Identification of Enteric Viruses in Foods from Mexico City

Foodborne viruses are a common and, probably, the most under-recognized cause of outbreaks of gastroenteritis. Among the main foods involved in the transmission of human enteric viruses are mollusks, and fruits and vegetables irrigated with wastewater and/or washed with non-potable water or contaminated by contact with surfaces or hands of the infected personnel during its preparation. In this study, 134 food samples were analyzed for the detection of Norovirus, Rotavirus, and Hepatitis A virus (HAV) by amplification of conserved regions of these viruses. From the 134 analyzed samples, 14 were positive for HAV, 6 for Norovirus, and 11 for Rotavirus. This is the first report in Mexico where emphasis is given to the presence of HAV and Norovirus on perishable foods and food from fisheries, as well as Rotavirus on frozen vegetables, confirming the role of vegetables and bivalve mollusks as transmitting vehicles of enteric viruses.     

Isolation and Genomic Sequence of Hepatitis A Virus from Mixed Frozen Berries in Italy

Hepatitis A virus (HAV) was detected in two samples of mixed frozen berries linked to Italian hepatitis A outbreak in April and September 2013. Both viruses were fully sequenced by next-generation sequencing and the genomes clustered with HAV complete genomes of sub-genotype IA with nucleotide identities of 95–97 %.     

First Serological Study of Hepatitis E Virus Infection in Backyard Pigs from Serbia

Hepatitis E virus (HEV) genotype 3 infections in pigs and humans have been lately reported in Europe. In the present study, the prevalence of anti-HEV IgG antibodies in swine was investigated, for the first time, in Serbia by means of an ELISA based on a recombinant open reading frame 2 protein of HEV genotype 3. A total of 315 serum samples from 3 to 4 months-old healthy backyard pigs, collected in 63 herds from 28 towns and villages of 4 different districts of the Vojvodina province, in the northern part of Serbia, were tested. A 34.6% (109/315) of the sera tested were positive. The prevalence of anti-HEV antibodies varied widely between municipalities (range 16.7–75.0%) and herds (range 0–100%). These data indicate that HEV infection is widespread in Serbian backyard pigs.     

Hepatitis A Outbreaks and Environmental Circulation of Genotype IA Strains in the São Paulo City, 2017–2018

Food and Environmental Virology - Hepatitis A virus (HAV) is the major cause of enterically transmitted infectious hepatitis. Between 2016 and 2017, the number of confirmed cases of hepatitis A...     

Detection of Hepatitis A Virus in Strawberries Implicated in an Outbreak in the USA in 1997

Food and Environmental Virology - Hepatitis A virus (HAV) was detected in frozen strawberries which had been implicated in a large outbreak of hepatitis A in 1997. The sample was analysed after...     

Comparative Analysis of Viral Concentration Methods for Detecting the HAV Genome Using Real-Time RT-PCR Amplification

Hepatitis A is a major infectious disease epidemiologically associated with foodborne and waterborne outbreaks. Molecular detection using real-time RT-PCR to detect the hepatitis A virus (HAV) in contaminated vegetables can be hindered by low-virus recoveries during the concentration process and by natural PCR inhibitors in vegetables. This study evaluated three virus concentration methods from vegetables: polyethylene glycol (PEG) precipitation, ultrafiltration (UF), and immunomagnetic separation (IMS). UF was the most efficient concentration method, while PEG and IMS were very low for the recovery rate of HAV. These results demonstrate that UF is the most appropriate method for recovering HAV from contaminated vegetables and that this method combined with the real-time RT-PCR assay may be suitable for routine laboratory use.     

渤海湾天津沿岸海水中甲肝病毒的检测和定量

甲肝病毒（hepatitis A virus, HAV）是能引起传染性甲型肝炎的单链RNA病毒.用常规RT-PCR（反转录PCR）和SYBR Green实时定量RT-PCR方法,根据甲肝病毒保守的VP1-VP2基因序列设计引物,对渤海湾天津沿岸海水中的甲肝病毒进行了检测和定量分析. 9个样品取自渤海湾天津塘沽以南沿岸海水,取样时间分别是2007年夏、秋、冬季和2008年春季. 海水样品先用小型超滤装置（Millipore Pellicon Mini TFF）或超滤离心管（Millipore Centricon Plus-70）浓缩,然后进行RT-PCR检测.结果表明,从9个海水样品中都能扩增出192 bp的HAV cDNA,这些cDNA的核苷酸序列与GenBank中的同源序列相似性为95%～100%. 用SYBR Green 实时定量RT-PCR检测了春季和冬季的6个海水样品,结果表明,海水中甲肝病毒的浓度范围为5.35×10⁶～4.51×10⁷ virus particles/L.     

Viral Removal by Wastewater Treatment: Monitoring of Indicators and Pathogens

The discharge of treated civil wastewater into natural waters or their reuse in industry and agriculture involves virological risks for the exposed population. Although European and Italian regulations do not require routine viral analysis of treated wastewater, a better understanding of viral contamination and resistance to treatments is needed to assess and control such risks. To this end, a wastewater treatment plant was monitored by analysing the sewage at the plant entry and exit points in order to quantify the initial presence and eventual reduction of adenovirus, Torque Teno virus, Hepatitis A virus, rotavirus, enterovirus, norovirus genogroups I and II, somatic coliphages, Escherichia coli and enterococci. The results reveal that treated water may still contain infectious human viruses and thereby represent a potential health hazard. No significant correlations were found between bacterial indicators and the viruses considered, confirming their inadequacy for virological risk assessment, while the best indicators for virus inactivation in recycled waters seem to be adenovirus, followed by somatic coliphages.     

Expression and Immunoreactivities of Hepatitis E Virus Genotype 3 Open Reading Frame-2 (ORF-2) Recombinant Proteins Expressed in Insect Cells

Hepatitis E virus (HEV) is a fecal-orally transmitted virus that is endemic in many geographical areas with poor sanitary conditions and inadequate water supplies. In Europe, a low-endemic area, an increased number of autochthonous sporadic human cases of patients infected with HEV strains of genotype 3, have been reported lately. The relatively high prevalence of HEV genotype 3 infections in European pigs has raised concerns about a potential zoonotic transmission to humans. Determination of HEV seroprevalence in pigs would help to clarify its incidence and possible zoonotic implications. To this purpose, we have expressed and partially characterized swine genotype 3 HEV open reading frame-2 proteins upon infection of Sf21 insect cells with recombinant baculoviruses. The use of the expressed proteins as diagnostic antigens for the detection of antibodies to HEV has been further assayed with human and swine sera.     

Norovirus and Other Human Enteric Viruses in Moroccan Shellfish

The aim of this study was to evaluate the presence of human enteric viruses in shellfish collected along the Mediterranean Sea and Atlantic Coast of Morocco. A total of 77 samples were collected from areas potentially contaminated by human sewage. Noroviruses were detected in 30 % of samples, with an equal representation of GI and GII strains, but were much more frequently found in cockles or clams than in oysters. The method used, including extraction efficiency controls, allowed the quantification of virus concentration. As in previous reports, results showed levels of contamination between 100 and 1,000 copies/g of digestive tissues. Sapoviruses were detected in 13 % of samples mainly in oyster and clam samples. Hepatitis A virus was detected in two samples, with concentrations around 100 RNA copies/g of digestive tissues. Only two samples were contaminated with enterovirus and none with norovirus GIV or Aichi virus. This study highlights the interest of studying shellfish samples from different countries and different production areas. A better knowledge of shellfish contamination helps us to understand virus levels in shellfish and to improve shellfish safety, thus protecting consumers.     

Hepatitis E Virus in Water Environments: A Systematic Review and Meta-analysis

Food and Environmental Virology - Hepatitis E virus (HEV) is responsible for acute hepatitis in humans, through foodborne, zoonotic, and waterborne transmission routes. This study aimed to assess...     

Prevalence of Hepatitis E Virus (HEV) Antibodies in Mexican Pigs

The hepatitis E virus (HEV) is the causative agent of Hepatitis E, an enterically transmitted disease. HEV infections in pigs and humans have been reported worldwide, but data from Mexico are scarce. In the present study, the prevalence of anti-HEV IgG antibodies was investigated in a quite large number of swine from Mexico by means of an ELISA based on a recombinant open reading frame 2 protein of HEV genotype 3. Serum samples from 683 healthy pigs (1–48 months old), collected during 2010–2013 in 109 herds from 48 municipalities located in 9 states in the centre of the country were assayed. A 30.75 % (210/683) of the sera tested were positive, and they were distributed along all the states included in the study. The prevalence of anti-HEV antibodies varied widely between municipalities and herds, and it was higher in pigs 4–6 months of age. No relationships were detected between seroprevalences and farm characteristics. Forty individual faecal samples were analysed by RT-PCR and all resulted negative. These data indicate that HEV infection is widespread in Mexican pigs; thus, representing a potential zoonotic risk for humans.     

Persistence of Hepatitis A Virus in Fresh Produce and Production Environments,and the Effect of Disinfection Procedures: A Review

Although information is limited, it is evident that prolonged persistence of infectious Hepatitis A virus (HAV) is a factor in the transmission of the virus via fresh produce. Consequently, data on persistence of the virus on produce, and in environments relevant to production, such as soils, water and surfaces, are required to fully understand the dynamics of transmission of HAV via foods. Furthermore, information on effective disinfection procedures is necessary to implement effective post-harvest control measures. This review summarises current information on HAV persistence in fresh produce and on relevant disinfection procedures. On vegetables, HAV can remain infectious for several days; on frozen berries, it can persist for several months. HAV can remain infectious on surfaces for months, depending on temperature and relative humidity, and can survive desiccation. It can survive for several hours on hands. Washing hands can remove the virus, but further data are required on the appropriate procedure. Chlorination is effective in water, but not when HAV is associated with foodstuffs. Bleach and other sodium hypochlorite disinfectants at high concentrations can reduce HAV on surfaces, but are not suitable for use on fresh produce. There is only limited information on the effects of heating regimes used in the food industry on HAV. HAV is resistant to mild pasteurisation. Some food components, e.g. fats and sugars, can increase the virus’ resistance to higher temperatures. HAV is completely eliminated by boiling. Quantitative prevalence data are needed to allow the setting of appropriate disinfection log reduction targets for fresh produce.     

Effect of Sodium Chloride,Sodium Nitrite and Sodium Nitrate on the Infectivity of Hepatitis E Virus

Food and Environmental Virology - Hepatitis E virus (HEV) infection can cause acute and chronic hepatitis in humans. The zoonotic HEV genotype 3, which is highly prevalent in Europe, is mainly...     

Hepatitis E Virus in Farmed Rabbits,Wild Rabbits and Petting Farm Rabbits in the Netherlands

Rabbits have been suggested as a zoonotic source of Hepatitis E virus. Phylogenetic analysis of HEV isolates from farmed, wild and pet rabbits in the Netherlands (23, 0, and 60 % respectively) showed them to be grouped amongst published rabbit HEV sequences and distinct from most human isolates. Dutch rabbits are unlikely to be a zoonotic source.     

Stability and self-organization of proteins

X-ray crystallography and NMR provide insight into the three-dimensional structure of proteins at high resolution yielding a relatively small number of stable "topologies". Their free energies of stabilization are minute compared to the total molecular energy. Molecular adaptation to extremes of physical conditions at the protein level refers to marginal alterations of the intramolecular interactions; clearcut predictions with respect to the correlation of protein structure and protein stability are at present not possible. The acquisition of the native structure of proteins is determined by the kinetically accessible minimum of potential energy. The overall mechanism may be described as a hierarchical condensation with elements of secondary/super-secondary structure and subdomains/domains as intermediate stages. In the case of oligomeric and multimeric proteins, folding and association of subunits follow a consecutive uni-bimolecular mechanism, the kinetics of which can be simulated with high precision. The "code of protein folding" is still unknown.     

Detection and Phylogenetic Analysis of the Hepatitis E Virus in a Canadian Swine Production Network

Viral contamination along the production chain is a significant concern in both food safety and livestock health. Pigs have been reported to act as a reservoir for zoonotic viruses, sometimes emerging ones, and epidemiological studies have shown direct links between the consumption of uncooked pork offal and cases of hepatitis caused by the hepatitis E virus (HEV) genotype 3 in humans. The presence of HEV in swine herds has been reported, but its dissemination in pork production environments is still unknown. To investigate viral contamination sources in the swine industry, 452 environment and fecal samples, including samples from livestock transportation vehicles, were collected over a period of 11 months from ten farms and one slaughterhouse that together represent a single production network. Hepatitis E virus RNA was detected by nested RT-PCR in 32 samples from both inside and outside farm buildings, on trucks, and, mostly, from fomites collected in the slaughterhouse yard, such as on a utility vehicle. Phylogenetic analysis showed a wide diversity of HEV genotype 3 strains, similar to human and swine strains previously found. According to the results of this study, the movements of trucks and utility vehicles might play an important role in HEV dissemination on a slaughterhouse site and throughout an entire network.     

Detection of Hepatitis E Virus in Archived Rabbit Serum Samples,Germany 1989

We detected Hepatitis E virus in serum samples of wild rabbits that were hunted in 1989 around the city of Greifswald, Germany. The recovery of one partial sequence and subsequent phylogenetic analysis indicates a close relationship to rabbit HEV sequences from France and suggests a long-established circulation of rabbit HEV in Europe.     

辽东湾沿岸水域甲肝病毒和粪大肠菌群分布

报道了2002年辽东湾3个沿岸海域表层海水中甲肝病毒和粪大肠菌群分布的检测结果。结果显示,5月份表层海水 中没有检出甲肝病毒,粪大肠菌群也符合卫生标准;8月份和10月份表层海水中的甲肝病毒loo％呈阳性,粪大肠菌群均超标。 结果表明,粪大肠菌群指示海水中肠道病毒污染程度仍具有很大程度的可靠性。