Thermal Inactivation of Hepatitis E Virus in Pork Products Estimated with a Semiquantitative Infectivity Assay.

Hepatitis E virus genotype 3 (HEV-3) is a food-borne pathogen causative of hepatitis E infections in humans. In Europe, HEV-3 is mainly transmitted through the consumption of raw or undercooked pork. In order to determine the effectiveness of control measures that can be taken in the industry or by the consumer, it is pivotal to determine the infectivity of HEV present in pork products after thermal food-processing steps. First, we implemented a method for the detection of infectious HEV-3c and HEV-3e in a cell culture medium and in extracts from inoculated pork products. Next, we investigated the effect of the thermal inactivation of HEV by mimicking food-processing steps specific for dried sausage and liver homogenate matrices. After four weeks, HEV-inoculated dried sausage subjected to 21 °C or lower temperatures was still infectious. For the liver homogenate, the highest HEV-3c/e inactivation of the conditions tested was observed at 71 °C for five min or longer. Finally, our method was able to successfully detect and estimate viral loads of infectious HEV in naturally infected pig livers. Our data provide a basis for the future use of the quantitative microbial risk assessment of infectious HEV in pork products that are subjected to thermal food processing steps.

Epidemiology of Pathogens Listed as Potential Bioterrorism Agents, the Netherlands, 2009‒2019.

We provide incidences (cases/10 million persons) in the Netherlands during 2009-2019 for pathogens listed as potential bioterrorism agents. We included pathogens from the highest categories of the European Medicines Agency or the US Centers for Disease Control and Prevention. Notifiable diseases and recently published data were used to calculate the average annual incidence. Coxiella burnetii had the highest incidence because of a Q fever epidemic during 2007-2010. Incidence then decreased to 10.8 cases/. Pathogens with an incidence >1 were Brucella spp. (2.5 cases), Francisella tularensis (1.3 cases), and Burkholderia pseudomallei (1.1 cases). Pathogens with an incidence <1 were hemorrhagic fever viruses (0.3 cases), Clostridium botulinum (0.2 cases), and Bacillus anthracis (0.1 cases). Variola major and Yersinia pestis were absent. The generally low incidences make it unlikely that ill-meaning persons can isolate these pathogens from natural sources in the Netherlands. However, the pathogens are stored in laboratories, underscoring the need for biosecurity measures.

Biosafety and biosecurity challenges during the COVID-19 pandemic and beyond.

As the world continues to battle the SARS-CoV-2 pandemic, it is a stark reminder of the devastation biological threats can cause. In an unprecedented way the global community saw a massive surge in the demand for diagnostic capacities, which had a substantial impact on biosafety and biosecurity. Laboratories had to cope with a surge in laboratory testing capacity, while resources and training possibilities were limited. In addition, the pandemic highlighted the impact biological threats can have, thereby giving rise to new dialogue about biosecurity and new biological threats. This paper aims to highlight some of the most pressing issues regarding biosafety and biosecurity observed during the COVID-19 pandemic with special focus on low and lower middle-income countries. The authors provide lessons learned, tools and recommendations to improve future biosafety and biosecurity and increase preparedness for the next global health crisis.

Complementarity of International Instruments in the Field of Biosecurity.

The COVID-19 pandemic has demonstrated the devastating impact of infectious disease outbreaks and the threat of emerging and re-emerging dangerous pathogens, independent of their origin. Natural, accidental, and deliberate disease outbreaks all need systems in place for an effective public health response. The best known international instrument in the field of public health is the WHO International Health Regulations (2005). Although the International Health Regulations are mainly focused on natural disease outbreaks, the actions to take to comply with them also contribute to biosecurity and non-proliferation. This paper examines in case of full implementation of the International Health Regulations, what other actions states should take to comply with international biosecurity instruments, including the Biological and Toxin Weapons Convention and United Nations Security Council Resolution 1540, to effectively prevent and defend against intentional biological threats. An overview of international instruments from different disciplines regarding biosecurity is presented. Furthermore, this paper clarifies the similarities between the international biosecurity instruments and addresses the additional requirements that instruments stipulate. From a detailed comparison between the instruments it can be concluded that, to adhere to all legally-binding international biosecurity instruments, specific non-proliferation and export control measures are necessary in addition to full implementation of the International Health Regulations. Additionally, an overview of non-legally binding instruments in the field of biosecurity is presented and practical implementation examples are highlighted. Compliance with legally binding instruments can be improved by precise guidance provided by non-legally binding instruments that are clear and attuned to the situation on the ground. To improve understanding of the existing international instruments, this paper aims to provide an overview of the international legal biosecurity framework to biosecurity experts, policymakers, civil servants, and practitioners. It offers possible practical applications for the politico-legal context and accommodates the enhancement of full employment of biosecurity resources for an improved multidisciplinary capacity to prevent, detect, and respond to infectious disease outbreaks.

Dual-Use Quickscan: A Web-Based Tool to Assess the Dual-Use Potential of Life Science Research.

Research on pathogenic organisms is crucial for medical, biological and agricultural developments. However, biological agents as well as associated knowledge and techniques, can also be misused, for example for the development of biological weapons. Potential malicious use of well-intended research, referred to as "dual-use research", poses a threat to public health and the environment. There are various international resources providing frameworks to assess dual-use potential of the research concerned. However, concrete instructions for researchers on how to perform a dual-use risk assessment is largely lacking. The international need for practical dual-use monitoring and risk assessment instructions, in addition to the need to raise awareness among scientists about potential dual-use aspects of their research has been identified over the last years by the Netherlands Biosecurity Office, through consulting national and international biorisk stakeholders. We identified that Biorisk Management Advisors and researchers need a practical tool to facilitate a dual-use assessment on their specific research. Therefore, the Netherlands Biosecurity Office developed a web-based Dual-Use Quickscan (www.dualusequickscan.com), that can be used periodically by researchers working with microorganisms to assess potential dual-use risks of their research by answering a set of fifteen yes/no questions. The questions for the tool were extracted from existing international open resources, and categorized into three themes: characteristics of the biological agent, knowledge and technology about the biological agent, and consequences of misuse. The results of the Quickscan provide the researcher with an indication of the dual-use potential of the research and can be used as a basis for further discussions with a Biorisk Management Advisor. The Dual-Use Quickscan can be embedded in a broader system of biosafety and biosecurity that includes dual-use monitoring and awareness within organizations. Increased international attention to examine pathogens with pandemic potential has been enhanced by the current COVID-19 pandemic, hence monitoring of dual-use potential urgently needs to be encouraged.

Systematic approach towards establishing a National Inventory of Dangerous Pathogens.

International regulations stipulate that countries need to organize their biosafety and biosecurity systems to minimize the risk of accidental (biosafety) or malicious intentional (biosecurity) release of dangerous pathogens. International Health Regulations (IHR) benchmarks from the WHO state that even for a level of limited capacity countries need to 'Identify and document human and animal health facilities that store/maintain dangerous pathogens and toxins in the relevant sectors and health professionals responsible for them'. This study provides a stepwise, systematic approach and best practices for countries to initiate a national inventory of dangerous pathogens. With a national inventory of dangerous pathogens a country can identify and document information in a dedicated electronic database on institutes that store or maintain dangerous pathogens. The systematic approach for the implementation of a national inventory of dangerous pathogens consists of four stages; identification, preparation, implementation, and maintenance and evaluation. In the identification phase, commitment of the relevant national ministries is to be established, and a responsible government entity needs to be identified. In the preparatory phase, a list of pathogens to be incorporated in the inventory, as well as a list of institutes to include, is to be agreed upon. In the implementation phase, the institutes are contacted, and the collected data is stored safely and securely in a electronical database. Finally, in the maintenance and evaluation phase meaningful insights are derived and reported to the relevant government authorities. Also, preparations for updates and modifications are undertaken, such as modifications of pathogen lists or institute lists. The approach and database, which is available from the authors, have been tested for the implementation of a national inventory of dangerous pathogens in multiple East-African countries. A national inventory of dangerous pathogens helps countries in strengthening national biosafety and biosecurity as well as in their compliance to IHR.

Surface chemistry-dependent antiviral activity of silver nanoparticles.

The toxicity towards viruses of silver nanoparticles (AgNPs) has been reported to be dependent on several factors such as particle concentration, size, and shape. Although these factors may indeed contribute to the toxicity of AgNPs, the results presented in this work demonstrate that surface chemistry and especially surface charge is a crucial factor governing their antiviral activity. Here, this work investigated the influence of capping agents representing various surface charges ranging from negative to positive. These AgNPs were capped with citrate, polyethylene glycol (PEG), polyvinylpyrrolidone (PVP) mercaptoacetic acid (MAA) and (branched polyethyleneimine (BPEI). We show that AgNPs exhibited surface charge-dependent toxicity towards MS2 bacteriophages. Among the capping agents under investigation, BPEI capped AgNPs (Ag/BPEI) exhibited the highest reduction of MS2 resulting in ≥6 log10-units reductions, followed by 4-5 log10-units reductions with PVP and PEG capping's and 3-4 log10-units with MAA and citrate cappings. Bare nanoparticles reported a mere 1-2 log10-units reduction. Electrostatic interaction between the positively charged BPEI-coating and the negatively charged virus surface played a significant role in bringing the MS2 closer to toxic silver ions (Ag+). Further results obtained from TEM showed that Ag/BPEI nanoparticles could directly damage the structure of the MS2 bacteriophages. AgNPs and cationic capping agents' observed synergy can lead to much lower and much more efficient dosing of AgNPs for antiviral applications.

QMRA of adenovirus in drinking water at a drinking water treatment plant using UV and chlorine dioxide disinfection.

According to the Dutch Drinking Water Act of 2011, Dutch drinking water suppliers must conduct a Quantitative Microbial Risk Assessment (QMRA) for infection by the following index pathogens: enterovirus, Campylobacter, Cryptosporidium and Giardia at least once every four years in order to assess the microbial safety of drinking water. The health-based target for safe drinking water is set at less than one infection per 10 000 persons per year. At Evides Water Company, concern has arisen whether their drinking water treatment, mainly based on UV inactivation and chlorine dioxide, reduces levels of adenovirus (AdV) sufficiently. The main objective was, therefore, to conduct a QMRA for AdV. Estimates of the AdV concentrations in source water were based on enumeration of total AdV by integrated cell culture PCR (iccPCR), most probable number PCR (mpnPCR) and quantitative PCR (qPCR), and on enumeration of AdV40/41 by mpnPCR and qPCR. AdV40/41 represents a large fraction of total AdV and only a small fraction of AdV is infectious (1/1700). By comparison of literature data and plant scale data, somatic coliphages appeared a good, conservative indicator for AdV disinfection by UV irradiation. Similarly, bacteriophage MS2 appeared to be a good, conservative indicator for disinfection by chlorine dioxide. Literature data on the efficiency of chlorine dioxide disinfection were fitted with the extended HOM model. Chlorine dioxide disinfection at low initial concentrations (0.05-0.1 mg/l) was found to be the major treatment step, providing sufficient treatment on its own for compliance with the health-based target. UV disinfection of AdV at 40 mJ/cm2 or 73 mJ/cm2 was insufficient without chlorine dioxide disinfection.

The Vulnerability Scan, a Web Tool to Increase Institutional Biosecurity Resilience.

The importance of vigilance within organizations working with high-risk biological material receives increasing attention. However, an in-depth and comprehensive tool, dedicated to increase awareness of potential risks and to assess an organization's current biosecurity vulnerabilities, has not been available yet. We developed the "Biosecurity Vulnerability Scan," a web tool that identifies biosecurity gaps in an organization based on eight biosecurity pillars of good practice. Although the tool aims primarily to assist biosafety and biosecurity officers, it can also be useful to researchers working with dangerous pathogens, their principal investigators, management, or those responsible for security issues in the life sciences. Results are only stored locally and are provided in an "overview report," which includes information on relevant risks and control measures. This can support well-substantiated decision-making on strengthening biosecurity measures within a specific organization. With this article, we aim to support institutes to increase their overall security resilience and to improve institutional biosecurity in particular by providing practical recommendations. The Biosecurity Vulnerability Scan is available at www.biosecurityvulnerabilityscan.nl.

Quantitative Assessment of the Health Risk for Livestock When Animal Viruses Are Applied in Human Oncolytic Therapy: A Case Study for Seneca Valley Virus.

Some viruses cause tumor regression and can be used to treat cancer patients; these viruses are called oncolytic viruses. To assess whether oncolytic viruses from animal origin excreted by patients pose a health risk for livestock, a quantitative risk assessment (QRA) was performed to estimate the risk for the Dutch pig industry after environmental release of Seneca Valley virus (SVV). The QRA assumed SVV excretion in stool by one cancer patient on Day 1 in the Netherlands, discharge of SVV with treated wastewater into the river Meuse, downstream intake of river water for drinking water production, and consumption of this drinking water by pigs. Dose-response curves for SVV infection and clinical disease in pigs were constructed from experimental data. In the worst scenario (four log10 virus reduction by drinking water treatment and a farm with 10,000 pigs), the infection risk is less than 1% with 95% certainty. The risk of clinical disease is almost seven orders of magnitude lower. Risks may increase proportionally with the numbers of treated patients and days of virus excretion. These data indicate that application of wild-type oncolytic animal viruses may infect susceptible livestock. A QRA regarding the use of oncolytic animal virus is, therefore, highly recommended. For this, data on excretion by patients, and dose-response parameters for infection and clinical disease in livestock, should be studied.

Norovirus Outbreak Associated with Swimming in a Recreational Lake Not Influenced by External Human Fecal Sources in The Netherlands, August 2012.

Swimming in fecally contaminated recreational water may lead to gastrointestinal illness. A recreational water-associated outbreak of norovirus (NoV) infections affecting at least 100 people in The Netherlands occurred in August 2012. Questionnaire responses from patients indicated swimming in recreational lake Zeumeren as the most likely cause of illness. Most patients visited the lake during the weekend of 18⁻19 August, during which the weather was exceptionally warm (maximum temperatures 32⁻33 °C), and visitor numbers elevated. Patients, mostly children, became ill with gastroenteritis 1⁻6 days (median 2 days) after exposure. Four stool samples from patients were NoV GI positive. Subsurface sandy soil from one of the beaches where most patients swam was NoV GI positive; the water sample was negative. The epidemiological curve and the timeline of investigation based on reported symptoms demonstrate the difficulty in discovering the source in recreational water outbreaks. A NoV outbreak in a recreational lake that is not subjected to external fecal contamination sources shows the need for active communication about human shedding of viruses during and after diarrheal episodes and the advice to refrain from swimming, even a few weeks after the symptoms have resolved.

Public health risks associated with hepatitis E virus (HEV) as a food-borne pathogen.

Hepatitis E virus (HEV) is an important infection in humans in EU/EEA countries, and over the last 10 years more than 21,000 acute clinical cases with 28 fatalities have been notified with an overall 10-fold increase in reported HEV cases; the majority (80%) of cases were reported from France, Germany and the UK. However, as infection in humans is not notifiable in all Member States, and surveillance differs between countries, the number of reported cases is not comparable and the true number of cases would probably be higher. Food-borne transmission of HEV appears to be a major route in Europe; pigs and wild boars are the main source of HEV. Outbreaks and sporadic cases have been identified in immune-competent persons as well as in recognised risk groups such as those with pre-existing liver damage, immunosuppressive illness or receiving immunosuppressive treatments. The opinion reviews current methods for the detection, identification, characterisation and tracing of HEV in food-producing animals and foods, reviews literature on HEV reservoirs and food-borne pathways, examines information on the epidemiology of HEV and its occurrence and persistence in foods, and investigates possible control measures along the food chain. Presently, the only efficient control option for HEV infection from consumption of meat, liver and products derived from animal reservoirs is sufficient heat treatment. The development of validated quantitative and qualitative detection methods, including infectivity assays and consensus molecular typing protocols, is required for the development of quantitative microbial risk assessments and efficient control measures. More research on the epidemiology and control of HEV in pig herds is required in order to minimise the proportion of pigs that remain viraemic or carry high levels of virus in intestinal contents at the time of slaughter. Consumption of raw pig, wild boar and deer meat products should be avoided.

Risk assessment, risk management and risk-based monitoring following a reported accidental release of poliovirus in Belgium, September to November 2014.

On 6 September 2014, the accidental release of 10(13) infectious wild poliovirus type 3 (WPV3) particles by a vaccine production plant in Belgium was reported. WPV3 was released into the sewage system and discharged directly to a wastewater treatment plant (WWTP) and subsequently into rivers that flowed to the Western Scheldt and the North Sea. No poliovirus was detected in samples from the WWTP, surface waters, mussels or sewage from the Netherlands. Quantitative microbial risk assessment (QMRA) showed that the infection risks resulting from swimming in Belgium waters were above 50% for several days and that the infection risk by consuming shellfish harvested in the eastern part of the Western Scheldt warranted a shellfish cooking advice. We conclude that the reported release of WPV3 has neither resulted in detectable levels of poliovirus in any of the samples nor in poliovirus circulation in the Netherlands. This QMRA showed that relevant data on water flows were not readily available and that prior assumptions on dilution factors were overestimated. A QMRA should have been performed by all vaccine production facilities before starting up large-scale culture of WPV to be able to implement effective interventions when an accident happens.

Quantitative farm-to-fork risk assessment model for norovirus and hepatitis A virus in European leafy green vegetable and berry fruit supply chains.

Fresh produce that is contaminated with viruses may lead to infection and viral gastroenteritis or hepatitis when consumed raw. It is thus important to reduce virus numbers on these foods. Prevention of virus contamination in fresh produce production and processing may be more effective than treatment, as sufficient virus removal or inactivation by post-harvest treatment requires high doses that may adversely affect food quality. To date knowledge of the contribution of various potential contamination routes is lacking. A risk assessment model was developed for human norovirus, hepatitis A virus and human adenovirus in raspberry and salad vegetable supply chains to quantify contributions of potential contamination sources to the contamination of produce at retail. These models were used to estimate public health risks. Model parameterization was based on monitoring data from European supply chains and literature data. No human pathogenic viruses were found in the soft fruit supply chains; human adenovirus (hAdV) was detected, which was additionally monitored as an indicator of fecal pollution to assess the contribution of potential contamination points. Estimated risks per serving of lettuce based on the models were 3×10(-4) (6×10(-6)-5×10(-3)) for NoV infection and 3×10(-8) (7×10(-10)-3×10(-6)) for hepatitis A jaundice. The contribution to virus contamination of hand-contact was larger as compared with the contribution of irrigation, the conveyor belt or the water used for produce rinsing. In conclusion, viral contamination in the lettuce and soft fruit supply chains occurred and estimated health risks were generally low. Nevertheless, the 97.5% upper limit for the estimated NoV contamination of lettuce suggested that infection risks up to 50% per serving might occur. Our study suggests that attention to full compliance for hand hygiene will improve fresh produce safety related to virus risks most as compared to the other examined sources, given the monitoring results. This effect will be further aided by compliance with other hygiene and water quality regulations in production and processing facilities.

Wipes coated with a singlet-oxygen-producing photosensitizer are effective against human influenza virus but not against norovirus.

Transmission of enteric and respiratory viruses, including human norovirus (hNoV) and human influenza virus, may involve surfaces. In food preparation and health care settings, surfaces are cleaned with wipes; however, wiping may not efficiently reduce contamination or may even spread viruses, increasing a potential public health risk. The virucidal properties of wipes with a singlet-oxygen-generating immobilized photosensitizer (IPS) coating were compared to those of similar but uncoated wipes (non-IPS) and of commonly used viscose wipes. Wipes were spiked with hNoV GI.4 and GII.4, murine norovirus 1 (MNV-1), human adenovirus type 5 (hAdV-5), and influenza virus H1N1 to study viral persistence. We also determined residual and transferred virus proportions on steel carriers after successively wiping a contaminated and an uncontaminated steel carrier. On IPS wipes only, influenza viruses were promptly inactivated with a 5-log10 reduction. D values of infectious MNV-1 and hAdV-5 were 8.7 and 7.0 h on IPS wipes, 11.6 and 9.3 h on non-IPS wipes, and 10.2 and 8.2 h on viscose wipes, respectively. Independently of the type of wipe, dry cleaning removed, or drastically reduced, initial spot contamination of hNoV on surfaces. All wipes transferred hNoV to an uncontaminated carrier; however, the risk of continued transmission by reuse of wipes after 6 and 24 h was limited for all viruses. We conclude that cleaning wet spots with dry wipes efficiently reduced spot contamination on surfaces but that cross-contamination with noroviruses by wiping may result in an increased public health risk at high initial virus loads. For influenza virus, IPS wipes present an efficient one-step procedure for cleaning and disinfecting contaminated surfaces.

Tracing enteric viruses in the European berry fruit supply chain.

In recent years, numerous foodborne outbreaks due to consumption of berry fruit contaminated by human enteric viruses have been reported. This European multinational study investigated possible contamination routes by monitoring the entire food chain for a panel of human and animal enteric viruses. A total of 785 samples were collected throughout the food production chain of four European countries (Czech Republic, Finland, Poland and Serbia) during two growing seasons. Samples were taken during the production phase, the processing phase, and at point-of-sale. Samples included irrigation water, animal faeces, food handlers' hand swabs, swabs from toilets on farms, from conveyor belts at processing plants, and of raspberries or strawberries at points-of-sale; all were subjected to virus analysis. The samples were analysed by real-time (reverse transcription, RT)-PCR, primarily for human adenoviruses (hAdV) to demonstrate that a route of contamination existed from infected persons to the food supply chain. The analyses also included testing for the presence of selected human (norovirus, NoV GI, NoV GII and hepatitis A virus, HAV), animal (porcine adenovirus, pAdV and bovine polyomavirus, bPyV) and zoonotic (hepatitis E virus, HEV) viruses. At berry production, hAdV was found in 9.5%, 5.8% and 9.1% of samples of irrigation water, food handlers' hands and toilets, respectively. At the processing plants, hAdV was detected in one (2.0%) swab from a food handler's hand. At point-of-sale, the prevalence of hAdV in fresh raspberries, frozen raspberries and fresh strawberries, was 0.7%, 3.2% and 2.0%, respectively. Of the human pathogenic viruses, NoV GII was detected in two (3.6%) water samples at berry production, but no HAV was detected in any of the samples. HEV-contaminated frozen raspberries were found once (2.6%). Animal faecal contamination was evidenced by positive pAdV and bPyV assay results. At berry production, one water sample contained both viruses, and at point-of-sale 5.7% and 1.3% of fresh and frozen berries tested positive for pAdV. At berry production hAdV was found both in irrigation water and on food handler's hands, which indicated that these may be important vehicles by which human pathogenic viruses enter the berry fruit chain. Moreover, both zoonotic and animal enteric viruses could be detected on the end products. This study gives insight into viral sources and transmission routes and emphasizes the necessity for thorough compliance with good agricultural and hygienic practice at the farms to help protect the public from viral infections.

Virus transfer proportions between gloved fingertips, soft berries, and lettuce, and associated health risks.

Multiple outbreaks of human norovirus (hNoV) have been associated with fresh produce, such as soft berries and lettuce. Even though food handlers are considered an important source for the introduction of hNoV into food chains, their contribution to public health risks associated with hNoV remains unknown. To assess to which extent food handlers contribute to the introduction and spread of hNoV in fresh produce chains quantitative virus transfer data are needed. We estimated transfer proportions of hNoV GI.4, GII.4, murine norovirus (MNV-1), a culturable surrogate of hNoV, and human adenovirus (hAdV-2), a human pathogen proposed as an indicator for human faecal pollution, between gloved fingertips and raspberries, strawberries, and lettuce, by quantitative RT-PCR and cell culture if applicable. Virus transfer proportions were corrected for virus-matrix specific recoveries, and variability and uncertainty of the parameters were estimated. Virus transfer from gloves to soft berries was generally lower as compared to lettuce, with mean transfer proportions ranging between 0.1 to 2.3% and 9 to 10% for infectious MNV-1 and hAdV-2, respectively. Transfer from produce to glove was mostly greater than transfer from glove to produce, adding to the likelihood of virus transfer due to cross contamination from contaminated produce via food handlers. HNoV GI.4 and hNoV GII.4 showed no significant difference between their mean transfer proportions. Using the estimated transfer proportions, we studied the impact of low and high transfer proportions on the public health risk, based on a scenario in which a food handler picked raspberries with contaminated fingertips. Given the made assumptions, we could show that for a pathogen as infectious as hNoV, low transfer proportions may pose a greater public health risk than high transfer proportions, due to a greater viral spread. We demonstrated the potential of food handlers in spreading hNoV in food chains, showing that prevention of virus contamination on food handlers' hands is crucial for food safety. Nevertheless, complete prevention of virus contamination on fresh produce cannot be achieved in reality, and reliable and effective intervention measures are consequently required. We estimated that, especially for low transfer proportions, a robust one log10-unit reduction of infectious hNoV on contaminated produce, and on food handlers' hands, could lower the public health risk substantially. Using the obtained data in quantitative risk assessment will aid in elucidating the contribution of food handlers in hNoV transmission.

Aichi virus in sewage and surface water, the Netherlands.

Detection of Aichi virus in humans was initially reported in Japan in 1989. To establish a timeline for the prevalence of Aichi virus infection among humans in the Netherlands, we conducted molecular analysis of archival water samples from 1987-2000 and 2009-2012. Aichi virus RNA was detected in 100% (8/8) of sewage samples and 100% (7/7) of surface water samples collected during 1987-2000 and 100% (8/8) of sewage samples and 71% (5/7) of surface water samples collected during 2009-2012. Several genotype A and B Aichi virus lineages were observed over the 25-year period studied, but the time course of viral genetic diversity showed recent expansion of the genotype B population over genotype A. Our results show that Aichi virus has been circulating among the human population in the Netherlands since before its initial detection in humans was reported and that genotype B now predominates in this country.

A decision support tool to compare waterborne and foodborne infection and/or illness risks associated with climate change.

Climate change may impact waterborne and foodborne infectious disease, but to what extent is uncertain. Estimating climate-change-associated relative infection risks from exposure to viruses, bacteria, or parasites in water or food is critical for guiding adaptation measures. We present a computational tool for strategic decision making that describes the behavior of pathogens using location-specific input data under current and projected climate conditions. Pathogen-pathway combinations are available for exposure to norovirus, Campylobacter, Cryptosporidium, and noncholera Vibrio species via drinking water, bathing water, oysters, or chicken fillets. Infection risk outcomes generated by the tool under current climate conditions correspond with those published in the literature. The tool demonstrates that increasing temperatures lead to increasing risks for infection with Campylobacter from consuming raw/undercooked chicken fillet and for Vibrio from water exposure. Increasing frequencies of drought generally lead to an elevated infection risk of exposure to persistent pathogens such as norovirus and Cryptosporidium, but decreasing risk of exposure to rapidly inactivating pathogens, like Campylobacter. The opposite is the case with increasing annual precipitation; an upsurge of heavy rainfall events leads to more peaks in infection risks in all cases. The interdisciplinary tool presented here can be used to guide climate change adaptation strategies focused on infectious diseases.