Synergistic effects of sequential treatment using disinfectant and e-beam for inactivation of hepatitis a virus on fresh vegetables

Hepatitis A virus (HAV) has adversely affected public health worldwide, causing an economic burden on many countries. Fresh vegetables are reported as a source of HAV infections during production, harvesting, and distribution, which cause the emergence of foodborne illnesses. Therefore, in this study, the synergistic effects of chemical (sodium hypochlorite [NaOCl] and chlorine dioxide [ClO2]) and physical (electron-beam [e-beam] irradiation) sequential treatment for HAV inactivation on fresh vegetables were investigated, and the physicochemical quality changes of vegetables were evaluated after each treatment. On bell pepper and cucumber sequentially treated with NaOCl (50-500 ppm) and e-beam (1-5 kGy), the HAV titer was reduced by 0.19-4.69 and 0.28-4.78 log10 TCID50/mL, respectively. Sequential treatment with ClO2 (10-250 ppm) and e-beam (1-5 kGy) reduced the HAV titer on bell pepper and cucumber by 0.41-4.78 and 0.26-4.80 log10 TCID50/mL, respectively. The sequential treatments steadily decreased the HAV titers on each food by a significant difference (p < 0.05) compared to the controls. The treatment combinations of 500 ppm NaOCl and 3 kGy (e-beam) on bell pepper and 150 ppm NaOCl and 1 kGy (e-beam) on cucumber provided maximum synergistic effects. It was also found that sequential treatment with 50 ppm ClO2 and 5 kGy (e-beam) on bell pepper and 10 ppm ClO2 and 5 kGy (e-beam) on cucumber most efficiently inactivated HAV. Additionally, bell pepper and cucumber showed no significant quality changes (p < 0.05) after the treatment. Therefore, the sequential treatment with NaOCl or ClO2 and e-beam is expected to effectively control HAV on fresh vegetables without changing the food quality compared to either treatment alone.

Hepatitis a Vaccine as Opportunity of Primary Prevention for Food Handlers: A Narrative Review

The hepatitis A virus (HAV) is still a leading cause of viral hepatitis worldwide. After a long incubation period, the clinical manifestations range from asymptomatic infection to acute liver failure. The severity of the disease increases with age and pre-existing liver disease. The transmission is mainly via person-to-person contact or ingestion of contaminated food or water. Food contamination can occur at any step of the food chain, especially when infected people handle not-heated or otherwise-treated food. HAV is endemic in low-income countries because of poor sanitary and sociodemographic conditions. The populations of developed countries are highly susceptible, and large outbreaks occur when HAV is introduced from endemic countries due to globalization, travel, and movement of foodstuffs. HAV prevention includes hygiene practices, immunoglobulins, and vaccination. Safe and effective inactivated and live attenuated vaccines are available and provide long-term protection. The vaccine targets are children and subjects at increased risk of HAV exposure or serious clinical outcomes. This review discusses the critical role of food handlers in the spread of HAV and the opportunity for food industry employers to consider food handler immunization a tool to manage both food safety in compliance with HACCP principles and food operators' biologic risk.

Hepatitis A in the Eastern Mediterranean Region: a comprehensive review

INTRODUCTION

With 583 million inhabitants, the Eastern Mediterranean Region (EMR) is a worldwide hub for travel, migration, and food trade. However, there is a scarcity of data on the epidemiology of the hepatitis A virus (HAV).

METHODS

The MEDLINE and grey literature were systematically searched for HAV epidemiological data relevant to the EMR region published between 1980 and 2020 in English, French, or Arabic.

RESULTS

Overall, 123 publications were extracted. The proportion of HAV cases among acute viral hepatitis cases was high. HAV seroprevalence rate ranged from 5.7% to 100.0% and it was decreasing over time while the average age at infection increased.

CONCLUSION

In the EMR, HAV remains a significant cause of acute viral hepatitis. The observed endemicity shift will likely increase disease burden as the population ages. Vaccinating children and adopting sanitary measures are still essential to disease prevention; vaccinating at-risk groups might reduce disease burden even further.

Efficient capturing and sensitive detection of hepatitis A virus from solid foods (green onion, strawberry, and mussel) using protamine-coated iron oxide (Fe3O4) magnetic nanoparticles and real-time RT-PCR

Hepatitis A virus (HAV) continues to be a public health concern and has caused large foodborne outbreaks and economic losses worldwide. Rapid detection of HAV in foods can help to confirm the source of outbreaks in a timely manner and prevent more people getting infected. In order to efficiently detect HAV at low levels of contamination in foods, rapid and easy-to-use techniques are required to separate and concentrate viral particles to a small volume. In the current study, HAV particles were eluted from green onion, strawberry, and mussel using glycine buffer (0.05 M glycine, 0.14 M NaCl, 0.2% (v/v) Tween 20, pH 9.0) and suspended viral particles were captured using protamine-coated magnetic nanoparticles (PMNPs). This process caused a selective concentration of the viral particles, which could be followed by quantitative real-time RT-PCR analysis. Results showed that pH, NaCl concentration, and PMNP amount used for the capturing had significant effects on the recovery efficiency of HAV (P < 0.05). The highest recovery rate was obtained at pH 9.0, 0.14 M NaCl, and 50 μL of PMNPs. The optimized PMNP capturing method enabled the rapid capture and concentration of HAV. A sensitive real-time RT-PCR test was developed with detection limits of 8.3 × 10⁰ PFU/15 g, 8.3 × 10¹ PFU/50 g, and 8.3 × 10⁰ PFU/5 g of HAV in green onion, strawberry, and mussel, respectively. In conclusion, the PMNP method is rapid and convenient in capturing HAV from complex solid food samples and can generate concentrated HAV sample solutions suitable for high-sensitivity real time RT-PCR detection of the virus.

Monitoring of new coronavirus (SARS-CoV-2): Origin, transmission, and food preservation methods

Unfortunately, there is limited research on coronavirus survival of food products and also food processing. The knowledge of the physical and chemical characteristics of coronaviruses mostly comes from the study of SARS-CoV and MERS-CoV physical (i.e., thermal processing, chilling and freezing, microwave irradiation, ultraviolet light, gamma irradiation, high hydrostatic pressure) and chemical (acidification and use of common disinfectants in the food industry like chlorinated derivatives and ozone) are means which could be used to inactive the coronaviruses or reduce the infection. These methods can be applied individually or in combination to act better performance. Thermal processing is one of the most effective methods for inactive coronavirus. Heating at 75°C (15-60 min) and 65°C (1 min) was the best temperature for inactive SARS-CoV and MERS virus, respectively. Among irradiation methods (microwave, UV, and gamma), the most effective one is UVC rays. Moreover, the use of disinfectant like chlorinated derivatives is appropriate way to disinfect food product surfaces.

Novelty impact statement

This review provided updated information on effective strategies for inactive coronavirus that can be used in the food industry. SARS-CoV-2 as a new pandemic coronavirus was initiated from contaminated foods and can be transmitted by close contact, aerosols, and food surfaces. Food preservation (physical and chemical) methods could decrease SARS-CoV-2. Probably, heating and UVC are the most effective approach to inactive SARS-CoV-2. Despite the findings of coronavirus inactivation which were here discussed, much research is still needed for the development of new approaches to overcome the coronavirus.

Incidence of hepatitis A and hepatitis E viruses and norovirus and rotavirus in fish and shrimp samples caught from the Persian Gulf

ABSTRACT Foodborne viruses including hepatitis A virus (HAV), norovirus (NoV), rotavirus (RoV) and hepatitis E virus (HEV) are easily transmitted through contaminated seafoods. The current research was done to assess the incidence of RoV, NoV GI and GII,hAV and hEV in fish and shrimp samples caught from the Persian Gulf, Iran. Three-hundred and twenty fish and shrimp samples were collected. The presence of foodborne viruses were assessed by the real-time PCR. Forty-nine out of 320 (15.31%) fish and shrimp samples were positive for foodborne viruses. Distribution of hAV, NoV GI and NoV GII amongst all studied samples were 0.93%, 5.93% and 8.43%, respectively. hEV and RoV viruses were not found in studied samples. Parastromateus niger and Scomberomorus commerson fish and Penaeus monodon shrimp were the most frequently contaminated samples. Simultaneous incidence of hAV and NoV GI and hAV and NoV GII were 0.31% and 0.93%, respectively. Distribution of foodborne viruses in samples collected through spring, summer, autumn and winter seasons were 14.28%, 9.33%, 11.76% and 24.44%, respectively. Findings revealed that the incidence of foodborne viruses was significantly associated with seafood species and also season of sampling.

Inactivation of Foodborne Viruses by High-Pressure Processing (HPP)

High-pressure processing (HPP) is an innovative non-thermal food preservation method. HPP can inactivate microorganisms, including viruses, with minimal influence on the physicochemical and sensory properties of foods. The most significant foodborne viruses are human norovirus (HuNoV), hepatitis A virus (HAV), human rotavirus (HRV), hepatitis E virus (HEV), human astrovirus (HAstV), human adenovirus (HuAdV), Aichi virus (AiV), sapovirus (SaV), and enterovirus (EV), which have also been implicated in foodborne outbreaks in various countries. The HPP inactivation of foodborne viruses in foods depends on high-pressure processing parameters (pressure, temperature, and duration time) or non-processing parameters such as virus type, food matrix, water activity (aw), and the pH of foods. HPP was found to be effective for the inactivation of foodborne viruses such as HuNoV, HAV, HAstV, and HuAdV in foods. HPP treatments have been found to be effective at eliminating foodborne viruses in high-risk foods such as shellfish and vegetables. The present work reviews the published data on the effect of HPP processing on foodborne viruses in laboratory media and foods.

Water and Pathogenic Viruses Inactivation—Food Engineering Perspectives

Water is an essential component of food structures and biological materials. The importance of water as a parameter affecting virion stability and inactivation has been recognized across disciplinary areas. The large number of virus species, differences in spreading, likelihood of foodborne infections, unknown infective doses, and difficulties of infective virus quantification are often limiting experimental approaches to establish accurate data required for detailed understanding of virions’ stability and inactivation kinetics in various foods. Furthermore, non-foodborne viruses, as shown by the SARS-CoV-2 (Covid-19) pandemic, may spread within the food chain. Traditional food engineering benefits from kinetic data on effects of relative humidity (RH) and temperature on virion inactivation. The stability of enteric viruses, human norovirus (HuNoV), and hepatitis A (HAV) virions in food materials and their resistance against inactivation in traditional food processing and preservation is well recognized. It appears that temperature-dependence of virus inactivation is less affected by virus strains than differences in temperature and RH sensitivity of individual virus species. Pathogenic viruses are stable at low temperatures typical of food storage conditions. A significant change in activation energy above typical protein denaturation temperatures suggests a rapid inactivation of virions. Furthermore, virus inactivation mechanisms seem to vary according to temperature. Although little is known on the effects of water on virions’ resistance during food processing and storage, dehydration, low RH conditions, and freezing stabilize virions. Enveloped virions tend to have a high stability at low RH, but low temperature and high RH may also stabilize such virions on metal and other surfaces for several days. Food engineering has contributed to significant developments in stabilization of nutrients, flavors, and sensitive components in food materials which provides a knowledge base for development of technologies to inactivate virions in foods and environment. Novel food processing, particularly high pressure processing (HPP) and cold plasma technologies, seem to provide efficient means for virion inactivation and food quality retention prior to packaging or food preservation by traditional technologies.

Microbial Contamination of Fresh Produce: What, Where, and How?

Promotion of healthier lifestyles has led to an increase in consumption of fresh produce. Such foodstuffs may expose consumers to increased risk of foodborne disease, as often they are not subjected to processing steps to ensure effective removal or inactivation of pathogenic microorganisms before consumption. Consequently, reports of ready-to-eat fruit and vegetable related disease outbreak occurrences have increased substantially in recent years, and information regarding these events is often not readily available. Identifying the nature and source of microbial contamination of these foodstuffs is critical for developing appropriate mitigation measures to be implemented by food producers. This review aimed to identify the foodstuffs most susceptible to microbial contamination and the microorganisms responsible for disease outbreaks from information available in peer-reviewed scientific publications. A total of 571 outbreaks were identified from 1980 to 2016, accounting for 72,855 infections and 173 deaths. Contaminated leafy green vegetables were responsible for 51.7% of reported outbreaks. Contaminated soft fruits caused 27.8% of infections. Pathogenic strains of Escherichia coli and Salmonella, norovirus, and hepatitis A accounted for the majority of cases. Large outbreaks resulted in particular biases such as the observation that contaminated sprouted plants caused 31.8% of deaths. Where known, contamination mainly occurred via contaminated seeds, water, and contaminated food handlers. There is a critical need for standardized datasets regarding all aspects of disease outbreaks, including how foodstuffs are contaminated with pathogenic microorganisms. Providing food business operators with this knowledge will allow them to implement better strategies to improve safety and quality of fresh produce.

Causes and countermeasures for repeated outbreaks of hepatitis A among adults in Korea

The 2019 hepatitis A outbreak has become increasingly prevalent among adults in Korea and is the largest outbreak since that in 2009-2010. The incidence in the current outbreak is highest among adults aged 35-44 years, corresponding to the peak incidence among those aged 25-34 years 10 years ago. This may indicate a cohort effect in the corresponding age group. Causes of these repeated outbreaks of hepatitis A in Korea are low level of immunity among adults, Korean food culture that consumes raw seafood such as salted clam and inadequate public health system. Among countermeasures, along with general infectious disease control measures including control of the infectious agent, infection spread, and host, urgent actions are needed to review the vaccination policy and establish an adequate public health system.

Antiviral Activity of Essential Oils Against Hepatitis A Virus in Soft Fruits

Berries have repeatedly been associated with outbreaks of hepatitis A virus (HAV) infection. The fruits are usually minimally processed in the food industry due to their delicate nature. While washing treatments partially remove enteric viruses, the commonly used chemical additives produce toxic by-products. A valid alternative to preserve the food safety of these products could be the use of essential oils (EOs). EOs exert antimicrobial activity and do not interfere with the nutritional characteristics of food products. We investigated the efficacy of four essential oils, lemon (Citrus limon), sweet orange (Citrus sinensis), grapefruit (Citrus paradisi), and rosemary cineole (Rosmarinus officinalis chemotype 1.8 cineole) in reducing viral loads of HAV in soft fruits. Mixed fruit berries were inoculated with 10^6.74 TCID₅₀/ml of HAV, and treated with four different EOs (0.5% lemon, 0.1% sweet orange and grapefruit, and 0.05% rosemary) for 1 h at room temperature. Virus infectivity was then assessed by titration assays for its ability to grow on cell cultures. A statistically significant reduction in HAV titer on the fruit surface was observed after treating the berries with EOs of lemon (2.84 log TCID₅₀/ml), grapefruit (2.89 log TCID₅₀/ml), and rosemary cineole (2.94 log TCID₅₀/ml). Rosemary cineole was the most effective EO in reducing viral titer on berries, followed by grapefruit EO. These results improve our knowledge about the antiviral activity of these EOs and highlight their potential use in fresh produce sanitation.

Key characteristics of foods with an elevated risk for viral enteropathogen contamination

Viral enteropathogens are one of the leading causative agents of foodborne illnesses in both the United States and the European Union. While human noroviruses and hepatitis A virus cause the vast majority of outbreaks and illnesses, there are handful of human enteric viruses that contribute to sporadic outbreaks worldwide including astrovirus, sapovirus, rotavirus, enterovirus and Aichi virus. In addition, hepatitis E virus is increasingly being recognized as an emerging zoonotic threat within the food supply. This review aims to briefly describe the primary human enteric viruses of concern with respect to foodborne transmission. Next, we focus on the contamination and persistence of these viruses within three high-risk food commodities-leafy greens, soft red fruits and bivalve mollusks. As opposed to detailing the specific routes by which these foods can be contaminated with enteric viruses, we have chosen to focus on their persistence and specific interactions within the food itself. Therefore, the processes of attachment and internalization of the viruses in foods have been emphasized. Looking forward, the implications of these specific interactions of human enteric viruses with leafy greens, soft red fruits and bivalve mollusks are briefly considered within the context of future prevention and control strategies.

Improving efficiency of viability-qPCR for selective detection of infectious HAV in food and water samples

AIM

To improve the efficacy of intercalating dyes to distinguishing between infectious and inactivated hepatitis A virus (HAV) in food.

METHODS AND RESULTS

Different intercalating dyes were evaluated for the discrimination between infectious and thermally inactivated HAV suspensions combining with the RT-qPCR proposed in the ISO 15216. Among them, PMAxx was the best dye in removing the RT-qPCR signal from inactivated HAV. Applied to lettuce and spinach, PMAxx-Triton pretreatment resulted in complete removal of the RT-qPCR signal from inactivated HAV. Likewise, this study demonstrates that this pretreatment is suitable for the discrimination of inactivated HAV in shellfish without further sample dilution. In mussels and oysters, the developed viability RT-qPCR method reduced the signal of inactivated HAV between 1·7 and 2·2 logs at high inoculation level, and signal was completely removed at low inoculation level.

CONCLUSIONS

This study showed that the use of PMAxx is an important improvement to assess HAV infectivity by RT-qPCR. It was shown that PMAxx-Triton pretreatment is suitable for the analysis of infectious HAV in complex food samples such as vegetables and shellfish.

SIGNIFICANCE AND IMPACT OF THE STUDY

The PMAxx-Triton pretreatment can be easily incorporated to the ISO norm for infectious virus detection.

Shellfish: Nutritive Value, Health Benefits, and Consumer Safety

Shellfish is a major component of global seafood production. Specific items include shrimp, lobsters, oysters, mussels, scallops, clams, crabs, krill, crayfish, squid, cuttlefish, snails, abalone, and others. Shellfish, in general, contain appreciable quantities of digestible proteins, essential amino acids, bioactive peptides, long-chain polyunsaturated fatty acids, astaxanthin and other carotenoids, vitamin B₁₂ and other vitamins, minerals, including copper, zinc, inorganic phosphate, sodium, potassium, selenium, iodine, and also other nutrients, which offer a variety of health benefits to the consumer. Although shellfish are generally safe for consumption, their exposure to diverse habitats, the filter feeding nature of shellfish such as oysters, clams, and mussels, and unhealthy farming and handling practices may occasionally entail health risks because of possible presence of various hazards. These hazards include pathogenic organisms, parasites, biotoxins, industrial and environmental pollutants, heavy metals, process-related additives such as antibiotics and bisulfite, and also presence of allergy-causing compounds in their bodies. Most of the hazards can be addressed by appropriate preventive measures at various stages of harvesting, farming, processing, storage, distribution, and consumption. Furthermore, consumer safety of shellfish and other seafood items is strictly monitored by international, governmental, and local public health organizations. This article highlights the nutritional value and health benefits of shellfish items and points out the various control measures to safeguard consumer safety with respect to the products.

Effect of green tea extract on enteric viruses and its application as natural sanitizer

In this work, the effect of green tea extract (GTE) was assessed against murine norovirus (MNV) and hepatitis A virus (HAV) at different temperatures, exposure times and pH conditions. Initially, GTE at 0.5 and 5 mg/ml were individually mixed with each virus at 5 log TCID50/ml and incubated 2 h at 37 °C at different pHs (from 5.5 to 8.5). GTE affected both viruses depending on pH with higher reductions observed in alkaline conditions. Secondly, different concentrations of GTE (0.5 and 5 mg/ml) were mixed with viral suspensions and incubated for 2 or 16 h at 4, 25 and 37 °C at pH 7.2. A concentration-, temperature- and exposure time-dependent response was showed by GTE in suspension tests, where complete inactivation was achieved after overnight exposure at 37 °C for both viruses and also at 25 °C for HAV. In addition, antiviral effect of GTE proved efficient in the surface disinfection tests since 1.5 log reduction and complete inactivation were recorded for MNV and HAV on stainless steel and glass surfaces treated with 10 mg/ml GTE for 30 min, analyzed in accordance with ISO 13697:2001. GTE was also evaluated as a natural disinfectant of produce, showing 10 mg/ml GTE reduced MNV and HAV titers in lettuce and spinach by more than 1.5 log after 30 min treatment. The results show a potential of GTE as natural disinfectant able to limit enteric viral (cross-)contaminations conveyed by food and food-contact surfaces.

Ethnopharmacological Approaches for Therapy of Jaundice: Part I

Jaundice is a very common symptom especially in the developing countries. It is associated with several hepatic diseases which are still major causes of death. There are many different approaches to jaundice treatment and the growing number of ethnomedicinal studies shows the plant pharmacology as very promising direction. Many medicinal plants are used for the treatment of jaundice, however a comprehensive review on this subject has not been published. The use of medicinal plants in drug discovery is highly emphasized (based on their traditional and safe uses in different folk medicine systems from ancient times). Many sophisticated analytical techniques are emerging in the pharmaceutical field to validate and discover new biologically active chemical entities derived from plants. Here, we aim to classify and categorize medicinal plants relevant for the treatment of jaundice according to their origin, geographical location, and usage. Our search included various databases like Pubmed, ScienceDirect, Google Scholar. Keywords and phrases used for these searches included: "jaundice," "hyperbilirubinemia," "serum glutamate," "bilirubin," "Ayurveda." The first part of the review focuses on the variety of medicinal plant used for the treatment of jaundice (a total of 207 medicinal plants). In the second part, possible mechanisms of action of biologically active secondary metabolites of plants from five families for jaundice treatment are discussed.

Ethnopharmacological Approaches for Therapy of Jaundice: Part I

Jaundice is a very common symptom especially in the developing countries. It is associated with several hepatic diseases which are still major causes of death. There are many different approaches to jaundice treatment and the growing number of ethnomedicinal studies shows the plant pharmacology as very promising direction. Many medicinal plants are used for the treatment of jaundice, however a comprehensive review on this subject has not been published. The use of medicinal plants in drug discovery is highly emphasized (based on their traditional and safe uses in different folk medicine systems from ancient times). Many sophisticated analytical techniques are emerging in the pharmaceutical field to validate and discover new biologically active chemical entities derived from plants. Here, we aim to classify and categorize medicinal plants relevant for the treatment of jaundice according to their origin, geographical location, and usage. Our search included various databases like Pubmed, ScienceDirect, Google Scholar. Keywords and phrases used for these searches included: “jaundice,” “hyperbilirubinemia,” “serum glutamate,” “bilirubin,” “Ayurveda.” The first part of the review focuses on the variety of medicinal plant used for the treatment of jaundice (a total of 207 medicinal plants). In the second part, possible mechanisms of action of biologically active secondary metabolites of plants from five families for jaundice treatment are discussed.

Pathogens of Food Animals: Sources, Characteristics, Human Risk, and Methods of Detection

Pathogens associated with food production (livestock) animals come in many forms causing a multitude of disease for humans. For the purpose of this review, these infectious agents can be divided into three broad categories: those that are associated with bacterial disease, those that are associated with viruses, and those that are parasitic in nature. The goal of this chapter is to provide the reader with an overview of the most common pathogens that cause disease in humans through exposure via the food chain and the consequence of this exposure as well as risk and detection methods. We have also included a collection of unusual pathogens that although rare have still caused disease, and their recognition is warranted in light of emerging and reemerging diseases. These provide the reader an understanding of where the next big outbreak could occur. The influence of the global economy, the movement of people, and food makes understanding production animal-associated disease paramount to being able to address new diseases as they arise.

Efficacy of domestic cooking inactivation of human hepatitis A virus in experimentally infected manila clams (Ruditapes philippinarum)

AIM

The aim of this work was to evaluate the efficacy of domestic cooking in inactivating Manila clams experimentally infected with human hepatitis A virus (HAV).

METHODS AND RESULTS

Electronic temperature probes were positioned to measure the internal temperature of Manila clams during domestic cooking. Two batches were infected with 10(7) and 10(5) TCID50  ml(-1) of HAV. The infected whole-in-shell clams were divided into three replicates and cooked on a conventional stove both singularly and in group and removed from the pan at fixed intervals. Pools of three digestive glands were examined by virus isolation for three blind passages and cell culture supernatant tested with real-time PCR.

CONCLUSION

Results showed that 2-min cooking by a traditional domestic method at a temperature close to 100°C, after the opening up of the valves of all the clams, can completely devitalize the HAV in high viral load-infected clams.

SIGNIFICANCE AND IMPACT OF THE STUDY

This is the first study on inactivation of HAV in experimentally infected Manila clams subjected to domestic cooking. At present, labelling all lagoon products as 'requiring cooking before consumption' is highly recommended, but no specifications are given on how long and at what temperature they should be cooked. Considering the high commercial value of Manila clams, our results can provide both the producers and the consumer with useful indications on how to cook clams to prevent the risk of HAV foodborne illness.