Waterborne Outbreaks Research Articles

Dead-End Ultrafiltration and DNA-Based Methods for Detection of Cyclospora cayetanensis in Agricultural Water.

Cyclospora cayetanensis is a protozoan parasite that causes foodborne and waterborne diarrheal illness outbreaks worldwide. Most of these outbreaks are associated with the consumption of fresh produce. Sensitive and specific methods to detect C. cayetanensis in agricultural water are needed to identify the parasite in agricultural water used to irrigate crops that have been implicated in outbreaks. In this study, a method to detect C. cayetanensis in water by combining dead-end ultrafiltration (DEUF) with sensitive and specific molecular detection was developed and evaluated. Triplicates of 10-liter agricultural water samples were seeded with 200, 100, 25, 12, and 6 C. cayetanensis oocysts. Surface water samples were also collected in the Mid-Atlantic region. All water samples were processed by DEUF and backflushed from the ultrafilters. DNA was extracted from concentrated samples and analyzed by quantitative PCR (qPCR) targeting the C. cayetanensis 18S rRNA gene. All water samples seeded with 12, 25, 100, and 200 oocysts were positive, and all unseeded samples were negative. Samples seeded with 6 oocysts had a detection rate of 66.6% (8/12). The method was also able to detect C. cayetanensis isolates in surface water samples from different locations of the Chesapeake and Ohio Canal (C&O Canal) in Maryland. This approach could consistently detect C. cayetanensis DNA in 10-liter agricultural water samples contaminated with low levels of oocysts, equivalent to the levels that may be found in naturally incurred environmental water sources. Our data demonstrate the robustness of the method as a useful tool to detect C. cayetanensis from environmental sources.IMPORTANCECyclospora cayetanensis is a protozoan parasite that causes foodborne and waterborne outbreaks of diarrheal illness worldwide. These foodborne outbreaks associated with the consumption of fresh produce and agricultural water could play a role in the contamination process. In this study, a method to detect C. cayetanensis in agricultural water by combining a robust filtration system with sensitive and specific molecular detection was developed and validated by the FDA. The results showed that this approach could consistently detect low levels of C. cayetanensis contamination in 10 liters of agricultural water, corresponding to the levels that may be found in naturally occurring environmental water sources. The method was also able to detect C. cayetanensis in surface water samples from a specific location in the Mid-Atlantic region. Our data demonstrate the robustness of the method to detect C. cayetanensis in agricultural water samples, which could be very useful to identify environmental sources of contamination.

Potential Early Identification of a Large Campylobacter Outbreak Using Alternative Surveillance Data Sources: Autoregressive Modelling and Spatiotemporal Clustering.

BackgroundOver one-third of the population of Havelock North, New Zealand, approximately 5500 people, were estimated to have been affected by campylobacteriosis in a large waterborne outbreak. Cases reported through the notifiable disease surveillance system (notified case reports) are inevitably delayed by several days, resulting in slowed outbreak recognition and delayed control measures. Early outbreak detection and magnitude prediction are critical to outbreak control. It is therefore important to consider alternative surveillance data sources and evaluate their potential for recognizing outbreaks at the earliest possible time.ObjectiveThe first objective of this study is to compare and validate the selection of alternative data sources (general practice consultations, consumer helpline, Google Trends, Twitter microblogs, and school absenteeism) for their temporal predictive strength for Campylobacter cases during the Havelock North outbreak. The second objective is to examine spatiotemporal clustering of data from alternative sources to assess the size and geographic extent of the outbreak and to support efforts to attribute its source.MethodsWe combined measures derived from alternative data sources during the 2016 Havelock North campylobacteriosis outbreak with notified case report counts to predict suspected daily Campylobacter case counts up to 5 days before cases reported in the disease surveillance system. Spatiotemporal clustering of the data was analyzed using Local Moran’s I statistics to investigate the extent of the outbreak in both space and time within the affected area.ResultsModels that combined consumer helpline data with autoregressive notified case counts had the best out-of-sample predictive accuracy for 1 and 2 days ahead of notified case reports. Models using Google Trends and Twitter typically performed the best 3 and 4 days before case notifications. Spatiotemporal clusters showed spikes in school absenteeism and consumer helpline inquiries that preceded the notified cases in the city primarily affected by the outbreak.ConclusionsAlternative data sources can provide earlier indications of a large gastroenteritis outbreak compared with conventional case notifications. Spatiotemporal analysis can assist in refining the geographical focus of an outbreak and can potentially support public health source attribution efforts. Further work is required to assess the location of such surveillance data sources and methods in routine public health practice.

Norovirus foodborne outbreak in an agritourism: causes, development and legal consequences

Abstract Background Norovirus is the main causative agent of viral acute gastroenteritis. It is easily transmitted and frequently causes foodborne and waterborne outbreaks. The Food Hygiene Service of ASL 2 Abruzzo received notification of gastrointestinal illness in 33 customers who attended a lunch at an agritourism on 28 July 2019. Methods The investigation started immediately. The event was reported to the Judicial Authority and food preparation was suspended. Stool specimens and rectal swabs were collected from 18 guests and 2 food handlers and tested. A questionnaire survey was given to the customers. During the inspection, the Food Hygiene Service sampled some food leftover and water from faucets. Furthermore, it found an incomplete HACCP manual. Results The 31 cases of gastrointestinal illness occurred within 12-72 hours and didn't need hospitalization. Among the affected subjects,18 were men (58.1%) with a median age of 51 years. All the biological samples collected from the subjects were positive for Norovirus GII, as revealed by Real Time-PCR. The two food handlers resulted positive for Norovirus GII, but they were asymptomatic. They were tested up to 3 weeks after the outbreak and their feces remained positive. Water and food samples resulted negative, except for raw ham's outer surface, that resulted positive for Norovirus GII. The contamination probably occurred during food preparation. Discussion This outbreak was related to food cross-contamination by infected food handlers, likely caused by a failure in application of both personal and food hygiene measures prescribed in HACCP plan. Food preparation restarted on 12 September 2019, but infected food handlers were dismissed until they were positive. The Judicial Authority will file a lawsuit against the food operator business that could lead to imprisonment or fines. Key messages Norovirus outbreaks are recognized as a public health concern causing a high number of cases and serious health consequences in children and the elderly. HACCP manual must be customized for each food business and integrally applied by food handlers in order to attain a higher standard of food safety for prevention of foodborne illness.

Evaluation of three different filters and two methods for recovering viruses from drinking water

Among the enteric viruses implicated in waterborne outbreaks, human norovirus and hepatitis A virus (HAV) are a serious public health issue. Most foodborne viruses are difficult or currently unlikely to cultivate. Because of the lack of a cell culture method, real-time reverse transcriptase PCR is commonly used for the detection of norovirus in foodstuffs and environmental samples. Due to low infectious doses in humans and low virus concentration in water sample, filter adsorption methods were used for concentrating viruses from water. The ISO (Anonymous, ISO 15216-1, 2017) describes standardized molecular methods for detecting HAV and norovirus in bottled water. This method includes a two-step procedure: concentrating the virus using a microporous electropositive filter (47 mm diameter, 0.45 μm pore size) then molecular detection. The Zetapor filter, which had a charged membrane with a pore size of 0.45 μm, was commonly used in the past to concentrate viruses from water or from salad leaves following virus elution. But, unfortunately, the Zetapor filter is no longer marketed and it is therefore necessary to assess an alternative filter. The aim of this study was to compare the ability of two electropositive filters with a pore size of 0.45 μm or 0.22 μm and one uncharged filter (0.45 μm) to recover norovirus and HAV from two different types of drinking water (bottled water and tap water) with the adsorption-elution method proposed by ISO (Anonymous, ISO 15216-1, 2017) (method A) and with direct viral extraction using filters (method B). The mean extraction yields for norovirus and HAV calculated with RNA extracts ranged from 0.2 % – 4.81 % with method A and from 5.05 % – 53.58 % with method B, and did not differ significantly between the two types of drinking water tested. For method B, the mean extraction yields for HAV and norovirus were evaluated according to results from the three filters used. The recovery rate of HAV and norovirus ranged between 3.47 % and 62.41 % with the 0.45 μm electropositive filter and were higher than the other filters. The 0.45 μm electropositive filter could be used to concentrate viruses for routine viral monitoring of drinking water for researchers who want to adopt the method in their lab routine.

Environmental surveillance of human enteric viruses in wastewaters, groundwater, surface water and sediments of Campania Region

Enteric viruses represent a public health risk since they are involved in foodborne and waterborne outbreaks. The aim of this study was to investigate the circulation of select human enteric viruses — hepatitis A virus (HAV), noroviruses (NoVGI and NoVGII), adenovirus (AdV), rotavirus (RV), astrovirus (AsV), sapovirus (SaV) and aichivirus (AiV) – in wastewater and in environmental samples (groundwater, surface water and sediments) of Campania Region, southern Italy, with the goal of evaluating their circulation in the environment and to characterize the circulating strains by phylogenetic analysis. A total of 199 water and sediment samples were collected from rivers, dams, wells and wastewater treatment plants (WWTPs) in all provinces of the Campania Region and analysed by real-time qPCR for the detection of viruses, after a concentration step with organic flocculation. This study provides information on the qualitative and quantitative spread of human enteric viruses in the environment and their potential health risk. In our samples all the viral families were detected, with different prevalence. Among the investigated viruses, RV was the most prevalent and concentrated virus in surface water and sediments, with AsV being prevalent and concentrated in wastewater. The prevalence of viral pathogens was not influenced by season for almost all enteric viruses, except for NoVGII in WWTPs. Within the WWTPs, a significant reduction in the average concentration levels was observed for all viral targets from the influent to the effluent except for the HAV and AiV. The results of our study confirmed the importance of environmental surveillance that can represent a key tool for pollution control and human risk exposure.

Hepatitis E virus genotype 1f outbreak in Bangladesh, 2018

Hepatitis E virus (HEV) infection is a significant public health issue in many developing countries, causing waterborne outbreaks as well as sporadic hepatitis. We report here an outbreak of HEV genotype 1f infection during Apr-May 2018 among persons living at Halisohor, a low land of southern part of Chottogram District of Bangladesh. A total of 933 patients were admitted in Combined Military Hospital (CMH) Chottogram with symptoms of acute hepatitis. Among them 550 patients were tested by ELISA for HEV specific IgM and all were positive. Genotyping, sequencing and phylogenetic analysis based on ORF 2 region revealed that the outbreak was caused by genotype 1f and the strains were closely related to the previously reported HEV strains that caused outbreak in Bangladesh in 2010. The current outbreak was most likely linked with water supply as fecal contamination in water was evident and could be prevented by ensuring access to safe drinking water.
 Bangladesh J Microbiol, Volume 37 Number 1 June 2020, pp 35-37

Waterborne outbreaks in Iceland - analysis of scale and causes

Clean drinking water is essential for public health. The cause of waterborne outbreaks is most often faecal contamination of water from animals or humans. The objective of this resarch was to collect available information on waterborne outbreaks in Iceland for the twenty year period, 1998-2017. Incident of faecal and pathogenic pollution in samples where also collected even though rarely followed by registered outbreak. Data are obtained from laboratory databases, the Directorate of Health, reports and interviews with the relevant surveillance authorities and epidemiologists. The results show that for the period investigated fifteen waterborne outbreaks were registered, all in small water supplies, many of which served transitent population, tourists and summerhouse dwellers. About 500 illnesses were confirmed and 8000 people affected. Other research have shown that around 10% of illnesses in waterborne outbreaks are registered so it can be estimated that on average 250 people have been taken ill every year because of contaminated drinking water. Analysis of monitoring water quality data show that on average 50 water supplies, or about 5% of the Icelandic registered water supplies have contained faecal matter every year. The most frequent cause of waterborne outbreak were poor design and inadequate maintainance of water intakes. It is likely that waterborne outbreaks are more numerous than are registered in official reports, especially concerning small water supplies. It also seems that the local heath authorities are often not informed of incidents of non-compliance. It is important to improve registration, information exchange between parties, epidemiological surveys and follow up of outbreaks due to drinking water to gather lessons learned. Water quality at small water supplies needs to be improved with risk-based approach and risk management.

Waterborne Outbreak of Acute Gastroenteritis Caused by Recombinant Norovirus GII.P7–GII.6 in Khabarovsk in 2019

Background: Noroviruses are common causative agents of acute gastroenteritis worldwide. Person-to-person transmission is the dominant transmission route for norovirus infection but contaminated water also often leads to outbreaks. Objectives: Our purpose was to do epidemiologic and molecular genetic analyses of waterborne norovirus infection outbreak among children in Khabarovsk in 2019. Materials and methods: Clinical and water samples were screened for the presence of norovirus RNA using real-time RT-PCR detection kit. The norovirus nucleotide sequences were determined by Sanger sequencing. The obtained sequences were subjected to a phylogenetic analysis. Results: In July 2019, 34 children developed acute gastroenteritis in Khabarovsk. The epidemiologic investigation showed that on the eve of the disease onset all patients played and bathed in a pedestrian fountain complex. A molecular genetic analysis of 18 biological samples from children with acute gastroenteritis and a water sample from the fountain revealed a recombinant norovirus GII.P7-GII.6. We established a 100.0% identity of all obtained nucleotide sequences to each other. A phylogenetic analysis of ORF2 partial sequences showed that the capsid protein of the Khabarovsk GII.P7-GII.6 strains belonged to the variant GII.6a. Conclusions: Contaminated water in the pedestrian interactive fountain complex was the most likely cause of the norovirus infection outbreak among children in Khabarovsk in 2019 associated with the lack of proper maintenance and regular disinfection measures.

Genetic diversity of norovirus genogroup I, II, IV and sapovirus in environmental water in Thailand

BackgroundEnteric caliciviruses, including noroviruses (NoVs) and sapoviruses (SaVs) are the most significant pathogens associated with waterborne and foodborne outbreaks of nonbacterial acute gastroenteritis in humans worldwide. MethodsIn this study, 126 environmental water samples collected from 6 different sources in Chiang Mai, Thailand from November 2016 to July 2018 were examined for the presence of genogroups I, II, IV (GI, GII, GIV) NoVs and SaVs by using RT-nested PCR assays, genome sequencing, and phylogenetic analysis, ResultsForty out of 126 (31.7%) water samples were positive for one or more caliciviruses throughout the years of study with high prevalence in winter. Among 126 tested specimens, 34 (27.0%), 30 (23.8%), 3 (2.4%), and 2 (1.6%) were positive for NoV GI, GII, GIV, and SaV, respectively. For NoV GI, 6 different genotypes were identified with the most predominant of GI.1 genotype (17 strains). In addition, 6 different genotypes of GII were detected with high prevalence of GII.17 (12 strains) and GII.2 (11 strains). It was interesting to note that our study reported the detection of NoV GIV for the first time in water samples in Thailand, and all were GIV.1 genotype. For SaV detection, only 2 water samples were positive for SaV GI. ConclusionsThe data revealed heterogeneity and highly dynamic distribution of NoV GI, GII, GIV, and SaV in environmental water in Chiang Mai, Thailand, during the study period of 2016–2018.

Accounting for Unexpected Risk Events in Drinking Water Systems

Unexpected risk events in drinking water systems, such as heavy rain or manure spill accidents, can cause waterborne outbreaks of gastrointestinal disease. Using a scenario-based approach, these unexpected risk events were included in a risk-based decision model aimed at evaluating risk reduction alternatives. The decision model combined quantitative microbial risk assessment and cost–benefit analysis and investigated four risk reduction alternatives. Two drinking water systems were compared using the same set of risk reduction alternatives to illustrate the effect of unexpected risk events. The first drinking water system had a high pathogen base load and a high pathogen log10 reduction in the treatment plant, whereas the second drinking water system had a low pathogen base load and a low pathogen Log10 reduction in the treatment plant. Four risk reduction alternatives were evaluated on their social profitability: (A1) installation of pumps and back-up power supply, to remove combined sewer overflows; (A2) installation of UV treatment in the drinking water treatment plant; (A3) connection of 25% of the OWTSs in the catchment area to the WWTP; and (A4) a combination of A1–A3. Including the unexpected risk events changed the probability of a positive net present value for the analysed alternatives in the decision model and the alternative that is likely to have the highest net present value. The magnitude of the effect of unexpected risk events is dependent on the local preconditions in the drinking water system. For the first drinking water system, the unexpected risk events increase risk to a lesser extent compared to the second drinking water system. The main conclusion was that it is important to include unexpected risk events in decision models for evaluating microbial risk reduction, especially in a drinking water system with a low base load and a low pathogen log10 reduction in the drinking water treatment plant.

Cryptosporidium and Giardia in surface water and drinking water: Animal sources and towards the use of a machine-learning approach as a tool for predicting contamination

Cryptosporidium and Giardia are important parasites due to their zoonotic potential and impact on human health, often causing waterborne outbreaks of disease. Detection of (oo)cysts in water matrices is challenging and few countries have legislated water monitoring for their presence. The aim of this study was to investigate the presence and origin of these parasites in different water sources in Northern Greece and identify interactions between biotic/abiotic factors in order to develop risk-assessment models. During a 2-year period, using a longitudinal, repeated sampling approach, 12 locations in 4 rivers, irrigation canals, and a water production company, were monitored for Cryptosporidium and Giardia, using standard methods. Furthermore, 254 faecal samples from animals were collected from 15 cattle and 12 sheep farms located near the water sampling points and screened for both parasites, in order to estimate their potential contribution to water contamination. River water samples were frequently contaminated with Cryptosporidium (47.1%) and Giardia (66.2%), with higher contamination rates during winter and spring. During a 5-month period, (oo)cysts were detected in drinking-water (<1/litre). Animals on all farms were infected by both parasites, with 16.7% of calves and 17.2% of lambs excreting Cryptosporidium oocysts and 41.3% of calves and 43.1% of lambs excreting Giardia cysts. The most prevalent species identified in both water and animal samples were C. parvum and G. duodenalis assemblage AII. The presence of G. duodenalis assemblage AII in drinking water and C. parvum IIaA15G2R1 in surface water highlights the potential risk of waterborne infection. No correlation was found between (oo)cyst counts and faecal-indicator bacteria. Machine-learning models that can predict contamination intensity with Cryptosporidium (75% accuracy) and Giardia (69% accuracy), combining biological, physicochemical and meteorological factors, were developed. Although these prediction accuracies may be insufficient for public health purposes, they could be useful for augmenting and informing risk-based sampling plans.

Universal Bacterial Detection Utilizing PEDOT:PSS-Based Organic Electrochemical Transistors

Bacteria are one of the most common sources of illness, responsible for a wide range of infections. Bacterial infections can be caused from a variety of sources, with thousands of deaths attributed to waterborne outbreaks alone [1]. Detection of both infectious and non-infectious bacteria is utilized to ensure commercial goods and water are safe for consumers. Current detection of bacterial contamination typically uses cell culture plates to measure the number of colony forming bacteria (CFU/ml) in a liquid media. This technique is widely used due to its high sensitivity and easy visual readout. Unfortunately, culture counting techniques is time consuming (1-3 days), requires skilled lab technicians, can be contaminated during preparation, and cannot be integrated into the desired testing media directly.To overcome these limitations, many bacterial sensors and detection techniques have been developed over the last few decades [2]. A recent sensor for bacteria detection is the organic electrochemical transistor (OECT). OECTs are polymer-based transistors that utilize ionic solutions to de-dope and re-dope a conducting channel. These devices are known for their high transconductance, bio-compatibility, low operating voltage, low cost, small size, ease of integration into measurement systems, and ability to function in aqueous environments [3]. Detection of a single bacteria is typically desired and achieved through the capture of bacteria cells onto the OECT channel area [4]. This approach allows for rapid detection of a specific pathogen with high sensitivity. However, for detecting contamination from a variety of bacteria a different approach must be used.We have investigated the OECT response to the presence of non-captured bacteria present within the OECT operating media. In this approach cells are detected both in solution and on the surface of the source-drain channel and on the gate electrode. Presence of bacteria between the gate and channel region will cause an increase in effective gate voltage, resulting in a decrease in source-drain current. Detection and characterization of (non-bacteria) whole cells has previously been reported utilizing this approach [5, 6]. In our work we have focused on the bacteria pseudomonas fluorescens (p. fluorescens) due to its size (~1µm) and potential as a water borne pathogen. P. fluorescens was cultured in LB media, diluted to three different concentrations, and used as the operating media for OECT. Concentrations of 8.7e12, 8.7e11, and 8.7e10 CFU/ml were found to shift source-drain current by 16.1, 13.8, and 12.3µA, respectively. From this data a present lower limit of detection for the sensor is estimated to be ~5.0e4 CFU/ml. 1. Craun, G.F., Statistics of waterborne outbreaks in the US (1920–1980). Waterborne diseases in the United States, 2018: p. 73-159.2. Ahmed, A., et al., Biosensors for whole-cell bacterial detection. Clinical microbiology reviews, 2014. 27(3): p. 631-646.3. Strakosas, X., M. Bongo, and R.M. Owens, The organic electrochemical transistor for biological applications. Journal of Applied Polymer Science, 2015. 132(15).4. Demuru, S., et al. Flexible Organic Electrochemical Transistor with Functionalized Inkjet-Printed Gold Gate for Bacteria Sensing. in 2019 20th International Conference on Solid-State Sensors, Actuators and Microsystems & Eurosensors XXXIII (TRANSDUCERS & EUROSENSORS XXXIII). 2019. IEEE.5. Liao, J., et al., Organic electrochemical transistor based biosensor for detecting marine diatoms in seawater medium. Sensors and Actuators B: Chemical, 2014. 203: p. 677-682.6. Ramuz, M., et al., Monitoring of cell layer coverage and differentiation with the organic electrochemical transistor. Journal of Materials Chemistry B, 2015. 3(29): p. 5971-5977. Figure 1

A comparative study of microbial contamination between public institutional and private residential bottled water dispensers

Bottled water as well as bottled water dispensers is widely used in the United Arab Emirates as a source of drinking water in residential, commercial, and institutional settings. The quality of such waters is of utmost concern as it has the potential to cause waterborne outbreaks, if (re)contaminated. Besides, bottled water dispensers could act as a source of contamination over time, if not cleaned properly on a regular basis. A cross-sectional study was conducted on 40 water samples collected from public and private bottled water dispensers in the emirates of Dubai and Sharjah. Samples were analyzed for heterotrophic plate count bacteria, fecal and total coliforms, and fungal growth. No total and fecal coliforms were detected in any of the samples. Heterotrophic plate counts (HPC) ranged between 0 and 100CFU/100ml, with an overall average of 31CFU/100ml. There was no significant difference between the HPC bacterial levels of public and private bottled water dispensers. However, a significant association (p < 0.05) was found between fungal growth and the location of the bottled water dispenser within the investigated sites. Survey outcomes also highlighted the need to spread awareness and knowledge amongst general public on basic cleanliness and hygiene practices contributing to safe drinking water and the need for stricter monitoring of public bottled water dispensers cleaning schedules.

Environmental and Adaptive Changes Necessitate a Paradigm Shift for Indicators of Fecal Contamination

ABSTRACT Changes in the occurrence, distribution, and seasonal variation of waterborne pathogens due to global climate change may increase the risk of human exposure to these microorganisms, thus heightening the need for more reliable surveillance systems. Routine monitoring of drinking water supplies and recreational waters is performed using fecal indicator microorganisms, such as Escherichia coli , Enterococcus spp., and coliphages. However, the presence and numbers of these indicators, especially E. coli and Enterococcus spp., do not correlate well with those of other pathogens, especially enteric viruses, which are a major cause of waterborne outbreaks associated with contaminated water and food, and recreational use of lakes, ponds, rivers, and estuarine waters. For that reason, there is a growing need for a surveillance system that can detect and quantify viral pathogens directly in water sources to reduce transmission of pathogens associated with fecal transmission. In this review, we present an updated overview of relevant waterborne enteric viruses that we believe should be more commonly screened to better evaluate water quality and to determine the safety of water use and reuse and of epidemiological data on viral outbreaks. We also discuss current methodologies that are available to detect and quantify these viruses in water resources. Finally, we highlight challenges associated with virus monitoring. The information presented in this review is intended to aid in the assessment of human health risks due to contact with water sources, especially since current environmental and adaptive changes may be creating the need for a paradigm shift for indicators of fecal contamination.

Waterborne outbreaks: a public health concern for rural municipalities with unchlorinated drinking water distribution systems.

The objective of this study is to describe an important waterborne outbreak of gastrointestinal illness observed in a rural municipality of Quebec. A population-based retrospective cohort study was conducted to identify risk factors associated with acute gastroenteritis. Indirect surveillance data were used to estimate the extent and the resolution of the epidemic. The cohort consisted of 140 randomly selected individuals of whom 22 met the illness case definition (15.7% attack rate). The epidemic curve was similar to the evolution of antidiarrheal products sold by the only pharmacy in town and calls made to the Health Info Line. Bivariate analysis led to identifying five risk factors of gastrointestinal illness: consumption of municipal water, contact with someone with acute gastroenteritis (within and outside of the household), contact with a child in daycare, and being less than 35years of age. Drinking municipal water had the highest risk ratio (RR = 24.31; 95% CI = 1.50-393.4). Drinking water from a private artesian well was a protective factor (RR = 0.28; 95% CI = 0.09-0.90). This study highlighted that managing the risks associated with the consumption of untreated drinking water remains an important public health challenge, particularly in small rural municipalities vulnerable to climate variability.

Hepatitis E Genotype 1 Outbreak in Jharkhand, India: A Descriptive Analysis.

A waterborne outbreak of hepatitis E virus occurred in the Jamshedpur city of Jharkhand from March 2018 to October 2018. The aim of the present study is to study the hepatitis E virus outbreak clinically, serologically and etiologically. Five hundred and eighty-four clinically and biochemically documented cases were screened for the hepatotropic viral markers (HepatitisA, B, C, and E) by the ELISA. Demographic data such as gender, age, clinical diagnosis, location, outcome and time of admission were extracted from the online hospital management system. Water samples from the affected area were tested for HEV RNA detection. Genotyping of HEV virus was carried out by sequencing and phylogenetic analysis. Hepatitis E genotype 1 was confirmed as the major etiological agent in this outbreak due to the faecal contamination of drinking water supply while establishing illegal water connections. Mixed infection of HEV-HAV (5.31%) or HEV-HBV (0.91%) was also detected in the present series of acute viral hepatitis. The study highlights the importance of screening for both enterically transmitted hepatotropic viral markers as well as the parenterally transmitted hepatotropic viral markers during the outbreaks of acute viral hepatitis.

Molecular characterization of &lt;i&gt;Cryptosporidium&lt;/i&gt; spp. from migratory ducks around Tokachi subprefecture, Hokkaido, Japan

Cryptosporidium, a waterborne protozoan parasite, has a substantial veterinary and medical impact worldwide. This parasite is more often recognized during waterborne outbreaks because of its resistance to chlorine disinfection, small size making it difficult to inactivate/eliminate through filtration, and presence in many animal species including humans. Migratory waterfowl, in addition to acting as mechanical carriers of Cryptosporidium oocysts, can also serve as natural reservoirs of infection by host-specific Cryptosporidium species. For better understanding of the extent of genetic diversity and inter-relationships among avian isolates of Cryptosporidium, 200 fecal samples of migratory ducks from the Tokachi subprefecture, Hokkaido, Japan were collected and analyzed by nested PCR (N-PCR) at the 18S rRNA gene. N-PCR revealed that 11.5% (23/200) were positive for Cryptosporidium spp. Among all samples, sequence analysis identified that 10% (20/200) were 98–100% identical to Cryptosporidium avian genotype III. On the other hand, 1.5% (3/200) were 99–100% identical to C. baileyi. This is the first molecular study reporting the prevalence of Cryptosporidium in migratory ducks in Japan. Genetic diversity among Cryptosporidium isolates from humans and birds has been reported worldwide. Nevertheless, further studies are important to assess genetic variety and to elucidate the transmission dynamics of Cryptosporidium parasites.

Outbreak-Based Giardia Dose-Response Model Using Bayesian Hierarchical Markov Chain Monte Carlo Analysis.

Giardia is a zoonotic gastrointestinal parasite responsible for a substantial global public health burden, and quantitative microbial risk assessment (QMRA) is often used to forecast and manage this burden. QMRA requires dose-response models to extrapolate available dose-response data, but the existing model for Giardia ignores valuable dose-response information, particularly data from several well-documented waterborne outbreaks of giardiasis. The current study updates Giardia dose-response modeling by synthesizing all available data from outbreaks and experimental studies using a Bayesian random effects dose-response model. For outbreaks, mean doses (D) and the degree of spatial and temporal aggregation among cysts were estimated using exposure assessment implemented via two-dimensional Monte Carlo simulation, while potential overreporting of outbreak cases was handled using published overreporting factors and censored binomial regression. Parameter estimation was by Markov chain Monte Carlo simulation and indicated that a typical exponential dose-response parameter for Giardia is r = 1.6 × 10-2 [3.7 × 10-3 , 6.2 × 10-2 ] (posterior median [95% credible interval]), while a typical morbidity ratio is m = 3.8 × 10-1 [2.3 × 10-1 , 5.5 × 10-1 ]. Corresponding (logistic-scale) variance components were σr = 5.2 × 10-1 [1.1 × 10-1 , 9.6 × 10-1 ] and σm = 9.3 × 10-1 [7.0 × 10-2 , 2.8 × 100 ], indicating substantial variation in the Giardia dose-response relationship. Compared to the existing Giardia dose-response model, the current study provides more representative estimation of uncertainty in r and novel quantification of its natural variability. Several options for incorporating variability in r (and m) into QMRA predictions are discussed, including incorporation via Monte Carlo simulation as well as evaluation of the current study's model using the approximate beta-Poisson.

Backward compatibility of whole genome sequencing data with MLVA typing using a new MLVAtype shiny application for Vibrio cholerae.

Multiple-Locus Variable Number of Tandem Repeats (VNTR) Analysis (MLVA) is widely used by laboratory-based surveillance networks for subtyping pathogens causing foodborne and water-borne disease outbreaks. However, Whole Genome Sequencing (WGS) has recently emerged as the new more powerful reference for pathogen subtyping, making a data conversion method necessary which enables the users to compare the MLVA identified by either method. The MLVAType shiny application was designed to extract MLVA profiles of Vibrio cholerae isolates from WGS data while ensuring backward compatibility with traditional MLVA typing methods. To test and validate the MLVAType algorithm, WGS-derived MLVA profiles of nineteen Vibrio cholerae isolates from Democratic Republic of the Congo (n = 9) and Uganda (n = 10) were compared to MLVA profiles generated by an in silico PCR approach and Sanger sequencing, the latter being used as the reference method. Results obtained by Sanger sequencing and MLVAType were totally concordant. However, the latter were affected by censored estimations whose percentage was inversely proportional to the k-mer parameter used during genome assembly. With a k-mer of 127, less than 15% estimation of V. cholerae VNTR was censored. Preventing censored estimation was only achievable when using a longer k-mer size (i.e. 175), which is not proposed in the SPAdes v.3.13.0 software. As NGS read lengths and qualities tend to increase with time, one may expect the increase of k-mer size in a near future. Using MLVAType application with a longer k-mer size will then efficiently retrieve MLVA profiles from WGS data while avoiding censored estimation.

The European Union One Health 2018 Zoonoses Report.

This report of the European Food Safety Authority and the European Centre for Disease Prevention and Control presents the results of zoonoses monitoring activities carried out in 2018 in 36 European countries (28 Member States (MS) and 8 non‐MS). The first and second most commonly reported zoonoses in humans were campylobacteriosis and salmonellosis, respectively. The European Union (EU) trend for confirmed human cases of these two diseases was stable during 2014–2018. The proportion of human salmonellosis cases due to Salmonella Enteritidis was at the same level in 2018 as in 2017. Of the 27 reporting MS, 16 met all Salmonella reduction targets for poultry, whereas 11 MS failed meeting at least one. The EU flock prevalence of target Salmonella serovars in breeding hens, laying hens, broilers and fattening turkeys decreased during recent years but stalled in breeding turkeys. Salmonella results from Competent Authorities for pig carcasses and for poultry tested through National Control Programmes were more frequently positive compared with food business operators. Shiga toxin‐producing Escherichia coli (STEC) infections in humans were the third most commonly reported zoonosis in the EU and increased from 2014 to 2018. Yersiniosis was the fourth most frequently reported zoonosis in humans in 2018 with a stable trend in 2014–2018. The number of reported confirmed listeriosis cases further increased in 2018, despite Listeria rarely exceeding the EU food safety limit tested in ready‐to‐eat food. In total, 5,146 food‐ and waterborne outbreaks were reported. Salmonella was the most commonly detected agent with S. Enteritidis causing one in five outbreaks. Salmonella in eggs and egg products was the highest risk agent/food pair. A large increase of human West Nile virus infections was reported in 2018. The report further updates on bovine tuberculosis, Brucella, Trichinella, Echinococcus, Toxoplasma, rabies, Coxiella burnetii (Q fever) and tularaemia.