippers) were the loudest (boogie boarding and snorkelling), followed by freestyle swimming, surfboard paddling, and kayaking. Breaststroke generated the fewest bubbles and was the quietest. All activities produced bubbles, hence noise, at a characteristic temporal pattern. Scuba-diving exhibited two distinct noise spectra related to inhalation and exhalation. Received levels ranged from 110 to 131 dB re 1 $$\upmu $$ Pa (10–16,000 Hz) for all of the activities at the closest point of approach (1 m). The results might have applicability to the monitoring of pools for security reasons, to performance assessments of swimmers, and to studies of the distances at which humans may be detectible by marine animals in the sea.