Molecular detection and epidemiology of astrovirus, bocavirus, and sapovirus in Italian children admitted to hospital with acute gastroenteritis, 2008-2009

Worldwide prevalence and genotype distribution of human astrovirus in gastroenteritis patients: A systematic review and meta-analysis

AIM

Human astrovirus (HAstV) is an important causative agent of gastroenteritis in humans, which mainly infects young children and the elderly. The goal of this study was to conduct a meta-analytic review of the prevalence of HAstV amongst patients with gastroenteritis, and to shed light on the connection between HAstV infection and gastroenteritis.

METHODS

Systematic literature searches were conducted to identify all potentially relevant studies recorded up to April 8th, 2022. For study weighting, the inverse variance method was employed and the random-effects model was applied to evaluate data. For case-control studies, the pooled odds ratio (OR) and 95% confidence interval (CI) were calculated to establish the relationship between HAstV infection and gastroenteritis.

RESULTS

Among 302423 gastroenteritis patients from 69 different countries, the overall pooled prevalence of HAstV infection was 3.48% (95% CI: 3.11%-3.89%). Case-control approach was used in 39 investigations, and the overall prevalence of HAstV infection among the 11342 healthy controls was 2.01% (95% CI: 1.40%-2.89%). Gastroenteritis and HAstV infection were associated with a pooled OR of 2.16 (95% CI: 1.72-2.71; P < 0.0001; I² = 33.7%). The most commonly found HAstV genotypes in gastroenteritis patients were HAstV1 (62.18%), HAstV7 (33.33%), and HAstV-MLB1 (17.43%).

CONCLUSION

The frequency of HAstV infection was the highest in children under the age of five, and in developing countries. The prevalence rate of HAstV was not influenced by gender. Semi-nested and nested RT-PCR were highly sensitive assays for detecting HAstV infections.

Atypical Viral Infections in Gastroenterology

Enteric viruses are commonly found obligate parasites in the gastrointestinal (GI) tract. These viruses usually follow a fecal-oral route of transmission and are characterized by their extraordinary stability as well as resistance in high-stress environments. Most of them cause similar symptoms including vomiting, diarrhea, and abdominal pain. In order to come in contract with mucosal surfaces, these viruses need to pass the three main lines of defense: mucus layer, innate immune defenses, and adaptive immune defenses. The following atypical gastrointestinal infections are discussed: SARS-CoV2, hantavirus, herpes simplex virus I, cytomegalovirus, and calicivirus. Dysbiosis represents any modification to the makeup of resident commensal communities from those found in healthy individuals and can cause a patient to become more susceptible to bacterial and viral infections. The interaction between bacteria, viruses, and host physiology is still not completely understood. However, with growing research on viral infections, dysbiosis, and new methods of detection, we are getting closer to understanding the nature of these viruses, their typical and atypical characteristics, long-term effects, and mechanisms of action in different organ systems.

Human Astrovirus in Symptomatic and Asymptomatic Children: A Cross-Sectional Study on Hospitalized and Outpatients from Rural Communities of South Africa between 2017-2021

Human astroviruses are considered acute gastroenteritis agents (AGE) and are largely reported in children worldwide. There are limited data on astrovirus prevalence in rural communities, especially in hospitalized and asymptomatic cases. This study was a cross-sectional survey aiming to investigate the prevalence of classic human astroviruses in symptomatic and asymptomatic cases and hospitalized and outpatient children in rural communities of the Vhembe District, South Africa. A total of 236 stool samples (166 symptomatic and 70 asymptomatic) were collected from young children under 5 years of age. Real-time RT-PCR for astrovirus detection, RT-PCR amplification of capsid and polymerase partial genes as well as Sanger sequencing were performed. The classic astrovirus prevalence in symptomatic patients (7.23%, 12/166) as compared to healthy controls (4.29%, 3/70) was not statistically different (t-value: 1.782, p = 0.141: 95% CI). We did not observe a significant difference of classic astrovirus prevalence rate between the hospitalized group (6.52%, 3/46) and outpatient group (7.5%, 9/120). Symptomatic children below 6 months old were the most affected group (18.18%, 6/33). This study characterized human astrovirus genotype 2 and a putative recombinant strain (polymerase genotype 1/capsid genotype 2). Phylogenetic analysis revealed these genotypes are closely related to the strains circulating elsewhere within the African continent. The findings suggest that astrovirus is a common enteric pathogen in the study area. The results highlight the exposure of children and the need to monitor astroviruses for their potential impact in diarrhoeal diseases.

Global molecular prevalence and genotype distribution of Sapovirus in children with gastrointestinal complications: A systematic review and meta-analysis

Sapovirus (SaV) is an emerging cause of children gastrointestinal complications such as acute gastroenteritis (AGE). The aim of the present systematic review and meta-analysis was to estimate the global prevalence of the SaV in children and association of infection with SaVs and AGE in children based on case-control studies. Four international databases (PubMed, Scopus, Web of Sciences and Google Scholar) were used to retrieve English-language studies published between January 2000 and December 2020. Comprehensive Meta-Analysis software was applied to estimate the overall prevalence, publication bias and heterogeneity index. The pooled prevalence of SaV infection among children with gastroenteritis was 3.4% [95% confidence interval (CI): 2.9%-3.9%] based on a random-effects meta-analysis. Genogroup I was the dominant genogroup of SaV in children with gastroenteritis [2.2% (95% CI: 1.6%-3.0%)], association analysis showed that SaV was associated with gastroenteritis [OR: 1.843 (95% CI: 1.27-2.66)]. Given the significant prevalence of the virus in children, it is necessary to pay more attention to this situation. Therefore, preventive health measures in children should be a priority.

Detection of Human Sapoviruses in Sewage in China by Next Generation Sequencing

Human sapovirus (SaV) is an important causative agent of nonbacterial gastroenteritis in humans. However, little is known about its circulation in China. To study the prevalence and diversity of human SaV genotypes circulating in eastern China, a 3-year environmental surveillance combined with next generation sequencing (NGS) technology was conducted. A total of 36 raw sewage samples were collected from January 2017 to December 2019 in Jinan and processed. Thirty-five (97.22%) samples were positive for human SaV genome in quantitative RT-PCR assay; 33 (91.67%) samples were positive in nested RT-PCR assay on partial capsid VP1 sequence and all amplicons were further analyzed separately by NGS. Among those, ten genotypes belonging to the genogroups of GI, GII, GIV, and GV were identified by NGS, including 4 major genotypes (GI.2, GI.1, GV.1 and GI.3) and 6 uncommon genotypes (GII.5, GII.1, GII.NA1, GII.3, GI.6 and GIV.1). A temporal switch of predominant genotype was observed from GI.2 to GI.1 around June 2019. Local and foreign sequences clustered together in some branches according to phylogenetic analysis, indicating frequent transmission of various lineages in different regions of the world. Environmental surveillance provides a comprehensive picture of human SaV in China. NGS-based environmental surveillance improves our knowledge on human SaV circulating in communities greatly and should be encouraged as a sensitive surveillance tool.

Human bocavirus genotypes 1, 2, and 3 circulating in pediatric patients with acute gastroenteritis in Chiang Mai, Thailand, 2012-2018

BACKGROUND

Global distribution of human bocavirus (HBoV) has been known to associate with viral gastroenteritis in pediatric population. This study was conducted in Chiang Mai, Thailand from 2012 to 2018 to investigate epidemiology and genotype distribution of HBoV in pediatric patients less than 5 years old hospitalized with diarrhea.

METHODS

A total of 2727 fecal specimens were investigated for the presence of HBoV using nested-PCR targeting partial VP1 capsid region. The detected HBoV strains were further characterized by nucleotide sequencing and phylogenetic analysis.

RESULTS

Detection rate of HBoV infection in pediatric patients with acute diarrhea was 5.2%. Three genotypes of HBoV were detected with the most predominance of HBoV1 (50.4%), followed by HBoV2 (42.5%), and HBoV3 (7.1%). The majority of HBoV positive cases were children of 1 to <2 years old (31.9%) with high detection rate of HBoV1 and HBoV2. HBoV infection occurred all year-round. Phylogenetic analysis revealed that majority of HBoV1 displayed the genetic relationship with HBoV1 strains reported previously from Asia whereas only a few were related to the strains from Europe, South America, and Middle East. The HBoV2 and HBoV3 were also mainly closely related to the strains reported from Asia and a few from South America and North Africa.

CONCLUSIONS

This study highlights distribution of HBoV genotypes circulating in pediatric patients with acute gastroenteritis in Chiang Mai, Thailand. Overall, three genotypes of HBoV were detected with equally high prevalence of HBoV1 and HBoV2 whereas HBoV3 was detected with much lower prevalence.

Genetic Diversity of Sapoviruses among Inpatients in Germany, 2008-2018

Sapovirus enteric disease affects people of all ages across the globe, in both sporadic cases and outbreak settings. Sapovirus is seldom assessed in Germany and its epidemiology in the country is essentially unknown. Thus, sapovirus occurrence and genetic diversity were studied by real-time reverse transcription polymerase chain reaction (RT-PCR) and partial sequencing of major viral structural protein (VP1) gene in two different sets of stool samples: (1) a selection of 342 diarrheal stools collected from inpatient children during 2008−2009, and (2) 5555 stool samples collected during 2010–2018 from inpatients of all age groups with gastrointestinal complaints. Results showed year-round circulation of sapoviruses, with peaks during cooler months. In total, 30 samples (8.8%) of the first and 112 samples of the second set of samples (2.0%) were sapovirus positive. Capsid gene sequencing was successful in 134/142 samples (94.4%) and showed circulation of all known human pathogenic genogroups. Genotype GI.1 predominated (31.8%), followed by GII.1 (16.7%), GII.3 (14.5%), GI.2 (13.8%) and GV.1 (12.3%). Additionally, minor circulation of GI.3, GI.6, GII.2, GII.4, GII.6 and GIV.1 was shown. Consequently, sapovirus diagnostics need broadly reactive RT-PCR protocols and should particularly be considered in infants and young children. Further studies from other sampling sites are essential to extend our knowledge on sapovirus epidemiology in Germany.

Human sapovirus GI.2 and GI.3 from children with acute gastroenteritis in northern Brazil

Human sapoviruses (HSaV) are considered important causative agents of acute gastroenteritis in humans worldwide. However, knowledge of the genetic characteristics of the whole genome of HSaV in Brazil is limited. Here we report the complete genome sequences of six HSaVs GI.2 and two GI.3 strains obtained from children with acute gastroenteritis in the Northern region of Brazil. Next generation sequencing was used to obtain the full genome and molecular characterization of the genome was performed. Phylogenetic analysis of the genome was also performed. Only one complete HSaV GI.2 genome characterization in the country precedes that of the present study. This is the first complete genome sequence of genotype GI.3 in Brazil. The data obtained in this investigation can contribute to the augmentation of the database on the molecular diversity of HSaVs strains circulating in Brazil, and to the improvement of current typing protocols.

Molecular epidemiology of classic, MLB and VA astroviruses isolated from <5 year-old children with gastroenteritis in Thailand, 2011-2016

This study aimed to investigate the molecular epidemiology and genetic diversity of astrovirus circulating in pediatric patients with acute gastroenteritis in Thailand. A total of 2034 fecal specimens collected between 2011 and 2016 from children hospitalized with acute gastroenteritis were analyzed for astrovirus infection using RT-PCR and nucleotide sequencing techniques. Overall, 54 samples were positive for astrovirus (2.6%). About half of the virus-positive samples (57.4%) were co-infection cases, mainly with rotavirus or norovirus. Genotyping revealed that three major clades, classic human astrovirus (HAstV) and newly emerging MLB and VA astroviruses co-circulated in the study population. At least seven different genotypes were identified and HAstV1 was the most predominant genotype detected (50%), followed by MLB1 (16.7%), HAstV4 (11.1%), HAstV5 and HAstV8 (7.4% each), MLB2 and VA2 (3.7% each). This study provided a useful information and contributed to molecular epidemiology of astroviruses including the novel MLB and VA astoviruses have been characterized and reported for the first time in Thailand.

Molecular Detection of Human Astrovirus in Children With Gastroenteritis, Northern Italy

BACKGROUND

Human astroviruses have increasingly been identified and are important agents of diarrheal disease, especially in infants and young children. This article presents the real-time polymerase chain reaction TaqMan assay for the detection and quantification of human astrovirus for clinical fecal samples collected from hospitalized children with acute gastroenteritis in Piedmont (northern Italy) from December 2014 to November 2015.

METHODS

A total of 159 fecal specimens from hospitalized children with acute gastroenteritis, previously screened for rotavirus, adenovirus, norovirus, human parechovirus, salivirus and sapovirus, were tested for human astrovirus.

RESULTS

The most commonly detected virus was norovirus GII (33.8%), followed by rotavirus (21.3%), sapovirus (10.9%), human parechovirus (8%), norovirus GI (6.7%), adenovirus (1%) and salivirus (0.52%). A total of 30 of 159 (18.87%) episodes of acute gastroenteritis were associated with human astrovirus genomic detection.

CONCLUSIONS

Our data showed that the detection rate of astrovirus in diarrheal children (18.87%) was higher than observed in other countries, where they were reported in diarrheal children in 10.3%-0.8% of patients and a mean incidence worldwide of 11%. Our data showed that the detection rate of astrovirus in pediatric gastroenteritis was greater than previously reported in Italy.

Contribution of the FilmArray® Gastrointestinal Panel in the laboratory diagnosis of gastroenteritis in a cohort of children: a two-year prospective study

This study represents a 2-year picture of the epidemiology of enteric pathogens in children suffering from gastroenteritis using the FilmArray® Gastrointestinal Panel (FA-GP), a multiplex molecular assay that allows to simultaneously detect a large panel of pathogens independently of the etiological suspicion and to evaluate its potential contribution to the diagnosis compared to the conventional methods. A total of 1716 stool samples, collected from children with clinical suspicion of bacterial and/or viral gastroenteritis attending the University Hospital of Parma, was submitted to the FA-GP and, when an adequate aliquot was available, to electron microscopy (n = 1163) for virus detection and to an enterovirus-targeting real-time PCR (n = 1703). Specimens with positive results for Salmonella, Yersinia enterocolitica, Vibrio, diarrheagenic Escherichia coli/Shigella, Campylobacter, Plesiomonas shigelloides and/or parasites by the FA-GP were also submitted to conventional diagnostic methods. The FA-GP gave positive results in 958 (55.8%) cases, 64.8% from inpatients: 647 (67.5%) contained a single agent and 311 (32.5%) multiple agents, for a total of 1374 pathogens. Enteropathogenic E. coli, rotavirus, norovirus, toxigenic Clostridioides difficile, and sapovirus were the most commonly detected pathogens. A total of 812 additional agents (344 of which as single pathogen) was detected by the FA-GP and not included in the clinical suspicion. The overall recovery rate of the conventional methods from stools that resulted positive by the FA-GP was 38.6% for bacteria, 50% and 84.2% for Giardia intestinalis and Cryptosporidium, respectively, and ranged from 3.7% to 64.6% for viruses, if excluding all electron microscopy-negative astroviruses. Enterovirus, an agent not targeted by the FA-GP, was revealed in 9.6% (164/1703) of the examined samples, and in 52 cases it was the only agent detected. The results of this study allowed to extend the range of detectable pathogens independently of the clinical suspicion, to detect co-infections in almost one third of children positive for at least one agent and to show that conventional methods would have missed more than half of the enteric agents detected by the FA-GP.

Co-circulation of classic and novel astrovirus strains in patients with acute gastroenteritis in Germany

OBJECTIVES

In order to analyze the molecular epidemiology of human astroviruses (HAstV) in Germany, a retrospective long-term study was performed to characterize circulating human astrovirus in patients with acute gastroenteritis in Germany.

METHODS

A total of 2877 stool samples, collected between January 2010 and December 2015 from sporadic cases and outbreaks of acute gastroenteritis were retrospectively analyzed for astrovirus. A two-step PCR algorithm was developed and used to identify and characterize human astrovirus infections.

RESULTS

Overall, 143 samples were astrovirus-positive (5.0%). Astrovirus infection was most frequently detectable in samples from children of 3-4 years (15%) followed by children of 1-2 years (8.6%), detection rates in adults were lower (1%-3.6%). A high number (71.3%) of co-infections, mainly with noro- or rotaviruses, were identified. Genotyping revealed that at least ten genotypes from all four human MAstV species were circulating in the study population. HAstV-1 was predominant in different age groups. Novel HAstV (MLB and VA genotypes) were also circulating in Germany.

CONCLUSION

Our findings give new insights into the circulation and genetic diversity of human astroviruses in patients with acute gastroenteritis. The novel HAstV-MLB and -VA genotypes could be characterized firstly in Germany while the analysis showed that these viruses have been dispersed in Germany since 2011 as a causative agent of acute gastroenteritis.

Aichivirus in Children with Diarrhea in Northern Italy

OBJECTIVE

Since its discovery, Aichivirus (AiV) A has been detected, with an incidence of 0.9-4.1%, primarily when studying outbreaks of diarrhea in children or young adults. In this paper, we report the first detection of AiV in Piedmont, Italy, in pediatric patients.

METHODS

A total of 159 fecal specimens (from 96 males and 63 females) previously screened for rotaviruses, adenoviruses, noroviruses, human parechoviruses, saliviruses, and sapoviruses were collected from infants and children with acute gastroenteritis.

RESULTS

The most commonly detected virus was norovirus GII (33.80%), fol lowed by rotavirus (21.30%), astrovirus (18.87%), boca virus (13.92%), sapovirus (10.90%), parechovirus (8%), norovirus GI (6.70%), adenovirus (1%), and salivirus (0.52%). Real-time polymerase chain reaction detected AiV A in 1 (0.62%) case subjects. AiV A was detected in monoinfection only in January.

CONCLUSIONS

Our results indicate that AiV may be associated with a limited number of diarrhea cases in pediatric patients.

Sapovirus in Wastewater Treatment Plants in Tunisia: Prevalence, Removal, and Genetic Characterization

Sapovirus (SaV), from the Caliciviridae family, is a genus of enteric viruses that cause acute gastroenteritis. SaV is shed at high concentrations with feces into wastewater, which is usually discharged into aquatic environments or reused for irrigation without efficient treatments. This study analyzed the incidence of human SaV in four wastewater treatment plants from Tunisia during a period of 13 months (December 2009 to December 2010). Detection and quantification were carried out using reverse transcription-quantitative PCR (RT-qPCR) methods, obtaining a prevalence of 39.9% (87/218). Sixty-one positive samples were detected in untreated water and 26 positive samples in processed water. The Dekhila plant presented the highest contamination levels, with a 63.0% prevalence. A dominance of genotype I.2 was observed on 15 of the 24 positive samples that were genetically characterized. By a Bayesian estimation algorithm, the SaV density in wastewater was estimated using left-censored data sets. The mean value of log SaV concentration in untreated wastewater ranged between 2.7 and 4.5 logs. A virus removal efficiency of 0.2 log was calculated for the Dekhila plant as the log ratio posterior distributions between untreated and treated wastewater. Multiple quantitative values obtained in this study must be available in quantitative microbial risk assessment in Tunisia as parameter values reflecting local conditions.IMPORTANCE Human sapovirus (SaV) is becoming more prevalent worldwide and organisms in this genus are recognized as emerging pathogens associated with human gastroenteritis. The present study describes novel findings on the prevalence, seasonality, and genotype distribution of SaV in Tunisia and Northern Africa. In addition, a statistical approximation using Bayesian estimation of the posterior predictive distribution ("left-censored" data) was employed to solve methodological problems related with the limit of quantification of the quantitative PCR (qPCR). This approach would be helpful for the future development of quantitative microbial risk assessment procedures for wastewater.

The Role of the Human Bocavirus (HBoV) in Respiratory Infections

The human bocavirus is one of the most common respiratory viruses and occurs in all age groups. Because Koch’s postulates have been fulfilled unintendedly, it is currently accepted that the virus is a real pathogen associated with upper and lower respiratory tract infections causing clinical symptoms ranging from a mild common cold to life-threatening respiratory diseases. In order to exclude a viremia, serological analysis should be included during laboratory diagnostics, as acute and chronic infections cannot be differentiated by detection of viral nucleic acids in respiratory specimen alone due to prolonged viral shedding. Besides its ability to persist, the virus appears to trigger chronic lung disease and increases clinical symptoms by causing fibrotic lung diseases. Due to the lack of an animal model, clinical trials remain the major method for studying the long-term effects of HBoV infections.

Comprehensive Analysis of Prevalence, Epidemiologic Characteristics, and Clinical Characteristics of Monoinfection and Coinfection in Diarrheal Diseases in Children in Tanzania

The role of interactions between intestinal pathogens in diarrheal disease is uncertain. From August 2010 to July 2011, we collected stool samples from 723 children admitted with diarrhea (cases) to 3 major hospitals in Dar es Salaam, Tanzania, and from 564 nondiarrheic children (controls). We analyzed the samples for 17 pathogens and assessed interactions between coinfections in additive and multiplicative models. At least one pathogen was detected in 86.9% of the cases and 62.8%, of the controls. Prevalence of coinfections was 58.1% in cases and 40.4% in controls. Rotavirus, norovirus genogroup II, Cryptosporidium, and Shigella species/enteroinvasive Escherichia coli were significantly associated with diarrhea both as monoinfections and as coinfections. In the multiplicative interaction model, we found 2 significant positive interactions: rotavirus + Giardia (odds ratio (OR) = 23.91, 95% confidence interval (CI): 1.21, 470.14) and norovirus GII + enteroaggregative E. coli (OR = 3.06, 95% CI: 1.17, 7.98). One significant negative interaction was found between norovirus GII + typical enteropathogenic E. coli (OR = 0.09, 95% CI: 0.01, 0.95). In multivariate analysis, risk factors for death were presence of blood in stool and severe dehydration. In conclusion, coinfections are frequent, and the pathogenicity of each organism appears to be enhanced by some coinfections and weakened by others. Severity of diarrhea was not affected by coinfections.

Identification of sapovirus GV.2, astrovirus VA3 and novel anelloviruses in serum from patients with acute hepatitis of unknown aetiology

Hepatitis is a general term meaning inflammation of the liver, which can be caused by a variety of viruses. However, a substantial number of cases remain with unknown aetiology. We analysed the serum of patients with clinical signs of hepatitis using a metagenomics approach to characterize their viral species composition. Four pools of patients with hepatitis without identified aetiological agents were evaluated. Additionally, one pool of patients with hepatitis E (HEV) and pools of healthy volunteers were included as controls. A high diversity of anelloviruses, including novel sequences, was found in pools from patients with hepatitis of unknown aetiology. Moreover, viruses recently associated with gastroenteritis as sapovirus GV.2 and astrovirus VA3 were also detected only in those pools. Besides, most of the HEV genome was recovered from the HEV pool. Finally, GB virus C and human endogenous retrovirus were found in the HEV and healthy pools. Our study provides an overview of the virome in serum from hepatitis patients suggesting a potential role of these viruses not previously described in cases of hepatitis. However, further epidemiologic studies are necessary to confirm their contribution to the development of hepatitis.

Epidemiology and genetic diversity of classic human astrovirus among hospitalized children with acute gastroenteritis in Uruguay

Classic Human Astrovirus (Classic HAstV) are one of the most important causes of pediatric acute gastroenteritis (AGE), after rotaviruses and arguably caliciviruses. The aim of this study was to determine the molecular epidemiology of Classic HAstV from 175 clinical samples, being 153 stools and 22 vomits, collected from pediatric hospitalized patients with AGE in Salto city, Uruguay, from January 2011 to December 2012. Classic HAstV were detected and genotyped by using a qualitative Retro Transcription-Polimerase Chain Reaction (RT-PCR) directed to the Open Reading Frame-2 (ORF2) region C. Amplicons were sequenced and phylogenetic analyses were carried out in order to determine genotypes and lineages. Classic HAstV were detected in 18 out of 175 analyzed samples (10.3%) and 14 of them (78.0%) were successfully sequenced being 6 (42.8%) classified as HAstV-1 (1a lineage), 4 (28.6%) as HAstV-2 (2c lineage), and 4 (28.6%) as HAstV-3 (3c lineage). A higher detection of Classic HAstV infections was observed in autumn for both years of surveillance, and the majority of the positive cases were observed in 2011. The group of children between 2 and 5 years old presented the higher percentage of infections. To our knowledge, the present study represents the first report of astrovirus from acute gastroenteritis cases in Uruguay, evidencing its role as a relevant etiologic agent in severe cases of this disease.

Identification and molecular characterization of novel primate bocaparvoviruses from wild western lowland gorillas of Moukalaba-Doudou National Park, Gabon

Bocaparvoviruses have been studied extensively owing to their ability to cause respiratory illness or gastroenteritis in humans. Some bocaparvoviruses have been detected in non-human primates (gorillas and chimpanzees), but the diversity and evolution of these viruses are not fully understood. In this study, we collected 107 fecal samples from wild western lowland gorillas in Moukalaba-Doudou National Park in Gabon to investigate the presence of bocaparvoviruses. Using a combination of pan-bocaparvovirus PCR and individual identification by microsatellite genotyping, we found that two samples from two apparently healthy infant gorillas were positive for bocaparvovirus. Sequencing and phylogenetic analyses revealed that the two gorilla bocaparvovirus strains are nearly identical and are closely related to viruses in the species Primate bocaparvovirus 2 (with 86.0% nucleotide identity to a human bocavirus 2 isolate). To our knowledge, this is the first report showing the presence of a non-human primate bocaparovirus within Primate bocaparvovirus 2. Our findings provide novel insights into the diversity and evolution of bocaparvoviruses and highlight the importance of surveying these viruses for the safe management of gorilla-based ecotourism.

Epidemiology of Classic and Novel Human Astrovirus: Gastroenteritis and Beyond

Since they were identified in 1975, human astroviruses have been considered one of the most important agents of viral acute gastroenteritis in children. However, highly divergent astroviruses infecting humans have been recently discovered and associated with extra-intestinal infections. The report of cases of fatal meningitis and encephalitis, especially in immunocompromised individuals, has broadened their disease spectrum. Although zoonotic transmission among animal and human astroviruses has not been clearly recognized, the genetic similarity between some human and animal viruses makes it likely to occur. This review provides an update on the epidemiology of both classic and novel human astroviruses, and a comprehensive view on confirmed or potential association between astrovirus and human disease.

Frequent Detection and Genetic Diversity of Human Bocavirus in Urban Sewage Samples

The prevalence and genetic diversity of human bocaviruses (HBoVs) in sewage water samples are largely unknown. In this study, 134 raw sewage samples from 25 wastewater treatment plants (WTPs) in Italy were analyzed by nested PCR and sequencing using species-specific primer pairs and broad-range primer pairs targeting the capsid proteins VP1/VP2. A large number of samples (106, 79.1 %) were positive for HBoV. Out of these, 49 were classified as HBoV species 2, and 27 as species 3. For the remaining 30 samples, sequencing results showed mixed electropherograms. By cloning PCR amplicons and sequencing, we confirmed the copresence of species 2 and 3 in 29 samples and species 2 and 4 in only one sample. A real-time PCR assay was also performed, using a newly designed TaqMan assay, for quantification of HBoVs in sewage water samples. Viral load quantification ranged from 5.51E+03 to 1.84E+05 GC/L (mean value 4.70E+04 GC/L) for bocavirus 2 and from 1.89E+03 to 1.02E+05 GC/L (mean value 2.27E+04 GC/L) for bocavirus 3. The wide distribution of HBoV in sewages suggests that this virus is common in the population, and the most prevalent are the species 2 and 3. HBoV-4 was also found, representing the first detection of this species in Italy. Although there is no indication of waterborne transmission for HBoV, the significant presence in sewage waters suggests that HBoV may spread to other water environments, and therefore, a potential role of water in the HBoV transmission should not be neglected.

Epidemiological profile and genetic diversity of sapoviruses (SaVs) identified in children suffering from acute gastroenteritis in Pune, Maharashtra, Western India, 2007–2011

Sapoviruses (SaVs) are responsible for sporadic cases and outbreaks of acute gastroenteritis. Despite this, few studies in India have focused on the epidemiological investigation of SaV in cases of acute gastroenteritis. The aim of this study was to understand the molecular epidemiology, genetic diversity and clinical impact of SaV in diarrhoeic children from Pune, Western India. Between 2007 and 2011, a total of 985 faecal samples from diarrhoeic cases and non-diarrhoeic controls were collected and examined for the presence of SaV by nested RT–PCR. SaV was detected in 2·7% (21/778) of the cases and 1·9% (4/207) of the controls. We observed that the majority of SaV mono-infections caused severe gastroenteritis (67%) with clinical manifestations of diarrhoea (100%), vomiting (73%) and dehydration (80%). All known human SaV genogroups were detected in the study. At least eight genotypes were identified from cases and controls. Genogroups GIV and GV, along with genotypes GI.5, GII.4 and GII.6, were discovered for the first time in India. Two GII.4 study strains were found to be 98·5–99% identical, having a novel intra-genogroup recombinant (GII.1/GII.4) recently reported from the Philippines, suggesting probable evidence of recombination. The circulation pattern of SaV genotypes varied during the study period, with GII.1 being predominant in 2007 and 2009, GIV.1 in 2008, and GV.1 in 2011.

Narrowing of the Diagnostic Gap of Acute Gastroenteritis in Children 0-6 Years of Age Using a Combination of Classical and Molecular Techniques, Delivers Challenges in Syndromic Approach Diagnostics

BACKGROUND

Twenty-five percent to 50% of acute gastroenteritis (AGE) cases remain etiologically undiagnosed. Our main aim was to determine the most appropriate list of enteric pathogens to be included in the daily diagnostics scheme of AGE, ensuring the lowest possible diagnostic gap.

METHODS

Two hundred ninety seven children ≤6 years of age, admitted to hospital in Slovenia, October 2011 to October 2012, with AGE, and 88 ≤6 years old healthy children were included in the study. A broad spectrum of enteric pathogens was targeted with molecular methods, including 8 viruses, 6 bacteria and 2 parasites.

RESULTS

At least one enteric pathogen was detected in 91.2% of cases with AGE and 27.3% of controls. Viruses were the most prevalent (82.5% and 15.9%), followed by bacteria (27.3% and 10.2%) and parasites (3.0% and 1.1%) in cases and controls, respectively. A high proportion (41.8%) of mixed infections was observed in the cases. For cases with undetermined etiology (8.8%), stool samples were analyzed with next generation sequencing, and a potential viral pathogen was detected in 17 additional samples (5.8%).

CONCLUSIONS

Our study suggests that tests for rotaviruses, noroviruses genogroup II, adenoviruses 40/41, astroviruses, Campylobacter spp. and Salmonella sp. should be included in the initial diagnostic algorithm, which revealed the etiology in 83.5% of children tested. The use of molecular methods in diagnostics of gastroenteritis is preferable because of their high sensitivity, specificity, fast performance and the possibility of establishing the concentration of the target. The latter may be valuable for assessing the clinical significance of the detected enteric, particularly viral pathogens.

Epidemiology of Acute Gastroenteritis Outbreaks Caused by Human Calicivirus (Norovirus and Sapovirus) in Catalonia: A Two Year Prospective Study, 2010-2011

Background

The epidemiology of cases of acute gastroenteritis (AGE) of viral etiology is a relevant public health issue. Due to underreporting, the study of outbreaks is an accepted approach to investigate their epidemiology. The objective of this study was to investigate the epidemiological characteristics of AGE outbreaks due to norovirus (NoV) and sapovirus (SV) in Catalonia.

Material and Methods

Prospective study of AGE outbreaks of possible viral etiology notified during two years in Catalonia. NoV and SV were detected by real time reverse transcription polymerase (RT-PCR).

Results

A total of 101 outbreaks were registered affecting a total of 2756 persons and 12 hospitalizations (hospitalization rate: 0.8x1,000,000 persons-year); 49.5% of outbreaks were foodborne, 45.5% person to person and 5% waterborne. The distribution of outbreaks according to the setting showed a predominance of catering services (39.6%), nursing homes and long term care facilities (26.8%) and schools (11.9%). The median number of cases per outbreak was 17 (range 2–191). The total Incidence rate (IR) was 18.3 per 100,000 persons-years (95%CI: 17.6–19.0). The highest IR was in persons aged ≥65 years (43.6x100,000 (95% CI: 41.0–46.2)) (p<0.001). A total of 1065 samples were analyzed with a positivity rate of 60.8%. 98% of positive samples were NoV (GII 56.3%; GI 4.2%; GII+GI 4.2%; non- typable 33.0%). SV was identified in two person-to-person transmission outbreaks in children.

Conclusions

These results confirm the relevance of viral AGE outbreaks, both foodborne and person-to-person, especially in institutionalized persons. SV should be taken into account when investigating viral AGE outbreaks.

Epidemics of GI.2 sapovirus in gastroenteritis outbreaks during 2012-2013 in Osaka City, Japan

Sapovirus (SaV) is a causative agent of gastroenteritis in humans in both sporadic cases and outbreaks. During the period from January 2005 to August 2014, SaV was detected in 30 (5.9%) of 510 gastroenteritis outbreaks in Osaka City, Japan using real-time RT-PCR. Seasonal distribution of SaV-associated outbreaks revealed an increase during the 2011-2012 season and the highest frequency of outbreaks during the 2012-2013 season. Genotyping analysis based on the capsid region demonstrated that the most common genotype was GI.2 (36.7%), in which the strains were closely related. The comparison of complete capsid gene sequences with 18 GI.2 strains (7 strains in this study and 11 from GenBank) between 1990 and 2013 showed that GI.2 strains were classified into at least three genetic clusters (1990-2000, 2004-2007, and 2008-2013) with chronologically unique amino acid residues and accumulation of mutations in the predicted P domain, suggesting the one of the causes of emergence and spread of GI.2 strains. This study will also be helpful for understanding the evolutionary mechanism of the SaV genome.

Respiratory infections of the human bocavirus

The human bocavirus is one of the most common respiratory viruses and occurs in all age groups. It is associated with upper and lower respiratory tract infections, and causes clinical symptoms from the mild common cold to life threatening respiratory diseases. Besides its ability to persist the virus appears to trigger chronic lung disease and increase the clinical symptoms, while being a putative trigger for fibrotic lung diseases.

Laboratory diagnostics should include serological diagnostics in order to rule out a viremia because due to prolonged viral shedding acute and chronic infections cannot be differentiated on the detection of viral nucleic acids in respiratory specimen alone.

Although Koch’s postulates cannot be formally fulfilled due to the lack of an animal model and the chance for clinical trials with volunteers are limited due to the long term effects of HBoV infections, there is no doubt that the virus is a serious pathogen and requires attention.

The aim of the chapter is to present an overview of our current knowledge on respiratory infections with the human bocavirus, and to provide basic and essential information on clinical features, molecular diagnostics, and epidemiologic challenges arising with this pathogen.

Molecular epidemiology of norovirus in children and the elderly in Atlanta, Georgia, United States

Noroviruses are an important cause of gastroenteritis, which can be severe at the extremes of ages. Data documenting the endemic burden of norovirus among children and elderly adults are lacking. Stool specimens submitted for clinical testing were collected from elderly (≥ 65 years) adults and children (<18 years) with acute vomiting and/or diarrhea seeking care at several metropolitan Atlanta adult and pediatric hospitals from January 2013-June 2013. Specimens were tested for norovirus with real-time RT-PCR and sequenced if norovirus was detected. Corresponding clinical and demographic data were abstracted from retrospective chart review. Norovirus was detected in 11% (11/104) of elderly specimens and 11% (67/628) of pediatric, with GII.4 Sydney_2012 detected in 64% (7/11) of elderly norovirus-positive and 11% (8/67) of pediatric specimens, P < 0.001. In comparison to hospitalized children, hospitalized elderly with norovirus were more commonly admitted to the intensive care unit (ICU) (36% vs. 7%, P = 0.02). Norovirus in the elderly can be associated with severe illness requiring ICU admissions. The pediatric group demonstrated greater variability in genotype distribution. Ongoing surveillance of norovirus genotypes is crucial for norovirus vaccine development in understanding circulating and emerging genotypes.

Comprehensive review of human sapoviruses

Sapoviruses cause acute gastroenteritis in humans and animals. They belong to the genus Sapovirus within the family Caliciviridae. They infect and cause disease in humans of all ages, in both sporadic cases and outbreaks. The clinical symptoms of sapovirus gastroenteritis are indistinguishable from those caused by noroviruses, so laboratory diagnosis is essential to identify the pathogen. Sapoviruses are highly diverse genetically and antigenically. Currently, reverse transcription-PCR (RT-PCR) assays are widely used for sapovirus detection from clinical specimens due to their high sensitivity and broad reactivity as well as the lack of sensitive assays for antigen detection or cell culture systems for the detection of infectious viruses. Sapoviruses were first discovered in 1976 by electron microscopy in diarrheic samples of humans. To date, sapoviruses have also been detected from several animals: pigs, mink, dogs, sea lions, and bats. In this review, we focus on genomic and antigenic features, molecular typing/classification, detection methods, and clinical and epidemiological profiles of human sapoviruses.

Genetic heterogeneity and recombination in type-3 human astroviruses

Human astroviruses (HAstVs) are important enteric pathogens and can be classified genetically and antigenically into eight types. During molecular surveillance for HAstVs in Italy, sequence analysis of the diagnostic region C (about 400 nucleotide in length), located on the capsid (ORF2) gene, identified a novel type-3 strain. Upon sequencing of the full-length ORF2, the type-3 HAstV strain was characterized as a novel ORF2 genetic lineage, designated as 3c. By converse, in the ORF1b the virus was more similar to type-1 HAstVs, rather than to type-3 strains, suggesting a recombination nature, with the crossover site being mapped to the ORF1b/ORF2 junction region. Region C sequences of similar type-3 HAstV identified from European and extra-European countries were retrieved in the databases, suggesting the global distribution of this novel type-3 lineage.

Environmental Assessment of Classical Human Astrovirus in Uruguay

The aim of this study was to determine the molecular epidemiology of classical human astrovirus (HAstV) strains in sewage samples from four Uruguayan cities: Bella Unión, Salto, Paysandú, and Fray Bentos, located in the Northwestern region of the country. Overall, 96 sewage samples were collected biweekly between March 2011 and February 2012 and were subject to ultracentrifugation methodology in order to concentrate the viruses. RT-PCR directed to the ORF2 genome region was performed followed by sequencing and phylogenetic analysis. Forty-three (45 %) out of 96 analyzed samples were positive for HAstV (Mamastrovirus 1) and 31 of them were successfully sequenced being 21 (49 %) of them classified as HAstV-1 genotype (1a lineage) and 10 (23 %) as HAstV-2 genotype (eight strains belonging to the 2d lineage and two strains to the 2c lineage). The 1a lineage circulated throughout the year, while the 2d lineage only in the coldest months (June to October). Strikingly, the 2c lineage was detected only in Salto city during March 2011. In this city it was observed the highest frequency of HAstV and the greatest genetic diversity, probably due to its role as high touristic spot with an important influx of visitants from others regions of Uruguay and also from other countries. This study constitutes the first report in Uruguay that describes the phylogenetic diversity and genotype distribution of HAstV strains circulating in the Northwestern region evidencing a high frequency and also the presence of several different lineages.

Complete Genome Sequence of a Novel GV.2 Sapovirus Strain, NGY-1, Detected from a Suspected Foodborne Gastroenteritis Outbreak

Sapoviruses, members of the family Caliciviridae, are genetically highly diverse. We report here the first complete genome sequence of a genogroup V genotype 2 sapovirus strain, NGY-1, detected from fecal samples of a suspected foodborne gastroenteritis outbreak, determined using a metagenomic sequencing approach.

The Detection Rate of Enteric Viruses and Clostridium difficile in a Waste Water Treatment Plant Effluent

Waste water treatment plant (WWTP) is considered as an important source of surface water contamination by enteric pathogens. In this study, we describe the occurrence of enteric viruses (group A rotaviruses, noroviruses, astroviruses, sapoviruses, hepatitis A virus, and hepatitis E virus) and Clostridium difficile in the effluent of a wastewater treatment plant during a 1-year period. Enteric viruses were simultaneously and efficiently concentrated in a single step using methacrylate monolithic chromatographic support. Rotaviruses, noroviruses (genogroup I and II), and sapoviruses were detected in all 12 concentrated samples, whereas astroviruses were not detected in August and September and hepatitis A and E viruses were not detected at all. Clostridium difficile was detected in all samples and altogether 121 strains were isolated and grouped into 32 different ribotypes of which 014/020 and 010 were most prevalent. Pathogens detected in WWTP effluent partially reflect the epidemiological situation of enteric viruses and C. difficile in human population and open the discussion on implementation of possible techniques for virus and bacteria removal from WWTP effluent prior to release into the surface water system.

Analysis of the ORF2 of human astroviruses reveals lineage diversification, recombination and rearrangement and provides the basis for a novel sub-classification system

Canonical human astroviruses (HAstVs) are important enteric pathogens that can be classified genetically and antigenically into eight types. Sequence analysis of small diagnostic regions at either the 5' or 3' end of ORF2 (capsid precursor) is a good proxy for prediction of HAstV types and for distinction of intratypic genetic lineages (subtypes), although lineage diversification/classification has not been investigated systematically. Upon sequence and phylogenetic analysis of the full-length ORF2 of 86 HAstV strains selected from the databases, a detailed classification of HAstVs into lineages was established. Three main lineages could be defined in HAstV-1, four in HAstV-2, two in HAstV-3, three in HAstV-4, three in HAstV-5 and two in HAstV-6. Intratypic (inter-lineages) ORF2 recombinant strains were identified in type 1 (1b/1d) and type 2 (2c/2b) with distinct crossover points. Other potential intratypic recombinant strains were identified in type 3, type 5 and type 6. In addition, a type-1b strain with a large insertion (~600 bp) of heterologous RNA in the N-terminal region and a type-6 strain with a large RNA rearrangement in the hypervariable region were identified. The classification scheme was integrated in a novel nomenclature system suitable for designation of HAstV strains.

Human astroviruses

Human astroviruses (HAtVs) are positive-sense single-stranded RNA viruses that were discovered in 1975. Astroviruses infecting other species, particularly mammalian and avian, were identified and classified into the genera Mamastrovirus and Avastrovirus. Through next-generation sequencing, many new astroviruses infecting different species, including humans, have been described, and the Astroviridae family shows a high diversity and zoonotic potential. Three divergent groups of HAstVs are recognized: the classic (MAstV 1), HAstV-MLB (MAstV 6), and HAstV-VA/HMO (MAstV 8 and MAstV 9) groups. Classic HAstVs contain 8 serotypes and account for 2 to 9% of all acute nonbacterial gastroenteritis in children worldwide. Infections are usually self-limiting but can also spread systemically and cause severe infections in immunocompromised patients. The other groups have also been identified in children with gastroenteritis, but extraintestinal pathologies have been suggested for them as well. Classic HAstVs may be grown in cells, allowing the study of their cell cycle, which is similar to that of caliciviruses. The continuous emergence of new astroviruses with a potential zoonotic transmission highlights the need to gain insights on their biology in order to prevent future health threats. This review focuses on the basic virology, pathogenesis, host response, epidemiology, diagnostic assays, and prevention strategies for HAstVs.

Assessment of gastroenteric viruses from wastewater directly discharged into Uruguay River, Uruguay

The aim of this study was to assess the viral contamination of group A rotavirus (RVA), norovirus (NoV), and human astrovirus (HAstV) in sewage directly discharged into Uruguay River and to characterize RVA genotypes circulating in Uruguay. For this purpose, sewage samples (n = 96) were collected biweekly from March 2011 to February 2012 in four Uruguayan cities: Bella Unión, Salto, Paysandú, and Fray Bentos. Each sample was concentrated by ultracentrifugation method. Qualitative and quantitative RT-PCR for RVA, NoV, and HAstV were performed. A wide dissemination of gastroenteric viruses was observed in the sewage samples analyzed with 80% of positivity, being NoV (51%) the most frequently detected followed by RVA with a frequency of 49% and HAstV with 45%. Genotypes of RVA were typed using multiplex semi-nested RT-PCR as follows: P[8] (n = 15), P[4] (n = 8), P[10] (n = 1), P[11] (n = 1), G2 (n = 29), and G3 (n = 2). The viral load ranged from 10(3) to 10(7) genomic copies/liter, and they were detected roughly with the same frequency in all participant cities. A peak of RVA and HAstV detection was observed in colder months (June to September), whereas no seasonality was observed for NoV. This study demonstrates for the first time, the high degree of gastroenteric viral contamination in the country; highlighting the importance of developing these analyses as a tool to determine the viral contamination in this hydrographic boundary region used by the local populations for recreation and consumption, establishing an elevated risk of gastroenteric diseases for human health.

High frequency of cultivable human subgroup F adenoviruses in stool samples from a paediatric population admitted to hospital with acute gastroenteritis

The family Adenoviridae consists of five genera of which the genus Mastadenovirus includes human viruses classified into 57 serotypes clustered into seven subgroups (A–G). Serotypes 40 and 41 (subgroup F) are specifically associated with childhood gastroenteritis and are the most common cause of acute gastroenteritis in young children after rotaviruses and noroviruses. Standard methods for laboratory diagnosis of adenovirus infection include electron microscopy (EM) and conventional cell culture (CCC), although it is widely considered that adenoviruses 40 and 41 are difficult to cultivate, such that their circulation is most likely underestimated. One hundred and ten faecal specimens from paediatric patients with gastroenteritis were confirmed positive for adenovirus by EM and/or CCC at the Virology Unit of the University Hospital of Parma, Italy, during the period January 2010–December 2012. They were analysed to determine the actual prevalence of adenovirus 40 and 41 in these patients using PCR and restriction endonuclease analysis, and to evaluate their ability to be cultivated in standard cell lines. The results showed a high prevalence of subgroup F (62.7 %), with serotype 41 (89.8 %) predominating over serotype 40 (10.2 %). Surprisingly, among the 75 adenoviruses isolated by CCC, 37 (49 %) belonged to subgroup F, suggesting a higher capacity of adenovirus 40 and 41 to replicate in cell culture than previously thought. PCR and restriction enzyme techniques provide an efficient means of diagnosing enteric adenoviruses correctly, including subgroup F adenovirus strains in young children with gastroenteritis.

Analysis of early strains of the norovirus pandemic variant GII.4 Sydney 2012 identifies mutations in adaptive sites of the capsid protein

Global surveillance for norovirus identified in 2012 the emergence of a novel pandemic GII.4 variant, termed Sydney 2012. In Italy, the novel pandemic variant was identified as early as November 2011 but became predominant only in the winter season 2012-2013. Upon sequencing and comparison with strains of global origin, the early Sydney 2012 strains were found to differ from those spreading in 2012-2013 in the capsid (ORF2) putative epitopes B, C and D, segregating into a distinct phylogenetic clade. At least three residues (333, 340 and 393, in epitopes B, C and D, respectively) of the VP1 varied among Sydney 2012 strains of different clades. These findings suggest that the spread of the pandemic variant in Italy during the winter season 2012-2013 was due to the introduction of strains distinct from those circulating at low frequency in the former winter season and that similar strains were also circulating elsewhere worldwide.

Human caliciviruses detected in HIV-seropositive children in Kenya

The human caliciviruses (HuCVs) are important causes of gastroenteritis worldwide. Norovirus (NoV) and sapovirus (SaV) have been detected in HIV-seropositive children but the genetic diversity of HuCVs circulating in these individuals is largely unknown. In this study the prevalence and genotype diversity of HuCVs circulating in Kenyan HIV-positive children, with or without diarrhea, from the year 1999 to 2000 was investigated. The overall prevalence of HuCVs was 19% with NoV predominating at 17% (18/105) and SaV present in 5.7% (6/105) of specimens. Human CVs were detected in both symptomatic (24%) and asymptomatic (16%) children. Co-infections with other enteric viruses were detected in 21.6% of children with diarrhea but only in 4.4% of children without diarrhea. Remarkable genetic diversity was observed with 12 genotypes (7 NoV, 5 SaV) being identified in 20 HuCV-infected children. NoV genogroup II (GII) strains predominated with GII.2 and GII.4 each representing 27% of the NoV-positive strains. The GII.4 strain was most closely related to the nonepidemic GII.4 Kaiso 2003 variant. Other NoV genotypes detected were GI.3, GII.6, GII.12, GII.14, and GII.17. Five different SaV genotypes (GI.2, GI.6, GII.1, GII.2, and GII.4) were characterized from six specimens. Diarrheal symptoms were not associated with any specific HuCV genotype. Overall the HuCV genotype distribution detected in this study reflects those in other studies worldwide. The strains detected are closely related to genotypes that have circulated on several continents since the year 2000.

Lineage diversification and recombination in type-4 human astroviruses

Human astroviruses (HAstVs) are important enteric pathogens and can be classified genetically and antigenically into eight types. During surveillance of HAstVs in Italy, type-4 HAstVs were detected only sporadically and found to cluster into two distinct genetic groups. Upon sequence analysis of the 3' end of the polymerase gene (ORF1b) and of the full-length ORF2, the 2008 type-4 HAstV strains were characterised as a novel ORF2 genetic lineage, designated as 4c. The 2008 type-4 HAstVs also shared the ORF1b gene with similar HAstV-4c strains detected globally, thus displaying a conserved ORF1b/ORF2 asset. By interrogation of the databases, this novel lineage 4c accounted for 60.8% of the type-4 strains identified worldwide and the vast majority of recent type-4 HAstVs. The 2002 type-4 HAstVs displayed a type-4b ORF2, whereas in the ORF1b they resembled type-1 HAstVs. This inconsistency suggests a possible recombinant origin, with the RNA switch taking place upstream the ORF1b/ORF2 junction region. Also, recombination likely played a role in the diversification of the ORF2 of the three type-4 lineages. Multi-target analysis is required for appropriate characterisation and identification of recombinant HAstVs.

Molecular detection of gastrointestinal viral infections in hospitalized patients

Gastrointestinal viral syndromes are a common cause of morbidity and mortality in humans worldwide. Etiological agents include a large number of viruses encompassing several orders, families, and genera. During the period April 2011 to April 2012, 689 stool samples from as many patients hospitalized at the Fondazione IRCCS Policlinico San Matteo of Pavia exhibiting gastrointestinal syndromes were examined for the presence of rotavirus, norovirus, astrovirus, adenovirus, rhinovirus, enterovirus, parechovirus, bocavirus, coronavirus, sapovirus, cosavirus, and aichi virus using polymerase chain reaction assays. Gastrointestinal viral agents were detected in 246 (36%) patients of the 689 analyzed. Adenovirus and norovirus were the most common viruses in this cohort, while aichi virus was the only gastrointestinal agent not detected. Surprisingly, rhinovirus was one of the most frequently detected viruses. However, a potential association with gastroenteritis remains to be confirmed.

Identification and Genotyping of Human Sapoviruses Collected from Sewage Water in Naples and Palermo, Italy, in 2011

Human sapoviruses were identified in 15 (12.4 %) of 121 inlet sewage samples collected from wastewater treatment plants in Naples and Palermo, Italy, in 2011. All strains, except one GI.1, were genotyped as GI.2 by sequencing a capsid gene fragment. This is the first detection of sapovirus in wastewaters in Italy.

Evidence for recombination between pandemic GII.4 norovirus strains New Orleans 2009 and Sydney 2012

During 2012, a novel pandemic GII.4 norovirus variant, Sydney 2012, emerged worldwide. A signature of the variant was a GII.Pe ORF1, in association with GII.4 Apeldoorn 2008-like ORF2-ORF3 genes. We report the detection of recombinant GII.4 Sydney 2012 strains, possessing the ORF1 gene of the former pandemic variant New Orleans 2009.