Exploring the potential of foodborne transmission of respiratory viruses

Predicting and preventing the next viral disease transmitted through food

The ability of viruses to infect humans following oral exposure and disrupt normal physiological or anatomical functions is a hallmark of their potential to cause foodborne disease. While the etiology of the vast majority of foodborne diseases remains undetermined, viruses are often identified as the culprit when the cause is ascertained. Many undiagnosed causes of foodborne illnesses, especially sporadic cases, may go undetected or be caused by yet-to-be-identified viruses. The potential for food to become a transmission vehicle for viral diseases that are not typically acquired following ingestion may be described within the epidemiological paradigm. This model considers the characteristics and interactions of the host (the human), the agent (the virus), and the environment (the food, the food producing animal or the food production environment). Importantly, these factors are not static and evolution of viruses, transformations in agrifood systems, and changes in environmental conditions and human health and behaviour may contribute to increased pathogenicity, virulence, or exposure. In the context of determining the potential for additional viruses to emerge as important causes of foodborne disease, factors that contribute to hazard characterization (e.g., receptor affinity and distribution) and exposure assessment (e.g., prevalence in food animals and food hygiene) are reviewed. Although it is not possible to predict the type, the timing nor the location of the emergence of the next important cause of foodborne viral disease, the deployment and implementation of actions and behaviours related to personal and food hygiene, sanitation, and safe food handling practices can reduce the likelihood and impact of known and emergent viruses on the safety of the food supply and human health.

Viral Transmission in Sea Food Systems: Strategies for Control and Emerging Challenges

The SARS-CoV-2 pandemic had widespread and severe impacts on both the global economy and human health. Facing the continuously mutating virus, this crisis has heightened concerns among consumers and businesses regarding viral transmission through seafood, particularly in the face of emerging, unknown viruses, underscoring our preparedness gaps. This review provides a succinct overview of the survival mechanisms of prevalent viruses in seafood, examines potential transmission pathways to humans during seafood processing, and discusses strategies for mitigating their spread throughout the seafood supply chain. Furthermore, the discussion highlights emerging trends in innovative antiviral technologies aimed at enhancing food safety. Person-to-person transmission remains the most likely source of infection within the supply chain. Therefore, it is still imperative to adhere to the implementation of standard processes, namely good manufacturing practices (GMP) and good hygiene practices (GHP), in the seafood business. In light of the significant losses caused by this crisis and the persistent presence of various viruses within the seafood supply chain, efforts are needed to implement predictive and preventive measures against potential emerging viruses. Future research should focus on monitoring and limiting viral transmission by integrating Industry 4.0 applications, smart technologies, and antiviral packaging, maximizing the potential of these emerging solutions.

Decoding the SARS-CoV-2 infection process: Insights into origin, spread, and therapeutic approaches

Globally, over 768 million confirmed cases and 6.9 million deaths had been documented as of July 17, 2023. Coronaviruses have a relatively large RNA genome. As with other viruses, SARS-CoV-2 does have an envelope film produced from host cells that are assisted by virally encoded glycoproteins that are required for infectivity, immunological assault, and viral particle production. Although the intermediate source of origin and transmission to humans is unexplained, rapid transmission from human to human has been established. This review focuses on the mechanistic framework for understanding the SARS-CoV-2 viral infection. Additionally, it discusses the origins and implications of COVID-19 using direct quotations from the published scientific literature to avoid misinterpretation of this catastrophic event that resulted in a massive loss of human life and impact on the global economy. The current available information unfolds large number of topics related with COVID-19 and/or the coronavirus (SARS-CoV-2) responsible of the disease. This review article also delves into the multifaceted aspects of COVID-19 and SARS-CoV-2, with a specific focus on a controversial yet essential issue: the possible association between SARS-CoV-2's origin and aldose reductase, an enzyme known for its role in diabetic retinopathy. Exploring this connection holds utmost significance, offering valuable insights into COVID-19's pathogenesis and unlocking new avenues for therapeutic interventions. It is important to trace back the evolution of coronaviruses and reveal the possible origin of the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), which causes the coronavirus disease 2019 (COVID-19).

Hot topic: Avian influenza subtype H5N1 in US dairy-A preliminary dairy foods perspective

In February and March of 2024, an unusual illness began affecting dairy herds primarily in Texas and neighboring states. The causative agent of this illness was ultimately confirmed in late March 2024 to be a strain of highly pathogenic avian influenza H5N1 belonging to clade 2.3.4.4b. In the months following the emergence of this viral disease in cattle, infections have spread to at least 191 herds in 13 states at the time of this writing in August 2024, primarily through cattle and human movement. Surprisingly, early examination of raw milk samples from clinically affected animals indicated that the virus had an affinity for the mammary tissue, and viral shedding into raw milk occurred at high levels, exceeding 108 log10 50% tissue culture infectious dose (TCID50) in some cases. These high viral loads coupled with evidence that farm cats who consumed raw milk from clinically ill animals were infected and exhibited high mortality rates, raised concerns about the safety of the US milk supply for human consumption. To date, 4 cow-associated human infections have been reported, all from farm employees with direct contact with infected animals. Several parameters ultimately affect the theoretical public health risk from consumption of dairy products manufactured from a milk supply containing H5N1, namely (1) initial viral load, (2) persistence of H5N1 in raw milk, (3) viral inactivation through processing practices including pasteurization, and (4) human susceptibility and infectious dose. In the short period since the emergence of this disease in dairy cattle in the United States, research has begun to answer these critical questions, although our knowledge is still quite limited at this time. Here we review the literature available from the current H5N1 outbreak in US dairy cattle, as well as selected relevant literature from previous research in other animal agriculture sectors, that affect our current understanding of the parameters associated with the food safety risk of this disease in the US dairy supply chain.

In vitro digestion of SARS-CoV-2 contaminated berries reveals high inactivation of infectious virus during gastrointestinal passage

IMPORTANCE

During the pandemic, news outlets occasionally reported on the detection of severe acute respiratory syndrome coronavirus-2 (SARS-CoV-2) RNA on various foods, raising concerns over contaminated foods initiating infections. Coronavirus disease 2019 (COVID-19) patients often experience gastrointestinal symptoms and shed SARS-CoV-2 RNA in their feces. In addition, active virus replication in the gastrointestinal tract was shown; however, infectious viruses were rarely detected in feces. We previously showed that SARS-CoV-2 remained infectious on frozen berries for at least a month. Here, in vitro digestion models showed that SARS-CoV-2 on berries exhibits minimal inactivation at the oral phase and the virus may escape gastric inactivation early during feeding. However, high intestinal inactivation of the virus on berries suggested that SARS-CoV-2 was less likely to initiate infection in the small intestine. In contrast, the oral cavity is a potential site where infection might be initiated, providing more input for the gastrointestinal tract. High intestinal inactivation might explain the difficulty of detecting infectious SARS-CoV-2 in feces but not of virus RNA.

Human Mastadenovirus Infections in Children: A Review of the Current Status in the Arab World in the Middle East and North Africa

Human mastadenovirus (HAdV) is a non-enveloped icosahedral virus with double-stranded DNA genomes. The mortality rate of HAdV infections can reach 35.5%, while gastroenteritis HAdV infections, HAdV pneumonia, and disseminated disease tend to show a worse outcome, with rates ranging from 44.2% to 50%. In addition, HAdV can cause infections at any age but most commonly in the pediatric population, especially in young children and infants. Therefore, this review aims to assess the current status of HAdV infections among children in the Arab World, particularly in the Middle East and North Africa. Web of Science, Scopus, PubMed, EMBASE, and Google Scholar databases for publications in English were searched up to July 2022 for relevant articles. The literature search yielded a total of 21 studies, which were included in this review. Studies reporting HAdV infections in children were conducted in 17 out of the 22 countries. The average prevalence rate of HAdV infections in children was 12.7%, with average prevalence rates of 12.82% and 12.58% in the Middle East and North African countries, respectively. The highest prevalence rate (28.3%) was reported in Egypt, whereas the lowest prevalence (1.5%) was reported in Sudan. The included studies presented children with signs and symptoms of gastroenteritis, acute respiratory infection, acute diarrhea, and acute hemorrhagic conjunctivitis. In conclusion, the average prevalence rate of HAdV infections in children was 12.7%, with average prevalence rates of 12.82% and 12.58% in the Middle East and North African countries, respectively. Finding the precise prevalence rate of this virus is crucial because it will guide future planning for effective disease control and the selection of particular treatment options during epidemics and special seasons.

Efficacy of washing produce in removing human coronavirus OC43 and murine norovirus

AIMS

Fresh produce is often a vehicle for the transmission of foodborne pathogens such as human norovirus. Thus, it is recommended to wash the surface of produce before consumption, and one of the most common ways to wash produce is by rinsing under running tap water. This study determined the effectiveness of removal of human coronavirus-OC43 (HCoV-OC43), as a surrogate for severe acute respiratory syndrome coronavirus-2 (SARS-CoV-2) and murine norovirus-1 (MNV-1), as a surrogate for human norovirus, from contaminated lettuce, apples and cucumbers.

METHODS AND RESULTS

The produce surfaces were artificially inoculated in conjunction with faecal material to represent natural contamination. Rinsing under tap water for 10 s at 40 ml/s removed 1.94 ± 0.44, 1.42 ± 0.00 and 1.42 ± 0.42 log of HCoV-OC43 from apple, cucumber and lettuce respectively. The same washing technique removed 1.77 ± 0.17, 1.42 ± 0.07 and 1.79 ± 0.14 log of MNV-1 from apple, cucumber and lettuce respectively. This washing technique was effective at reducing a significant amount of viral contamination, however, it was not enough to eliminate the entire contamination. There was no significant difference in the reduction of viral load between the two viruses, nor between the three surfaces tested in this study.

CONCLUSIONS

Our data suggest that washing under tap water would be an efficient way of reducing the risk of foodborne viral transmission only if the level of contamination is less than 2 log PFU.

SIGNIFICANCE AND IMPACT OF STUDY

This study demonstrates that running tap water was effective at reducing the amount of infectious HCoV-OC43 and MNV on produce surfaces, and washing produce continues to be an important task to perform prior to consumption to avoid infection by foodborne viruses, particularly for foods which are eaten raw.

Transmission of SARS-CoV-2 on Cold-Chain Food: Precautions Can Effectively Reduce the Risk

The COVID-19 pandemic has generated a new era in the world, also in the food safety. Up to now, there is no evidence to suggest that people can infect COVID-19 via food contaminated by SARS-CoV-2. Here, we analyzed the results of regular SARS-CoV-2 nucleic acid testing of considerable cold-chain food practitioners, cold-chain food surfaces, and their internal or external packaging as well as their associated environments, aiming to explore the risk of cold-chain food being contaminated by SARS-CoV-2 and the probability of people infecting COVID-19 through contaminated cold-chain food in the context of COVID-19 epidemic. This study found that only two batches of cold-chain food were contaminated by SARS-CoV-2, none of the cold-chain food handler were infected due to effective regulatory measures for cold-chain food. Therefore, effective supervision and preventive methods could effectively reduce the transmission risk of SARS-CoV-2 on cold-chain food.

Antimicrobial Nonwoven Fabrics Incorporated with Levulinic Acid and Sodium Dodecyl Sulfate for Use in the Food Industry

Safe and cost-effective antimicrobial fabrics (e.g., face masks and air filters) are conducive to preventing the spread and transmission of respiratory microorganisms in food processing plants and retail establishments. The objective of this study was to coat fabrics with two commonly used compounds in the food industry: levulinic acid (LVA) and sodium dodecyl sulfate (SDS) and determine the antimicrobial efficacy of the coated fabrics against bacterial solutions, aerosols, and influenza A virus subtype H1N1. In addition, air permeability and shelf-life of the LVA/SDS coated fabrics were also examined. Nonwoven fabrics were dip-coated with three concentrations (w/v, 0.5% LVA + 0.1% SDS, 1% LVA + 0.5% SDS, and 2% LVA + 1% SDS) of LVA and SDS and challenged with bacterial solutions (Staphylococcus aureus and Escherichia coli, ca. 7.0 log CFU/coupon) for a contact time of 3, 5, and 10 min. The coated fabrics were also challenged with S. aureus aerosol and H1N1 virus following standard operations of ASTM F2101-19 and ISO 18184:2019, respectively. The 1% LVA + 0.5% SDS coated fabrics showed potent antibacterial efficacy against both bacterial solutions (>6.0-log reduction to under the detection limit of 1.0 log CFU/coupon for S. aureus; ca. 1.0-log reduction for E. coli) and aerosols (>3.6-log reduction to under the detection limit), with greater inactivation occurring at higher concentrations and longer exposure time. Moreover, the coated fabrics inactivated >99% of the H1N1 virus. The shelf-life of the coated fabrics was stable within 12 months and the air permeability was not adversely affected with the coating concentrations less than 1% LVA + 0.5% SDS. Results reveal these low-cost and safe materials have the potential to be used to coat fabrics in the food industry to combat the spread and transmission of pathogens.

Protective Effect of Food Against Inactivation of Human Coronavirus OC43 by Gastrointestinal Fluids

The involvement of the gastrointestinal (GI) tract in severe acute respiratory syndrome coronavirus-2 (SARS-CoV-2) infection has been reported in multiple studies. Since it has been demonstrated that human intestinal epithelial cells support productive viral replication and that a substantial portion of infected individuals shed the virus in feces, the possibility of fecal-oral and fecal-respiratory modes of transmission have been proposed for SARS-CoV-2. In order to establish viral replication in the intestine, enteric viruses need to retain their infectivity in often low pH gastric fluids, and in intestinal fluids, which contain digestive enzymes and bile salts. In this study, we examined whether human coronaviruses OC43 (HCoV-OC43) can remain infectious in simulated GI fluids that models human fasting-state and fed-state, in the presence or absence of food. We demonstrated that except for fasting-state gastric fluid (pH 1.6), the virus can remain infectious in all other gastrointestinal fluids for 1 h. Furthermore, we demonstrated that presence of food could significantly improve viral survival in gastric fluids. Therefore, this study provides evidence that ingestion with food could protect the virus against inactivation by the GI fluids.

SARS-CoV-2 remains infectious for at least a month on artificially-contaminated frozen berries

The potential transmission of SARS-CoV-2 via food has been controversial since the beginning of the COVID-19 pandemic. To investigate these concerns, reliable detection methods and data on virus die-off rates in various foods are needed. Here, an FDA-standard method for the detection of enteric viruses’ RNA from soft fruits was modified for the recovery of infectious SARS-CoV-2. Then, the survival of SARS-CoV-2 on berries was investigated as well as the effectiveness of washing virus-contaminated berries with water. The modified method did not significantly reduced log infectivity titers of recovered viruses, but berries did. The detection limit of the method for infectious SARS-CoV-2 was ∼2.97 log TCID50/g of berries. On SARS-CoV-2-inoculated berries that were stored at 4 °C for 7 days, significant reductions in SARS-CoV-2 infectivity were observed over time. In contrast, on frozen berries, infectious SARS-CoV-2 was recovered for 28 days without significant reductions. Washing SARS-CoV-2-inoculated berries with water removed >90% of infectious viruses within 10 min; however, infectious viruses were detected in wash water. Therefore, on fresh berries infectious viruses are markedly inactivated over time and can be largely removed by washing with water. However, the prolonged survival of SARS-CoV-2 on frozen berries suggests that the virus can potentially spread through frozen fruits.

Respiratory viruses in foods and their potential transmission through the diet: A review of the literature

Respiratory viruses are the main agents causing respiratory tract diseases. Nowadays, coronaviruses - and specifically, SARS-CoV-1, MERS-CoV and SARS-CoV-2 - are the principal responsible for the major epidemic outbreaks of the 21st century. The major routes of transmission for respiratory viruses - including coronaviruses - are via direct and indirect contacts. However, transmission through contaminated foods has not been extensively assessed. The present paper was aimed at reviewing scientific data on the transmission of respiratory viruses through potentially contaminated foods. While the current data seem to suggest that this route of transmission is not likely to occur, in order to increase the knowledge on this issue further investigations are still clearly necessary for a more complete prevention of the risks. Studies should include fresh produce and cooked foods. Anyway, prevention measures and good hygienic practices for both consumers and workers are mandatory when handling and cooking foods.

Examining the persistence of human Coronavirus 229E on fresh produce

Human coronaviruses (HCoVs) are mainly associated with respiratory infections. However, there is evidence that highly pathogenic HCoVs, including severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) and Middle East Respiratory Syndrome (MERS-CoV), infect the gastrointestinal (GI) tract and are shed in the fecal matter of the infected individuals. These observations have raised questions regarding the possibility of fecal-oral route as well as foodborne transmission of SARS-CoV-2 and MERS-CoV. Studies regarding the survival of HCoVs on inanimate surfaces demonstrate that these viruses can remain infectious for hours to days, however, there is limited data regarding the viral survival on fresh produce, which is usually consumed raw or with minimal heat processing. To address this knowledge gap, we examined the persistence of HCoV-229E, as a surrogate for highly pathogenic HCoVs, on the surface of commonly consumed fresh produce, including: apples, tomatoes, cucumbers and lettuce. Herein, we demonstrated that viral infectivity declines within a few hours post-inoculation (p.i) on apples and tomatoes, and no infectious virus was detected at 24h p.i, while the virus persists in infectious form for 72h p.i on cucumbers and lettuce. The stability of viral RNA was examined by droplet-digital RT-PCR (ddRT-PCR), and it was observed that there is no considerable reduction in viral RNA within 72h p.i.

An overview of food safety and COVID-19 infection

Avian influenzas, Ebola, Nipah, Middle East respiratory syndrome coronavirus (MERS-CoV), and severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), which is an RNA virus covered by a lipid bilayer, are directly affecting people worldwide. On the other hand, in addition to the main spread source (human contact) of SARS-CoV-2, consumers have started to think about whether foods are dangerous in terms of SARS-CoV-2 spread. The consumption of wild animals as well as the possible contamination of SARS-CoV-2 in fresh and frozen foods have caused concern and increased awareness among consumers. A heating process >70°C is being suggested to eliminate viral contamination risk. Cutting tools, slicing machines, and food-contact surfaces including stainless steel, aluminum, or glass must be regularly sanitized. The sous vide cooking method, which is based on cooking under vacuum and with pH treatments in the range of 3 and 10, could be advised in this risky period for decreasing contamination risk in food. Also, recent studies have shown that nanotechnology applications such as nanoparticles could be used to combat the SARS-CoV-2 spread, which is 50–200 nm in size. Another suggested technique is cold plasma technology that could damage the protein structure of the virus. Besides these techniques, it is important to boost the immune system. In this regard, recent researches have revealed the importance of honey consumption (1 g/kg per person/day), intake of vitamins, minerals like selenium, and ω-3 fatty acids.