Interference-resistant gold nanoparticle assay for detecting Enterococcus in fresh and marine waters.

Enterococci are common indicators of fecal contamination and are used to assess the quality of fresh and marine water, sand, soil, and sediment. However, samples collected from these environments contain various cells and other factors that can interfere with the assays used to detect enterococci. We developed a novel assay for the sensitive and specific detection of enterococci that is resistant to interference from other cells and environmental factors. Our interference-resistant assay used 30-nm gold nanoparticles (AuNPs), streptavidin, and a biotinylated Enterococcus antibody. Enterococci inhibited the interaction between streptavidin and biotin and led to the disaggregation of AuNPs. The absence of enterococci led to the aggregation of AuNPs, and this difference was easily detected by spectrophotometry. This interference-resistant AuNP assay was able to detect whole cells of Enterococcus in the range of 10 to 107 CFU/mL within 3 h, had high specificity for enterococci, and was unaffected by the presence of other intestinal bacteria, such as Escherichia coli. Our examination of fresh and marine water samples demonstrated no interference from other cells or environmental factors. The interference-resistant AuNP assay described here has the potential to be used as a rapid, simple, and effective method for monitoring enterococci in diverse environmental samples.

Clostridium and Cryptosporidium outbreak linked to a splash pad.

BACKGROUND: . Splash pads for recreational purposes are widespread. Using these pads can pose a health risk if they lack installation regulation and water quality supervision. Our aim was to describe a waterborne disease outbreak caused by Clostridium perfringens and Cryptosporidium spp. in a Barcelona district and the measures taken for its control. METHODS: . On August 2018, 71 cases of acute gastroenteritis were detected, affecting people who used a splash pad or were in contact with a user. Microbiological and environmental investigations were carried out. A descriptive analysis of the sample and Poisson regression models adjusted for age and sex were performed, obtaining frequencies, median values, and adjusted prevalence ratios with their 95% confidence intervals. RESULTS: The median age of the cases was 6.7 years, 27 (38%) required medical care, and three (4.2%) were hospitalized. The greater the number of times a person entered the area, the greater the number of symptoms and their severity. Nineteen (76%) of the 25 stool samples collected from cases showed the presence of one or both pathogens. Environmental investigations showed deficiencies in the facilities and identified the presence of both species in the splash pad. Health education and hygiene measures were carried out, and 14 days after the closure of the facilities, no more cases related to the pad were recorded. CONCLUSIONS: . Specific regulations are needed on the use of splash pads for recreational purposes. Until these regulations are in place, these types of facility should comply with the regulations that apply to swimming pools and spas, including those related to the design of the tanks, water recirculation systems, and adequate disinfection systems.

The role of air temperature in Legionella water contamination and legionellosis incidence rates in southern Italy (2018-2023).

Background: Legionnaires' disease is caused by inhalation or aspiration of small water droplets contaminated with Legionella, commonly found in natural and man-made water systems and in moist soil. Over the past 5 years, notification rates of this disease have almost doubled in the European Union (EU) / European Environmental Agency (EEA), from 1.4 in 2015 to 2.2 cases per 100,000 population in 2019. Some studies show that the greater presence of the microorganism in the water network and the increase in cases of legionellosis could be related to the variations in some environmental factors, such as air temperature, which may influence the water temperature. Study design: Climate change is currently a prominent topic worldwide because of its significant impact on the natural environment. It is responsible for the increase in numerous waterborne pathologies. The purpose of this study was to correlate the air temperature recorded in Apulia region from January 2018 to April 2023 with the presence of Legionella in the water networks of public and private facilities and the incidence rates of legionellosis during the same period. Methods: During the period from January 2018 to April 2023, water samples were collected from facilities involved in legionellosis cases and analyzed for Legionella. During the same period, all the cases notified to the regional epidemiological observatory (OER-Apulia) were included in this study. Statistical analyses were conducted using the Shapiro-Wilk test to determine whether the Legionella load was distributed normally, the Wilcoxon rank sum test to compare the air temperatures (average and range) of the negative and positive samples for Legionella detection, and the multivariate analysis (Poisson regression) to compare the Legionella load with the water sample temperature, average air temperature, and temperature range on the day of sampling. The Wilcoxon test for paired samples was used to compare legionellosis cases between the warmer and colder months. Results: Overall, 13,044 water samples were analyzed for Legionella and 460 cases of legionellosis were notified. Legionella was isolated in 20.1% of the samples examined. The difference in the air temperature between negative samples and positive samples was statistically significant (p-value < 0.0001): on days when water samples tested positive for Legionella a higher temperature range was observed than on days when water samples tested negative (p-value = 0.004). Poisson regression showed a direct correlation between Legionella load, water temperature, and average air temperature. The incidence of legionellosis cases in warmer months was higher than in colder months (p-value = 0.03). Conclusions: Our study highlights a significant increase in the load of Legionella in the Apulian water network, and an association between warmer temperatures and legionellosis incidence. In our opinion, further investigations are needed in different contexts and territories to characterize the epidemiology of legionellosis, and to explain its extreme variability in different geographical areas and how these data may be influenced by different risk factors.

Burden of disease from contaminated drinking water in countries with high access to safely managed water: A systematic review.

The vast majority of residents of high-income countries (≥90%) reportedly have high access to safely managed drinking water. Owing perhaps to the widely held perception of near universal access to high-quality water services in these countries, the burden of waterborne disease in these contexts is understudied. This systematic review aimed to: identify population-scale estimates of waterborne disease in countries with high access to safely managed drinking water, compare methods to quantify disease burden, and identify gaps in available burden estimates. We conducted a systematic review of population-scale disease burden estimates attributed to drinking water in countries where ≥90% of the population has access to safely managed drinking water per official United Nations monitoring. We identified 24 studies reporting estimates for disease burden attributable to microbial contaminants. Across these studies, the median burden of gastrointestinal illness risks attributed to drinking water was ∼2,720 annual cases per 100,000 population. Beyond exposure to infectious agents, we identified 10 studies reporting disease burden-predominantly, cancer risks-associated with chemical contaminants. Across these studies, the median excess cancer cases attributable to drinking water was 1.2 annual cancer cases per 100,000 population. These median estimates slightly exceed WHO-recommended normative targets for disease burden attributable to drinking water and these results highlight that there remains important preventable disease burden in these contexts, particularly among marginalized populations. However, the available literature was scant and limited in geographic scope, disease outcomes, range of microbial and chemical contaminants, and inclusion of subpopulations (rural, low-income communities; Indigenous or Aboriginal peoples; and populations marginalized due to discrimination by race, ethnicity, or socioeconomic status) that could most benefit from water infrastructure investments. Studies quantifying drinking water-associated disease burden in countries with reportedly high access to safe drinking water, focusing on specific subpopulations lacking access to safe water supplies and promoting environmental justice, are needed.

Demographic dynamics of waterborne disease and perceived associated WASH factors in Bushenyi and Sheema districts of South-Western Uganda.

Water remains a significant player in spreading pathogens, including those associated with neglected tropical diseases. The implications of socio-demographic delineations of water quality, sanitation, and hygiene ("WASH") interventions are on the downswing. This study assessed waterborne diseases and perceived associated WASH factors in the Bushenyi and Sheema districts of South-Western Uganda. This study examines the linear relationship between WASH and identifies the association of specific demographic factors as well as their contributions/correlations to waterborne disease in the study area. A structured qualitative and quantitative data collection approach was adopted in face-to-face questionnaire-guided interviews of 200 respondents on eight surface water usage. Most participants, 65.5%, were females and had a higher score of knowledge of WASH (71%), 68% score on the improper practice of WASH, and 64% score on unsafe water quality. Low score for basic economic status was (57%), report of common diarrhoea was (47%), and a low incidence of waterborne disease outbreaks (27%). The principal component analysis (PCA) depicts the knowledge and practice of WASH to have a strong positive correlation (r = 0.84, p < 0.001; r = 0.82, p < 0.001); also economic status positively correlated with grade of water source, knowledge, and practice of WASH (correlation coefficient = 0.72; 0.99; 0.76 and p-values = 0.001; < 0.001; < 0.001 respectively). Occupation (p = 0.0001, OR = 6.798) was significantly associated with knowledge and practice of WASH, while age (r = -0.21, p < 0.001) was negatively associated with knowledge and practice of WASH. The basic economic status explains why "low economic population groups" in the remote villages may not effectively implement WASH, and diarrhoea was common among the population. Diarrhoea associated with unsafe water quality and improper practice of WASH is common among the study population, and there is a low incidence of waterborne disease outbreaks. Therefore, government, stakeholders, and non-governmental organisations should work together to promote proper practice of WASH conditions to limit the occurrence of diarrhoea and prevent potential waterborne disease outbreaks.

A scoping review of waterborne and water-related disease in the Florida environment from 1999 to 2022.

Florida's environments are suitable reservoirs for many disease-causing agents. Pathogens and toxins in Florida waterways have the potential to infect mosquito vectors, animals, and human hosts. Through a scoping review of the scientific literature published between 1999 and 2022, we examined the presence of water-related pathogens, toxins, and toxin-producers in the Florida environment and the potential risk factors for human exposure. Nineteen databases were searched using keywords relating to the waterborne, water-based toxins, and water-related vector-borne diseases which are reportable to the Florida Department of Health. Of the 10,439 results, 84 titles were included in the final qualitative analysis. The resulting titles included environmental samples of water, mosquitoes, algae, sand, soil/sediment, air, food, biofilm, and other media. Many of the waterborne, water-related vector-borne, and water-based toxins and toxin-producers of public health and veterinary importance from our search were found to be present in Florida environments. Interactions with Florida waterways can expose humans and animals to disease and toxins due to nearby human and/or animal activity, proximal animal or human waste, failing or inadequate water and/or sanitation, weather patterns, environmental events, and seasonality, contaminated food items, preference of agent for environmental media, high-risk populations, urban development and population movement, and unregulated and unsafe environmental activities. A One Health approach will be imperative to maintaining healthy waterways and shared environments throughout the state to protect the health of humans, animals, and our ecosystems.

Evaluation of physicochemical and microbiological parameters, and their correlation in Himalayan Spring Water Systems: A case study of District Kulgam of Kashmir Valley, India, Western Himalaya.

Total coliforms, E. coli, and fecal streptococci are the important indicators linked to the human health. This study investigated presence of these indicator bacteria in the Himalayan springs at various locations in the district Kulgam of Kashmir valley. A total of 30 spring water samples were collected from rural, urban, and forest areas during post-melting season 2021 and pre-melting season 2022. The springs in the area originate from the alluvium deposit, Karewa, and hard rock formations. The physicochemical parameters were found within the acceptable limits. However, nitrate and phosphate were found above the permissible limit at few sites, thus indicating the presence of anthropogenic activities in the area. Majority of the samples during both the seasons were found highly loaded with total coliforms with maximum limit of greater than 180 MPN/100 ml. E. coli and fecal streptococci were found in the range of less than 1 to more than 180 MPN/100 ml. The results of Pearson correlation of physicochemical parameters with indicator bacteria showed that chemical oxygen demand, rainfall, spring discharge, nitrate, and phosphate are the main factors affecting the concentration of indicator bacteria in the spring water at each site. Principal component analysis showed the most influencing factors of water quality in most of the spring sites are total coliforms, E. coli, fecal streptococci, rainfall, discharge, and chemical oxygen demand. The results of this study showed that the spring water is unfit for drinking purpose because of high concentration of fecal indicator bacteria.

Interrupted time series segmented regression analysis for detecting waterborne disease outbreaks by syndromic surveillance.

Introduction: Pathogens can enter the drinking water supply and cause gastroenteritis outbreaks. Such events can affect many people in a short time, making them a high risk for public health. In Australia, the Victoria State Government Department of Health is deploying a syndromic surveillance system for drinking water contamination events. We assessed the utility of segmented regression models for detecting such events and determined the number of excess presentations needed for such methods to signal a detection. Methods: The study involved an interrupted time series study of a past lapse in water treatment. The baseline period comprised the four weeks before the minimum incubation period of suspected pathogens, set at two days post-event. The surveillance period comprised the week after. We used segmented linear regression to compare the count of gastroenteritis presentations to public hospital emergency departments (EDs) between the surveillance and baseline periods. We then simulated events resulting in varying excess presentations. These were superimposed onto the ED data over fifty different dates across 2020. Using the same regression, we calculated the detection probability at p < 0.05 for each outbreak size. Results: In the retrospective analysis, there was strong evidence for an increase in presentations shortly after the event. In the simulations, with no excess presentations (i.e., with the ED data as is) the models signalled 8% probability of detection. The models returned 50% probability of detection with 28 excess presentations and 100% probability of detection with 78 excess presentations. Conclusions: The transient increase in presentations after the event may be attributed to microbiological hazards or increased health-seeking behaviour following the issuing of boil water advisories. The simulations demonstrated the ability for segmented regressions to signal a detection, even without a large excess in presentations. The approach also demonstrated high specificity and should be considered for informing Victoria's syndromic surveillance system.

Machine learning based efficient prediction of positive cases of waterborne diseases.

BACKGROUND: Water quality has been compromised and endangered by different contaminants due to Pakistan's rapid population development, which has resulted in a dramatic rise in waterborne infections and afflicted many regions of Pakistan. Because of this, modeling and predicting waterborne diseases has become a hot topic for researchers and is very important for controlling waterborne disease pollution. METHODS: In our study, first, we collected typhoid and malaria patient data for the years 2017-2020 from Ayub Medical Hospital. The collected data set has seven important input features. In the current study, different ML models were first trained and tested on the current study dataset using the tenfold cross-validation method. Second, we investigated the importance of input features in waterborne disease-positive case detection. The experiment results showed that Random Forest correctly predicted malaria-positive cases 60% of the time and typhoid-positive cases 77% of the time, which is better than other machine-learning models. In this research, we have also investigated the input features that are more important in the prediction and will help analyze positive cases of waterborne disease. The random forest feature selection technique has been used, and experimental results have shown that age, history, and test results play an important role in predicting waterborne disease-positive cases. In the end, we concluded that this interesting study could help health departments in different areas reduce the number of people who get sick from the water.

(Mis)perception and Use of Unsterile Water in Home Medical Devices, PN View 360+ Survey, United States, August 20211.

Tap water is not sterile, and its use in home medical devices can result in infections from waterborne pathogens. However, many participants in a recent survey in the United States said tap water could safely be used for home medical devices. These results can inform communication materials to reduce the high consequence of infections.

The Clinical Profile of Children With Hepatitis A Infection: An Observational Hospital-Based Study.

INTRODUCTION:  Hepatitis A is a frequent form of hepatitis, especially in children. The changing epidemiology of the disease signifies the need for descriptive data concerning the clinical presentation and outcome of hepatitis A in children. The present study describes the clinical and biochemical profile of children with hepatitis A infection from a tertiary care center in the Aurangabad district of Maharashtra in Western India. METHODS:  One hundred patients between one and 18 years of age, presenting with symptoms/signs such as nausea, anorexia, vomiting, jaundice, abdominal pain, tender hepatomegaly, bleeding manifestations, or encephalopathy, were enrolled for the study. Serologically confirmed cases by detecting immunoglobulin M (IgM) antibodies against hepatitis A virus (HAV) were enrolled in the study. A detailed case proforma noted the clinical features and details such as age, gender, area, water supply, socioeconomic status, season, and biochemical parameters. RESULTS:  Most patients (45%) were among the age group of one to five years. Fever was reported in 96 (96%) patients, abdominal pain in 78 (78%) patients, dark-colored urine in 65 (65%) patients, vomiting in 47 (47%) patients, and anorexia in 63 (63%) patients. Icterus was found in 80 (80%) patients and hepatomegaly in 74 (74%) patients. In 61 (61%) patients, serum total bilirubin level on the first day was 1-4 mg/dL. Sixty-five (65%) patients were using tap water as the water source, and the maximum number of patients (43%) came in August. Most patients belonged to the class IV group (61%) as per the modified Kuppuswamy classification. CONCLUSIONS:  Most patients were 10 years or below, presenting predominantly with fever, abdominal pain, dark-colored urine, vomiting, and anorexia. Icterus and hepatomegaly were found in three-fourths or more of the patients. Around monsoon (June to September), there was the highest frequency of cases, and the socioeconomic status of most of the patients was within lower or upper-lower categories.

Infectious Diseases Associated with Hydrometeorological Hazards in Europe: Disaster Risk Reduction in the Context of the Climate Crisis and the Ongoing COVID-19 Pandemic.

Hydrometeorological hazards comprise a wide range of events, mainly floods, storms, droughts, and temperature extremes. Floods account for the majority of the related disasters in both developed and developing countries. Flooding alters the natural balance of the environment and frequently establish a favorable habitat for pathogens and vectors to thrive. Diseases caused by pathogens that require vehicle transmission from host to host (waterborne) or a host/vector as part of their life cycle (vector-borne) are those most likely to be affected by flooding. Considering the most notable recent destructive floods events of July 2021 that affected several Central Europe countries, we conducted a systematic literature review in order to identify documented sporadic cases and outbreaks of infectious diseases in humans in Europe, where hydrometeorological hazards, mainly floods, were thought to have been involved. The occurrence of water-, rodent-, and vector-borne diseases in several European countries is highlighted, as flooding and the harsh post-flood conditions favor their emergence and transmission. In this context, strategies for prevention and management of infectious disease outbreaks in flood-prone and flood-affected areas are also proposed and comprise pre- and post-flood prevention measures, pre- and post-outbreak prevention measures, as well as mitigation actions when an infectious disease outbreak finally occurs. Emphasis is also placed on the collision of floods, flood-related infectious disease outbreaks, and the evolving COVID-19 pandemic, which may result in unprecedented multi-hazard conditions and requires a multi-hazard approach for the effective disaster management and risk reduction.

Solar disinfection - An appropriate water treatment method to inactivate faecal bacteria in cold climates.

Solar disinfection (SODIS) is an inexpensive drinking water treatment method applied in tropical and sub-tropical low-income countries. However, it has been unclear whether it functions adequately also in colder climates. To investigate this issue, SODIS experiments were performed in the humid continental climate of Finland by exposing faecally contaminated drinking water to natural solar radiation at different water temperatures (8-23 °C) and UV intensities (12-19 W/m2) in polyethylene (PE) bags. To establish an adequate benchmark, SODIS experiments with the same experimental design were additionally conducted in the Mediterranean climate of Spain in typical conditions of SODIS application (~39 °C and 42 W/m2). Out of all experiments, the highest coliform and enterococci inactivation efficiencies in terms of lowest required doses for 4-log disinfection (25 Wh/m2 and 60 Wh/m2, respectively) were obtained in humid continental climate at the lowest studied mean water temperature (8-11 °C). Despite the low mean UV irradiance (~19 Wh/m2), 4-log disinfection of coliforms and enterococci were also reached fast in these conditions (1 h 27 min and 3 h 18 min, respectively). Overall, the doses required for disinfection increased as the water temperatures and UV intensities of the experiments rose. Disinfection of 4-logs (> 99.99%) of both bacteria was reached in all SODIS experiments within 6 h, suggesting SODIS could be a sufficient household water treatment method also in colder climates, unlike previously thought. The effects of different water temperatures on bacterial inactivation were also tested in the absence of sunlight. Together the obtained results indicate that while water temperatures below or close to the optima of coliforms and enterococci (~10 °C) alone do not cause inactivation, these temperatures may enhance SODIS performance. This phenomenon is attributed to slower bacterial metabolism and hence slower photorepair induced by the low water temperature.

Waterborne protozoan outbreaks: An update on the global, regional, and national prevalence from 2017 to 2020 and sources of contamination.

The aim of this review is to identify the worldwide trend of waterborne protozoan outbreaks and how it varies between geographic regions during the period from 2017 to 2020. Data about waterborne protozoan outbreaks were gathered and stratified by continent, country, water source, and protozoan species associated with the outbreak. The highest prevalence of waterborne protozoan outbreaks was reported in developed countries. Out of 251 outbreaks reported worldwide during the studied period, 141, 51 and 24 outbreaks were recorded in the USA, UK, and New Zealand, respectively. These outbreaks were mainly associated with Cryptosporidium (192 outbreaks) and Giardia (48 outbreaks). Cyclospora cayetanensis, Dientamoebafragilis and Toxoplasma gondii were associated with 7 outbreaks. One outbreak was associated with each of Blastocystis hominis, Entamoeba histolytica, Microsporidia or Naegleria fowleri. This data suggests large discrepancies in the number of outbreaks reported between geographic regions, with most outbreaks recorded in developed countries. Differences in the prevalence of outbreaks between countries are likely attributed to the availability of diagnostic capabilities and surveillance programs to monitor water contamination with pathogenic protozoa. More attention and concerted efforts are required to improve water safety and to alleviate the impact of waterborne protozoan infections. Appropriate surveillance of water contamination with protozoa can enable public health officials to identify source of contamination and implement the necessary measures to limit transmission and prevent outbreaks.

Implementation of a national waterborne disease outbreak surveillance system: overview and preliminary results, France, 2010 to 2019.

BackgroundWaterborne disease outbreaks (WBDO) associated with tap water consumption are probably underestimated in France.AimIn order to improve their detection, Santé publique France launched a surveillance system in 2019, based on the periodical analysis of health insurance data for medicalised acute gastroenteritis (mAGE).MethodsSpatio-temporal cluster detection methods were applied to mAGE cases to prioritise clusters for further investigation. These investigations determined the plausibility that infection is of waterborne origin and the strength of association.ResultsBetween January 2010 and December 2019, 3,323 priority clusters were detected (53,878 excess mAGE cases). They involved 3,717 drinking water supply zones (WSZ), 15.4% of all French WSZ. One third of these WSZ (33.4%; n = 1,242 WSZ) were linked to repeated clusters. Moreover, our system detected 79% of WBDO voluntarily notified to health authorities.ConclusionEnvironmental investigations of detected clusters are necessary to determine the plausibility that infection is of waterborne origin. Consequently, they contribute to identifying which WSZ are linked to clusters and for which specific actions are needed to avoid future outbreaks. The surveillance system incorporates three priority elements: linking environmental investigations with water safety plan management, promoting the systematic use of rainfall data to assess waterborne origin, and focusing on repeat clusters. In the absence of an alternative clear hypothesis, the occurrence of a mAGE cluster in a territory completely matching a distribution zone indicates a high plausibility of water origin.

Twenty years of waterborne and related disease reports in Florida, USA.

Florida represents a unique challenge for preventing and responding to infectious disease associated with water. This study cataloged the prevalence of reportable waterborne and water-related disease within Florida residents over the last twenty years and identified relationships between confirmed cases by location and additional risk factors. Data was collected through FLHealthCHARTS for confirmed cases between January 1, 1999 and December 31, 2019. Case records were compiled and analyzed by year, county, pathogen name and disease category, patient age, and where the infection was acquired. During this time, 218,707 cases of water-related disease were recorded with 214,745 due to waterborne disease, 3255 cases of water-related vector-borne disease, and 707 cases caused by a water-based toxin. Children aged 0-4 and the elderly demonstrated a higher proportion of waterborne disease while 45-49 year olds had increased rates of water-based toxins and water-related vector-borne disease. Most cases were reported in the southeast region. Across the state, opportunities for water contact have led to high rates of water-related infectious disease. Public health initiatives and response efforts should target the pathogens of greatest impact for each region, largely zoonotic waterborne diseases, using a One Health approach.

Reliability of thermal desalination (solar stills) for water/wastewater treatment in light of COVID-19 (novel coronavirus "SARS-CoV-2") pandemic: What should consider?

The COVID-19 pandemic disturbed the world from the beginning of 2020. The high excessive number of patients and the presence of the SARS-CoV-2 in human excreta and urine even after the infected person's respiratory tests were negative, results in a heavy load of viral in various water bodies and mostly untreated wastewaters. In the present study, the reliability of using small-scale solar thermal desalination systems (solar stills) during a situation like the COVID-19 pandemic is discussed. Pollution of water bodies through the SARS-CoV-2 via numerous routes increases the risk of contaminating the feed water and subsequently the whole structure of solar stills. Since the transmission of pathogens (particle size: 0.5-3 µm) via droplets of water in solar still is reported before, transmitting of SARS-CoV-2 via droplets of water which multiple times smaller (particle size: 60-140 nm) than those pathogens is a concern. The most important issue which must be highlighted is that solar stills worked at low-temperature while the viability and survival of the SARS-CoV-2 in various water matrices in the temperature range (4-37 °C) for several days is reported. In this regard, using solar stills during the COVID-19 pandemic need further consideration by all researchers and people around the world.

Trends in recent waterborne and foodborne disease outbreaks in South Korea, 2015-2019.

OBJECTIVE: This study analyzed trends in foodborne and waterborne diseases in South Korea between 2015 and 2019. METHODS: The data consisted of information on outbreaks of waterborne and foodborne infectious diseases reported through the Korea Centers for Disease Control and Prevention (KCDC) system. We analyzed the trends and epidemiological aspects of outbreaks by month, place of occurrence, and causative pathogens in this observational study. RESULTS: The number of outbreaks has steadily increased over the last 5 years, but the number of cases per outbreak has followed a decreasing trend. Incidence at daycare centers and preschools has been steadily increasing over consecutive years. CONCLUSION: The steady number of patients and decreasing number of cases per outbreak, even as the number of outbreaks has been increasing, suggest that the KCDC's professional management system is operating effectively. It is necessary to continue improving the objectivity and efficiency of the management system and to carefully examine the increasing number of outbreaks in smaller-scale group catering facilities, such as daycare centers and preschools. Outbreaks can be prevented by closely examining those caused by unidentified pathogens and group outbreaks caused by other diseases, identifying problems, and supplementing the management system.

Prevalence of emerging torque teno virus (TTV) in drinking water, natural waters and wastewater networks (DWNWWS): A systematic review and meta-analysis of the viral pollution marker of faecal and anthropocentric contaminations.

The emerging torque teno virus (TTV) has been identified as a biohazard marker of anthropocentric pollution and contamination in drinking water, natural water and wastewater systems (DWNWWS). Therefore, this study aimed at assessing prevalence of TTV in DWNWWS. The study systematically identified and meta-analyzed published studies on TTV prevalence in DWNWWS hosted in Dimensions, Google Scholar, PubMed, Web of Science, and Scopus databases using a random-effects model and mixed-effects meta-regression model for sensitivity analysis. Furthermore, the meta-analysis was stratified to estimate water type-specific TTV prevalence. The study found a total of 58 articles, of which 13 articles subdivided into 31 studies with 374 TTV positive cases and 862 total sample sizes were systematically reviewed and meta-analyzed. The pooled prevalence of TTV in DWNWWS was 37.18% (95%CI: 23.76-55.55%). Prevalence of TTV was significantly different across water types and it was 56.67% (95%CI: 36.94-75.46%) in wastewater, 26.72% (95%CI: 6.87-52.56%) in river water, and 17.17% (95%CI: 0.54-45.39%) in drinking water. TTV incidence in seawater and groundwater was 0% and 25.0% respectively. Funnel plots constructed and associated statistics of rank correlation test and Egger's regression test in this study, show lack of publication bias in the pooled prevalence of TTV in DWNWWS. Although, sample type (QM(df = 1) = 6.9656, p = 0.0083) and concentration methods (QM(df = 1) = 3.8055, p = 0.0511) significantly moderated and accounted for 15.39% and 6.00% of heterogeneity in the prevalence of TTV in DWNWWS respectively. In conclusion, research focus/monitoring activities on TTV is generally inadequate and potential risk of TTV in DWNWWS is underappreciated in most nations; the analyzed studies were from 7 countries (USA, Japan, Italy, Iran, Germany, Egypt, and Brazil). Finally, inefficient concentration method severely influences the prevalence of TTV in DWNWWS and could give rise to underestimation of TTV and mar TTV-based source-tracking of anthropogenic pollutions.

Hidden Diversity within Common Protozoan Parasites as Revealed by a Novel Genomotyping Scheme.

Giardia duodenalis (syn. Giardia lamblia, Giardia intestinalis) is the causative agent of giardiasis, one of the most common diarrheal infections in humans. Evolutionary relationships among G. duodenalis genotypes (or subtypes) of assemblage B, one of two genetic assemblages causing the majority of human infections, remain unclear due to poor phylogenetic resolution of current typing methods. In this study, we devised a methodology to identify new markers for a streamlined multilocus sequence typing (MLST) scheme based on comparisons of all core genes against the phylogeny of whole-genome sequences (WGS). Our analysis identified three markers with resolution comparable to that of WGS data. Using newly designed PCR primers for our novel MLST loci, we typed an additional 68 strains of assemblage B. Analyses of these strains and previously determined genome sequences showed that genomes of this assemblage can be assigned to 16 clonal complexes, each with unique gene content that is apparently tuned to differential virulence and ecology. Obtaining new genomes of Giardia spp. and other eukaryotic microbial pathogens remains challenging due to difficulties in culturing the parasites in the laboratory. Hence, the methods described here are expected to be widely applicable to other pathogens of interest and advance our understanding of their ecology and evolution.IMPORTANCEGiardia duodenalis assemblage B is a major waterborne pathogen and the most commonly identified genotype causing human giardiasis worldwide. The lack of morphological characters for classification requires the use of molecular techniques for strain differentiation; however, the absence of scalable and affordable next-generation sequencing (NGS)-based typing methods has prevented meaningful advancements in high-resolution molecular typing for further understanding of the evolution and epidemiology of assemblage B. Prior studies have reported high sequence diversity but low phylogenetic resolution at standard loci in assemblage B, highlighting the necessity of identifying new markers for accurate and robust molecular typing. Data from comparative analyses of available genomes in this study identified three loci that together form a novel high-resolution typing scheme with high concordance to whole-genome-based phylogenomics and which should aid in future public health endeavors related to this parasite. In addition, data from newly characterized strains suggest evidence of biogeographic and ecologic endemism.