Enteric Viral Pathogens Research Articles

Seasonal distribution of febrile seizure and the relationship with respiratory and enteric viruses in Korean children based on nationwide registry data

PurposeThe seasonal distribution patterns of febrile seizures and of respiratory and enteric viral pathogens are similar. In this study, we analyzed trends in febrile seizures and viral infection in Korean children, using big data from the Korean Health Insurance Review and Assessment Service (HIRA). MethodsWe analyzed children younger than 6 years who visited the hospital and were diagnosed with febrile seizures from 2009 to 2016, using medical records in the HIRA database. A total of 666,136 medical records of children with a main or subdiagnosis of febrile seizure from 2008 to 2016 were included. Of these records, patients younger than 1 month and records before 2009 were excluded. Finally, 558,130 records were extracted. ResultsThe medical records included 315,774 male children and 242,356 (43.4%) female children, with a mean age of 2.31 ± 1.31 years. The annual incidence of febrile seizure was 25.4 per 1000 person-years (27.9 for boys and 22.7 for girls). The ratio of male to female children was 1.30: 1, and records of 1-year-old children comprised the highest proportion (n = 210,400, 33.70%). The total monthly number of patients was highest in May (n = 64,969, 11.6%), and peaks were formed from April to July. The fewest patients were seen in October (n = 34,424, 6.17%). The most common viral pathogens were influenza in April and enterovirus during May–July. ConclusionThe seasonal distribution of febrile seizures was high from late spring to summer, and influenza virus and enterovirus were most frequently associated.

Traveler's diarrhea in Nepal-changes in etiology and antimicrobial resistance.

We conducted a comprehensive investigation to update our knowledge of traveler's diarrhea (TD) etiology and antimicrobial resistance (AMR) in Nepal. A case-control study of TD etiology was conducted at the CIWEC Clinic Travel Medicine Center in Kathmandu from 2012 to 2014. Stool samples were tested by microscopy, culture and molecular techniques for identification of bacterial, viral and parasitic enteric pathogens, and AMR. We analysed patient demographic data, pre-treatment information and clinical outcomes. We enrolled 433 TD cases and 209 non-diarrhea controls. At least one of enteric pathogens was identified among 82% of cases and 44% of controls (P < 0.001). Multiple pathogens were observed among 35% of cases and 10% of controls. The most common pathogens significantly identified among cases in comparison with controls were Campylobacter (20%), norovirus (17%), enterotoxigenic E. coli (ETEC) (12%), rotavirus (9%) and Shigella (8%) (P < 0.001). We noted Campylobacter, Shigella and ETEC resistance to azithromycin at 8, 39 and 22% and to ciprofloxacin at 97, 78 and 23%, respectively. Among travellers to Nepal with TD, viral pathogens were commonly found and norovirus was the second most common pathogen after campylobacter. We noted increased AMR to fluoroquinolones (FQs) and azithromycin (AZM). There is heightened concern for AZM treatment failures, though this continues to remain the drug of choice for TD treatment in our setting where FQs should not be used.

Engineering a Live Attenuated Porcine Epidemic Diarrhea Virus Vaccine Candidate via Inactivation of the Viral 2'-O-Methyltransferase and the Endocytosis Signal of the Spike Protein.

Porcine epidemic diarrhea virus (PEDV) causes high mortality in neonatal piglets; however, effective and safe vaccines are still not available. We hypothesized that inactivation of the 2'-O-methyltransferase (2'-O-MTase) activity of nsp16 and the endocytosis signal of the spike protein attenuates PEDV yet retains its immunogenicity in pigs. We generated a recombinant PEDV, KDKE4A, with quadruple alanine substitutions in the catalytic tetrad of the 2'-O-MTase using a virulent infectious cDNA clone, icPC22A, as the backbone. Next, we constructed another mutant, KDKE4A-SYA, by abolishing the endocytosis signal of the spike protein of KDKE4A Compared with icPC22A, the KDKE4A and KDKE4A-SYA mutants replicated less efficiently in vitro but induced stronger type I and type III interferon responses. The pathogenesis and immunogenicities of the mutants were evaluated in gnotobiotic piglets. The virulence of KDKE4A-SYA and KDKE4A was significantly reduced compared with that of icPC22A. Mortality rates were 100%, 17%, and 0% in the icPC22A-, KDKE4A-, and KDKE4A-SYA-inoculated groups, respectively. At 21 days postinoculation (dpi), all surviving pigs were challenged orally with a high dose of icPC22A. The KDKE4A-SYA- and KDKE4A-inoculated pigs were protected from the challenge, because no KDKE4A-SYA- and one KDKE4A-inoculated pig developed diarrhea whereas all the pigs in the mock-inoculated group had severe diarrhea, and 33% of them died. Furthermore, we serially passaged the KDKE4A-SYA mutant in pigs three times and did not find any reversion of the introduced mutations. The data suggest that KDKE4A-SYA may be a PEDV vaccine candidate.IMPORTANCE PEDV is the most economically important porcine enteric viral pathogen and has caused immense economic losses in the pork industries in many countries. Effective and safe vaccines are desperately required but still not available. 2'-O-MTase (nsp16) is highly conserved among coronaviruses (CoVs), and the inactivation of nsp16 in live attenuated vaccines has been attempted for several betacoronaviruses. We show that inactivation of both 2'-O-MTase and the endocytosis signal of the spike protein is an approach to designing a promising live attenuated vaccine for PEDV. The in vivo passaging data also validated the stability of the KDKE4A-SYA mutant. KDKE4A-SYA warrants further evaluation in sows and their piglets and may be used as a platform for further optimization. Our findings further confirmed that nsp16 can be a universal target for CoV vaccine development and will aid in the development of vaccines against other emerging CoVs.

Capsid Integrity qPCR—An Azo-Dye Based and Culture-Independent Approach to Estimate Adenovirus Infectivity after Disinfection and in the Aquatic Environment

Recreational, reclaimed and drinking source waters worldwide are under increasing anthropogenic pressure, and often contain waterborne enteric bacterial, protozoan, and viral pathogens originating from non-point source fecal contamination. Recently, the capsid integrity (ci)-qPCR, utilizing the azo-dyes propidium monoazide (PMA) or ethidium monoazide (EMA), has been shown to reduce false-positive signals under laboratory conditions as well as in food safety applications, thus improving the qPCR estimation of virions of public health significance. The compatibility of two widely used human adenovirus (HAdV) qPCR protocols was evaluated with the addition of a PMA/EMA pretreatment using a range of spiked and environmental samples. Stock suspensions of HAdV were inactivated using heat, UV, and chlorine before being quantified by cell culture, qPCR, and ci-qPCR. Apparent inactivation of virions was detected for heat and chlorine treated HAdV while there was no significant difference between ci-qPCR and qPCR protocols after disinfection by UV. In a follow-up comparative analysis under more complex matrix conditions, 51 surface and 24 wastewater samples pre/post UV treatment were assessed for enteric waterborne HAdV to evaluate the ability of ci-qPCR to reduce the number of false-positive results when compared to conventional qPCR and cell culture. Azo-dye pretreatment of non-UV inactivated samples was shown to improve the ability of molecular HAdV quantification by reducing signals from virions with an accessible genome, thereby increasing the relevance of qPCR results for public health purposes, particularly suited to resource-limited low and middle-income settings.

The Relationship Between Human Adenovirus and Metals and Semimetals in the Waters of the Rio Doce, Brazil.

The 2015 rupture of the Fundão dam near the district of Bento Rodrigues in Mariana, Minas Gerais, Brazil, released around 50 million m3 of iron ore tailings. The first tributary of the Rio Doceto receive this waste was the Gualaxo do Norte River. Many groups in Brazil and from around the world have studied the environmental and social impacts of this disaster. However, relationships between the introduction of mining waste, the geological complexity of the area, and the presence of pathogenic organisms have not yet been investigated. The present study aimed to measure the concentrations of enteric pathogens along the Gualaxo do Norte River after the environmental disaster and to correlate their abundance with the presence of metals and semimetals coming from both mining tailings and geological sources. For this purpose, we collected water samples from 27 stations along the entire basin during a hydrological year. The concentrations of metals and semimetals measured in this study were generally within limits established by national and international legislation, except for those of iron and manganese. Positive correlations between the human adenovirus (HAdV) and arsenic, barium, iron, lead, manganese, and nickel were confirmed, allowing us to observe that there is an abundance of the potentially infectious virus present in the studied sites containing metal/semimetal concentrations. These studies indicate the importance of investigations that consider viral enteric pathogens complexed with metals and may favor the stability and prolongation of the infectivity of such pathogens in water destined for human and animal usage.

Performance evaluation of gastrointestinal viral ELIte panel multiplex RT-PCR assay for the diagnosis of rotavirus, adenovirus and astrovirus infection

Rotavirus, adenovirus, norovirus and astrovirus are considered to be among the major causes of sporadic cases and outbreaks of acute gastroenteritis globally. Rapid and accurate identification of enteric viruses is still a challenge for the clinical laboratory. Recently, several molecular platforms for the detection of viral enteric pathogens have become available. In this study, the diagnostic accuracy of InGenius Gastrointestinal Viral (GV) Elite Panel, a newly developed one-step multiplex real-time RT-PCR assay simultaneously detecting rotavirus, adenovirus and astrovirus, was evaluated retrospectively analyzing an archival collection of 128 stool samples of children hospitalized with acute gastroenteritis. The overall sensitivity and specificity for the GV assay was 100% and 96.2% for rotavirus, 96.9% and 100% for astrovirus, 100% and 100% for adenovirus, respectively. The InGenius GV assay showed a high concordance with the reference methods and was able to detect all tested genotypes of rotavirus (including G1, G3, G4, G9 and G12P[8] and G2P[4]), adenovirus and astrovirus (AstV-1 and 2). Studies of considerable sample size are required to determine robust Cycle threshold cut-off values to effectively correlate infection to disease. These preliminary results suggest that InGenius GV assay can be recommended as a valuable method for accurate diagnosis of epidemic and sporadic gastroenteritis.

Coinfection of diarrheagenic bacterial and viral pathogens in piglets of Northeast region of India.

Aim:This study aimed to study the prevalence of the coinfection of enteric bacterial and viral pathogens, namely Escherichia coli, Salmonella, Rotavirus, and Picobirnavirus from fecal samples of pre-weaned piglets in Northeast region of India.Materials and Methods:A total of 457 fresh fecal samples were collected from piglets under 9 weeks old during 2013-2015 from organized (n=225) and unorganized (n=232) farms of Manipur, Meghalaya, Mizoram, and Nagaland. Samples were collected from diarrheic (n =339) and non-diarrheic (n=118) piglets including local indigenous (n=130) and crossbreed (n=327) piglets in different seasons during the study period. The samples were processed for the isolation of E. coli and Salmonella and detection of their putative virulence genes by polymerase chain reaction (PCR). Samples were also processed for the detection of Rotavirus and Picobirnavirus by RNA-polyacrylamide agarose gel electrophoresis and reverse transcriptase-PCR (RT-PCR).Results:A total of 11 (2.40%) samples were found positive for two or more coinfecting enteric bacterial and viral pathogens. All the 11 positive fecal samples were recovered from diarrheic piglets. Salmonella Typhimurium (enterotoxin, stn gene) and Picobirnavirus genogroup 1 were found to be more frequent as coinfecting agents. Coinfection was recorded higher in unorganized (3.87%) compared to organized farm (0.88%). Again, higher detection was recorded in crossbreed (2.75%) than local indigenous piglets (1.53%). The occurrence of coinfection was found to be more common during summer (4.68%) followed by winter (2.27%) season.Conclusion:The present study highlighted the significance of E. coli, Salmonella, Rotavirus, and Picobirnavirus as important diarrheagenic pathogens causing coinfection in piglets in Northeast region of India. Probably, this is the first systematic study of the coinfection of four important diarrheagenic bacterial and viral agents associated with piglet diarrhea in India.

Gut Virome Analysis of Cameroonians Reveals High Diversity of Enteric Viruses, Including Potential Interspecies Transmitted Viruses.

Diarrhea remains one of the most common causes of deaths in children. A limited number of studies have investigated the prevalence of enteric pathogens in Cameroon, and as in many other African countries, the cause of many diarrheal episodes remains unexplained. A proportion of these unknown cases of diarrhea are likely caused by yet-unidentified viral agents, some of which could be the result of (recent) interspecies transmission from animal reservoirs, like bats. Using viral metagenomics, we screened fecal samples of 221 humans (almost all with gastroenteritis symptoms) between 0 and 89 years of age with different degrees of bat contact. We identified viruses belonging to families that are known to cause gastroenteritis such as Adenoviridae, Astroviridae, Caliciviridae, Picornaviridae, and Reoviridae Interestingly, a mammalian orthoreovirus, picobirnaviruses, a smacovirus, and a pecovirus were also found. Although there was no evidence of interspecies transmission of the most common human gastroenteritis-related viruses (Astroviridae, Caliciviridae, and Reoviridae), the phylogenies of the identified orthoreovirus, picobirnavirus, and smacovirus indicate a genetic relatedness of these viruses identified in stools of humans and those of bats and/or other animals. These findings points out the possibility of interspecies transmission or simply a shared host of these viruses (bacterial, fungal, parasitic, …) present in both animals (bats) and humans. Further screening of bat viruses in humans or vice versa will elucidate the epidemiological potential threats of animal viruses to human health. Furthermore, this study showed a huge diversity of highly divergent novel phages, thereby expanding the existing phageome considerably.IMPORTANCE Despite the availability of diagnostic tools for different enteric viral pathogens, a large fraction of human cases of gastroenteritis remains unexplained. This could be due to pathogens not tested for or novel divergent viruses of potential animal origin. Fecal virome analyses of Cameroonians showed a very diverse group of viruses, some of which are genetically related to those identified in animals. This is the first attempt to describe the gut virome of humans from Cameroon. Therefore, the data represent a baseline for future studies on enteric viral pathogens in this area and contribute to our knowledge of the world's virome. The studies also highlight the fact that more viruses may be associated with diarrhea than the typical known ones. Hence, it provides meaningful epidemiological information on diarrhea-related viruses in this area.

Genetic diversity of human parechoviruses in stool samples, Germany

Human parechoviruses (HPeV) are ubiquitous and mainly occur in early infancy. They are known to cause various clinical manifestations including acute gastroenteritis. To gain insight into the diversity of circulating HPeV genotypes, stool samples from patients (n = 539) with clinical signs of infectious gastroenteritis which showed negative results for other common viral and bacterial enteric pathogens were obtained during three years, 2008 to 2010. Real-time RT-PCR showed HPeV RNA in 34 (6.3%) of the samples. The HPeV detection rate was highest (8.8%) in samples derived from infants and young children under the age of two years. Genotyping was based on VP3/VP1 junction nucleic acid sequences and revealed predominant HPeV-1B (n = 16) and HPeV-3 (n = 12) strains. Those prevailed minor HPeV-6 (n = 3) as well as HPeV-2, −4 and −5 (n = 1, each) strains. To ascertain the assigned HPeV-2 genotype of uncommon strain LPZ04-2008, analysis of complete coding sequences was performed. In complete VP1 analysis strain LPZ04-2008 showed 81.2% nucleic acid identity with HPeV-2 reference strain Williamson. In phylogenetic analysis VP1 of strain LPZ04–2008 clustered with a recent HPeV-2 strain from the UK. Regarding clinical manifestations, severe disease occurred HPeV-1B, −3 and − 6 infections. In conclusion, this paper a high genetic diversity of HPeV in stool samples, including rare strains. The investigation adds data on the whole coding sequences of the rare HPeV-2 strain. Genotyping results confirm previously reported association of more severe illness with HPeV-3 and HPeV-1B strains.

694. The CAGE Study: Prevalence of Acute Gastroenteritis and Enteric Virus Infection in the Community

BackgroundThere are currently limited data about the occurrence and characteristics of sporadic acute gastroenteritis (AGE). In this study, we sought to (1) estimate the average point prevalence of AGE over a 1-year period; (2) describe health-seeking behaviors among those with AGE; and (3) calculate the proportion of stool samples testing positive for enteric viral pathogens.MethodsStarting in October 2016, we recruited 52 weekly, age-stratified, random samples of Kaiser Permanente Northwest members to complete an online survey and, for a subset of participants, to submit a stool specimen. The survey included questions about the occurrence of vomiting and/or diarrhea within the previous 30 days and, for those reporting AGE symptoms, related health-seeking behaviors. Collected stool samples were tested for norovirus, astrovirus, sapovirus, and rotavirus by RT-qPCR.ResultsWe received a total of 3,483 surveys from eligible participants, 417 (12%) of whom reported having had AGE symptoms (Figure 1). Of these, 70 (17%) sought related medical care across a spectrum of clinical encounter types (Figure 2). We also received a total of 531 stool samples, 74 from symptomatic and 457 from asymptomatic individuals. Among them, we detected norovirus in 12% and 3% of samples (P = 0.0005), respectively; astrovirus and sapovirus in 1% of samples in each group; and rotavirus in 8% and 7% of samples, respectively.ConclusionOur findings of AGE within the community are consistent with previous estimates using models of medically attended AGE occurrence and reported rates of health-seeking behavior. The prevalence of enteric viral infection among people in the community without AGE was generally low. These data can be used to generate age-stratified incidence estimates of community AGE and specifically that associated with enteric viral pathogens. Such disease burden data are needed to guide the development, targeting, and anticipated impacts of interventions, such as vaccines. Disclosures M. A. Schmidt, Takeda Vaccines, Inc.: Investigator, Research grant. S. B. Salas, Takeda Vaccines, Inc.: Investigator, Research grant. H. Groom, Takeda Vaccines, Inc.: Investigator, Research grant. G. Rosales, Takeda Vaccines, Inc.: Investigator, Research grant. J. Donald, Takeda Vaccines, Inc.: Investigator, Research grant. A. Naleway, Takeda Vaccines, Inc.: Investigator, Research grant.

Open Defecation Sites, Unmet Sanitation Needs, and Potential Sanitary Risks in Atlanta, Georgia, 2017-2018.

To survey the spatial distribution and enteric pathogen profile of discarded human feces in the city of Atlanta, Georgia. After defining priority search areas in central Atlanta, we conducted 5 searches of open defecation sites totaling 15 hours during the period from October 2017 to January 2018. We collected fresh stools for analysis via multiplex reverse-transcription polymerase chain reaction to identify presence of 15 common parasitic, bacterial, and viral enteric pathogens. We identified and mapped 39 open defecation sites containing 118 presumptive human stools; 23% of the 26 collected fresh stools tested positive for 1 or more pathogens. An estimated 12% of stools were positive for enterotoxigenic Escherichia coli, 7.7% for Giardia spp., 3.8% for norovirus, and 3.8% for Salmonella spp. The majority (92%) of identified open defecation sites were within 400 meters of a shelter or soup kitchen. Though this study was constrained by a small sample size, results suggest that open defecation in Atlanta is common and may pose risks to public health. Public Health Implications. Open defecation may pose health risks to people experiencing homelessness and the general public.

Incidence of somatic and F+ coliphage in Great Lake Basin recreational waters

There is a growing interest for the use of coliphage as an alternative indicator to assess fecal pollution in recreational waters. Coliphage are a group of viruses that infect Escherichia coli and are considered as potential surrogates to infer the likely presence of enteric viral pathogens. We report the use of a dead-end hollow fiber ultrafiltration single agar layer method to enumerate F+ and somatic coliphage from surface waters collected from three Great Lake areas. At each location, three sites (two beaches; one river) were sampled five days a week over the 2015 beach season (n = 609 total samples). In addition, culturable E. coli and enterococci concentrations, as well as 16 water quality and recreational area parameters were assessed such as rainfall, turbidity, dissolved oxygen, pH, and ultra violet absorbance. Overall, somatic coliphage levels ranged from non-detectable to 4.39 log10 plaque forming units per liter and were consistently higher compared to F+ (non-detectable to 3.15 log10 PFU/L), regardless of sampling site. Coliphage concentrations weakly correlated with cultivated fecal indicator bacteria levels (E. coli and enterococci) at 75% of beach sites tested in study (r = 0.28 to 0.40). In addition, ultraviolet light absorption and water temperature were closely associated with coliphage concentrations, but not fecal indicator bacteria levels suggesting different persistence trends in Great Lake waters between indicator types (bacteria versus virus). Finally, implications for coliphage water quality management and future research directions are discussed.

Detection of enteric- and non-enteric adenoviruses in gastroenteritis patients, Bangladesh, 2012-2015.

Human adenoviruses (HAdVs) are common cause of nonbacterial acute gastroenteritis worldwide. Limited data exist on HAdVs molecular epidemiology associated with acute gastroenteritis in Bangladesh. We describe the genetic diversity and epidemiology of HAdVs among hospitalized diarrhea patients, including HAdV genotypes, clinical symptoms, and co-infecting enteric pathogens. Stool samples were collected from ongoing diarrhea surveillance during 2012-2015. HAdV was detected using PCR and genotyped by sequencing and phylogenetic analysis. Detailed socio-demographic and clinical information regarding each individual was recorded such as duration of diarrhea, dehydration status, vomiting, abdominal pain, fever, and severity. Of 871 fecal specimens, HAdV DNA was detected in 93 (10.7%). Among them 56% were co-infected with other known enteric viral and bacterial pathogens and 31.6% had severe gastroenteritis. The majority (55%) of HAdV positives were children <5 years of age. Two main clinical symptoms in HAdV infected patients were diarrhea and vomiting. HAdVs were detected throughout the year with low prevalence in winter (November-January). Five HAdV species (A, B, C, D, and F) including 17 different genotypes were identified during the study period, with enteric HAdV species F (HAdV-40/41) being the most dominant. However, non-enteric HAdV were also detected in substantial proportion of specimens (15% species C, 15% species D, 10.8% species A, and 4.3% species B). Our study demonstrates high genetic diversity of HAdVs including enteric and non-enteric HAdVs among diarrhea patients and provides a foundation for further clarification of the role of non-enteric HAdVs in diarrheal diseases.

VAetiology of Diarrhoea in Children Under Five in Zambia Detected Using Luminex xTAG Gastrointestinal Pathogen Panel

Background: We aimed to document viral, bacterial, and protozoan enteric pathogens responsible of causing moderate-to-severe diarrhoea among children under five presenting at public health facilities in Zambia following the introduction of rotavirus vaccination. Methods: This was a cross-sectional study in which clinical data and stool samples were collected between July 2012 and October 2013 from children under five years presenting to outpatient clinics in Lusaka province with moderate-tosevere diarrhoea. The study was conducted during the early months post rotavirus vaccine introduction in Zambia. We used Luminex x-TAG® gastrointestinal pathogen panel to simultaneously detect enteric viruses, bacteria and protozoa from the stool samples. We applied the population attributable fraction to estimate pathogen-specific burden of moderate-to-severe diarrhoea. Results: We analysed 1,135 unique stool samples with clinical data, of which 56% had received one or full dose rotavirus vaccination. The median age was 14 months (IQR=8, 22). The prevalence of moderate-to-severe diarrhoea was estimated as 18.9% (95%CI=16.7, 21.2). The most attributable cases of moderate-to-severe diarrhoea were due to rotavirus {attributable fraction=24.5%; 95%CI=(5.4, 39.7)} followed by Shigella spp. {attributable fraction=6.7%; 95%CI=(0.1, 15.5)}. The top 5 enteric pathogens detected among children were rotavirus (67.6%), Adenovirus (41.5%), ETEC (40.7%), Salmonella (38.4%) and Giardia (37.0%). Conclusion: We found that about one-third of moderate-to-severe diarrhoea among children were attributable to rotavirus and shigella spp.

High Frequency of Enteric Protozoan, Viral, and Bacterial Potential Pathogens in Community-Acquired Acute Diarrheal Episodes: Evidence Based on Results of Luminex Gastrointestinal Pathogen Panel Assay.

Infectious diarrhea is endemic in most developing countries. We aimed to investigate the protozoan, viral, and bacterial causes of acute diarrhea in Taif, Saudi Arabia. A cross-sectional prospective 1-year study was conducted on 163 diarrheal patients of various ages. Stool samples were collected, 1 per patient, and tested for 3 protozoa, 3 viruses, and 9 bacteria with the Luminex Gastrointestinal Pathogen Panel. Overall, 53.4% (87/163) of samples were positives (20.8% protozoa, 19.6% viruses, 2.8% bacteria, and 9.8% mixed). Rotavirus (19.6%), Giardia duodenalis (16.5%), and Cryptosporidium spp. (8.5%) were the mostly detected pathogens. Adenovirus 40/41 (4.2%), Salmonella (3%), Shiga toxin-producing Escherichia coli (3%), and Entamoeba histolytica (2.4%) were also detected. Norovirus GI/II, Vibrio cholerae, Yersinia enterocolitica, and Clostridium difficile toxin A/B were not detected in any patients. All pathogens were involved in coinfections except E. histolytica. Giardia (5.5%) and rotavirus (3%) were the most commonly detected in co-infections. Enterotoxigenic E. coli (2.4%), Campylobacter spp. (2.4%), E. coli 0157 (1.8%), and Shigella spp. (1.2%) were detected in patients only as co-infections. Infections were more in children 0–4 years, less in adults <40 years, and least >40 years, with statistically significant differences in risk across age groups observed with rotavirus (P<0.001), Giardia (P=0.006), and Cryptosporidium (P=0.036) infections. Lastly, infections were not significantly more in the spring. This report demonstrates the high burden of various enteropathogens in the setting. Further studies are needed to define the impact of these findings on the clinical course of the disease.

Comparison of three multiplex gastrointestinal platforms for the detection of gastroenteritis viruses

BackgroundViruses are major etiological agents of childhood gastroenteritis. In recent years, several molecular platforms for the detection of viral enteric pathogens have become available. Objective/study designWe evaluated the performance of three multiplex platforms including Biofire’s Gastrointestinal Panel (FilmArray), Luminex xTAG® Gastrointestinal Pathogen Panel (GPP), and the TaqMan Array Card (TAC) for the detection of five gastroenteritis viruses using a coded panel of 300 archived stool samples. ResultsThe FilmArray detected a virus in 199 (96.1%) and the TAC in 172 (83.1%) of the 207 samples (187 samples positive for a single virus and 20 samples positive for more than one virus) whereas the GPP detected a virus in 100 (78.7%) of the 127 (97 positive for one virus and three positive for more than one virus) samples. Overall the clinical accuracy was highest for the FilmArray (98%) followed by TAC (97.2%) and GPP (96.9%). The sensitivity of the FilmArray, GPP and TAC platforms was highest for rotavirus (100%, 95.8%, and 89.6%, respectively) and lowest for adenovirus type 40/41 (97.4%, 57.9% and 68.4%). The specificity of the three platforms ranged from 95.6% (rotavirus) to 99.6% (norovirus/sapovirus) for the FilmArray, 99.6% (norovirus) to 100% (rotavirus/adenovirus) for GPP, and 98.9% (astrovirus) to 100% (rotavirus/sapovirus) for TAC. ConclusionThe FilmArray demonstrated the best analytical performance followed by TAC. In recent years, the availability of multi-enteric molecular testing platforms has increased significantly and our data highlight the strengths and weaknesses of these platforms.

Expression of Ifnlr1 on Intestinal Epithelial Cells Is Critical to the Antiviral Effects of Interferon Lambda against Norovirus and Reovirus.

Lambda interferon (IFN-λ) has potent antiviral effects against multiple enteric viral pathogens, including norovirus and rotavirus, in both preventing and curing infection. Because the intestine includes a diverse array of cell types, however, the cell(s) upon which IFN-λ acts to exert its antiviral effects is unclear. Here, we sought to identify IFN-λ-responsive cells by generation of mice with lineage-specific deletion of the receptor for IFN-λ, Ifnlr1 We found that expression of IFNLR1 on intestinal epithelial cells (IECs) in the small intestine and colon is required for enteric IFN-λ antiviral activity. IEC Ifnlr1 expression also determines the efficacy of IFN-λ in resolving persistent murine norovirus (MNoV) infection and regulates fecal shedding and viral titers in tissue. Thus, the expression of Ifnlr1 by IECs is necessary for the response to both endogenous and exogenous IFN-λ. We further demonstrate that IEC Ifnlr1 expression is required for the sterilizing innate immune effects of IFN-λ by extending these findings in Rag1-deficient mice. Finally, we assessed whether our findings pertained to multiple viral pathogens by infecting mice specifically lacking IEC Ifnlr1 expression with reovirus. These mice phenocopied Ifnlr1-null animals, exhibiting increased intestinal tissue titers and enhanced reovirus fecal shedding. Thus, IECs are the critical cell type responding to IFN-λ to control multiple enteric viruses. This is the first genetic evidence that supports an essential role for IECs in IFN-λ-mediated control of enteric viral infection, and these findings provide insight into the mechanism of IFN-λ-mediated antiviral activity.IMPORTANCE Human noroviruses (HNoVs) are the leading cause of epidemic gastroenteritis worldwide. Type III interferons (IFN-λ) control enteric viral infections in the gut and have been shown to cure mouse norovirus, a small-animal model for HNoVs. Using a genetic approach with conditional knockout mice, we identified IECs as the dominant IFN-λ-responsive cells in control of enteric virus infection in vivo Upon murine norovirus or reovirus infection, Ifnlr1 depletion in IECs largely recapitulated the phenotype seen in Ifnlr1-/- mice of higher intestinal tissue viral titers and increased viral shedding in the stool. Moreover, IFN-λ-mediated sterilizing immunity against murine norovirus requires the capacity of IECs to respond to IFN-λ. These findings clarify the mechanism of action of this cytokine and emphasize the therapeutic potential of IFN-λ for treating mucosal viral infections.

THE BURDEN AND FUTURE SCOPE FOR IMPORTANT VIRAL ENTERIC PATHOGENS IN AFRICA

BackgroundThe burden of viral enteric infections in Africa is enormous, although poorly described. Some, such as rotavirus, are well recognized, whereas others including norovirus or enteric adenovirus (EAd), show high...

Epidemiological survey of enteric viruses in wild boars in the Czech Republic: First evidence of close relationship between wild boar and human rotavirus A strains

Population of wild boar is increasing in the whole Europe, the animals migrate close to human habitats which greatly increases the possibility of natural transmission between domestic animals or humans and wild boars. The aim of the study was to estimate in population of free-living wild boar in the Czech Republic the prevalence of enteric viral pathogens, namely rotavirus groups A and C (RVA and RVC), porcine reproductive and respiratory syndrome virus (PRRSV), and members of family Coronaviridae (transmissible gastroenteritis virus – TGEV, porcine epidemic diarrhea virus − PEDV, porcine respiratory coronavirus – PRCV, and porcine hemagglutination encephalomyelitis virus – PHEV) and Picornaviridae,(teschovirus A – PTV, sapelovirus A – PSV, and enterovirus G – EV-G). In our study, stool samples from 203 wild boars culled during hunting season 2014–2015 (from October to January) were examined by RT-PCR. RVA was detected in 2.5% of tested samples. Nucleotide analysis of VP7, VP4, and VP6 genes revealed that four RVA strains belong to G4P[25]I1, G4P[6]I5, G11P[13]I5, and G5P[13]I5 genotypes and phylogenetic analysis suggested close relation to porcine and human RVAs. The prevalence of RVC in wild boar population reached 12.8%, PTV was detected in 20.2%, PSV in 8.9%, and EV-G in 2.5% of samples. During our study no PRRSV or coronaviruses were detected. Our study provides the first evidence of RVC prevalence in wild boars and indicates that wild boars might contribute to the genetic variability of RVA and also serve as an important reservoir of other enteric viruses.

Removal of phages and viral pathogens in a full-scale MBR: Implications for wastewater reuse and potable water

The aim of this study was to demonstrate how seasonal variability in the removal efficacy of enteric viral pathogens from an MBR-based water recycling system might affect risks to human health if the treated product were to be used for the augmentation of potable water supplies. Samples were taken over a twelve month period (March 2014–February 2015), from nine locations throughout a water recycling plant situated in East London and tested for faecal indicator bacteria (thermotolerant coliforms, intestinal enterococci n = 108), phages (somatic coliphage, F-specific RNA phage and Bacteroides phage (GB-124) n = 108), pathogenic viruses (adenovirus, hepatitis A, norovirus GI/GII n = 48) and a range of physico-chemical parameters (suspended solids, DO, BOD, COD). Thermotolerant coliforms and intestinal enterococci were removed effectively by the water recycling plant throughout the study period. Significant mean log reductions of 3.9–5.6 were also observed for all three phage groups monitored. Concentrations of bacteria and phages did not vary significantly according to season (P < 0.05; Kruskal-Wallis), though recorded levels of norovirus (GI) were significantly higher during autumn/winter months (P = 0.027; Kruskal-Wallis). Log reduction values for norovirus and adenovirus following MBR treatment were 2.3 and 4.4, respectively. However, both adenovirus and norovirus were detected at low levels (2000 and 3240 gene copies/L, respectively) post chlorination in single samples. Whilst phage concentrations did correlate with viral pathogens, the results of this study suggest that phages may not be suitable surrogates, as viral pathogen concentrations varied to a greater degree seasonally than did the phage indicators and were detected on a number of occasions on which phages were not detected (false negative sample results).