Viral and bacterial infections can present remarkably similar clinical symptoms in gastroenteritis. Most enteric viral infec- tions cause mild to moderate diarrhea (with the exception of rotavirus) (27). Though many severe cases of O157 STEC gastrointestinal infections, especially those of the O157:H7 serotype, yield bloody diarrhea (9, 14), most infections do not progress to this stage and therefore can sometimes be thought to have a viral etiology. This is further complicated by non- O157 STEC infections, which are not commonly associated with bloody stool and can often resemble viral gastroenteritis. Based on our provincial historical data, the season in which an enteric infection is identified can often predict whether the causative agent is viral or bacterial, as enteric viral infections are more frequently found during the winter months, whereas enteric bacterial infections are more prevalent from May to September. The overall ambiguity of non-O157 STEC infec- tions and viral gastroenteritis led us to screen stool samples that were referred for viral diagnostics between May and Sep- tember for the presence of STEC to better understand the extent of these potentially undiagnosed infections. The median age of patients for which enteric viruses were isolated was lower than the median age of those who had STEC infection in our study. However, a large proportion of STEC-positive stools were from children younger than 6 years (19/38), which is highly concerning as young children are at a higher risk for developing HUS (3).
random primers in the RT step and multiplex PCR assays for the panels of enteric viruses did not lower the efficiency or detection limits of most of the PCR assays. Only the PCR for RV had a lower efficiency. An explanation for this could be that RV is a double-stranded RNA virus for which denatur- ation requires more stringent conditions, resulting in less effi- cient annealing (10, 21). However, as the detection limits were not affected, we decided that this slight decrease in efficiency of the PCR for RV was acceptable. Remarkably, once the mul- tiplex PCR assays were implemented in the clinical setting, we found that more viruses causing acute viral gastroenteritis were detected by the multiplex PCR assays than by the previously used monoplex assays but with the same specificity, showing a clear improvement in the diagnostic yield (20). A possible explanation for this lies in the increased efficiency of cDNA production by the use of random primers. All the viruses tar- geted in these assays have a substantial degree of genetic variability. Given this diversity, the choice of primers for use for cDNA synthesis and PCR, by definition, requires a com- promise between the broadness of that assay and specificity. The original RT primers had several ambiguities to allow broad-range detection, which may have decreased the cDNA yield (3). The results presented above also show the impor- tance of validation of the assay with clinical samples, as the difference in yield was not expected on the basis of the results of the technical validation.
Background: Acute gastroenteritis (AGE) influences stomach and gut and is one of the important popular troubles in infants and young children throughout the world. The causes of acute gastritis include medications as well as viruses such as rotavirus and enteric adenovirus. Rotavirus accounts for the many illnesses and is the most prevalent cause of acute diarrhea and also severe gastroenteritis in KSA (Kingdom of Saudi Arabia). Aim: This study aimed to investigate the prevalence of using antibiotics for acute viral gastroenteritis in the pediatrics population in AlmadinahAlmunawrah. Method: This was a prospective, quantitative, cross- sectional survey consisting of thirty questions. Responded questionnaire from 600 pediatric physicians of children under 6 years of age suffering from acute gastroenteritis in AlmadinahAlmonawarah. Data sources: Face to face questions from physicians.Results: demographic distribution of our study’s data. 53.1% of patients were male. 54.5% of individuals were between 25-35 years. Family physicians and general physicians with 27.1% and 24.2%,respectivelywere the most constituents of the study specialty. Indications for treating acute viral gastroenteritis frequently. In 50.1% of individuals, the usage of antibiotics was to prevent secondary infection. From the viewpoint of the prevalence of the most common route preferred by the study individuals, oral and intravenous antibiotics were preferred by 51.9% and 28.7% of the participants, respectively. Treatment with antibiotics over a period of less than a week was prescribed in about 50.2% of the participants. Treatment over a period of 7-14 days was recorded by 39%. Summer was the most common season for viral infection endemics as stated by 64%. Winter was stated as the second most common season by 29.7%. Family physicians and general practitioners
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Acute viral gastroenteritis is an important and often un- appreciated cause of morbidity and mortality worldwide. Nearly all children have experienced at least one rota- virus infection by age five. Rotavirus accounts for ap- proximately two million hospitalizations and between 350,000 and 600,000 deaths in young children each year . Astrovirus has been found by several studies to be an important cause of acute gastroenteritis in young children; a prevalence study in the United Kingdom found that over 70% of five year-olds had antibodies to the virus [2-6]. Astrovirus has also been cited as an important cause of gastroenteritis in elderly populations [7,8]. Caliciviruses, in particular noroviruses, are the most important cause of epidemic, non-bacterial gastro- enteritis worldwide, affect both adults and children, and account for 40 to 50% of all foodborne gastroenteritis in the United States [9,10].
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Various molecular techniques have been exploited for the development of highly sensitive and rapid assays for the detec- tion of causative agents of viral gastroenteritis (16, 20, 26). Reverse transcription-PCR has reportedly increased the detec- tion rate of rotavirus A by up to 48% compared to EIA or electron microscopy (2, 17). Simpson et al. report that the detection of adenovirus was increased by more than 200% using PCR compared to results with EM (27). The screening of stool specimens for a range of gastrointestinal viruses using highly sensitive molecular methods would provide an indica- tion of the true prevalence of the causative agents of acute gastroenteritis in the pediatric patient cohort. In particular, rotavirus C prevalence remains largely unknown due to the * Corresponding author. Mailing address: Department of Microbi-
Although we identified multiple risk factors asso- ciated with viral GE hospitalization as well as several protective factors, our multivariate model as a whole failed to demonstrate high sensitivity or specificity in identifying those infants hospitalized. The area of 0.6 under the ROC curve obtained using this model is not much different from 0.5, which would be found by random guessing of infants at high risk for hos- pitalization. Based on our model, even if the rotavi- rus vaccine were 100% effective in preventing dehy- drating diarrhea, at least 90% of infants would need vaccination to protect all children from serious dis- ease resulting in hospitalization.
It has been proposed that the association of ASV with gas- troenteritis has been underestimated because infection with this virus generally results in a milder and far less contagious form of this disease (7, 16, 27, 29). However, several examples of viral gastroenteritis in children below the age of 5 years have been observed as mixed infections of RV with NV, RV with ASV, NV with ASV, and RV with other viral pathogens (5, 27, 34). Moreover, because of the availability of molecular diag- nostics in recent years, the coexistence of multiple viral patho- gens has now been confirmed in a number of cases of gastro- enteritis, and a variety of NV genotypes have also now been detected from epidemic outbreaks of this disease (23, 36, 38). In our current report, we describe an occurrence of coinfec- tion of NV and ASV in an acute gastroenteritis outbreak on a research ship. Genogrouping of the NV-positive samples was performed by a dot blot hybridization method, and all of the isolates were found to be of the GII genogroup. One recom- binant NV isolate, Minato/14, was identified as a recombinant NV strain of GII/6 and GII/1. In addition, nine NV isolates were classified into three NV genotypes (GII/1 [Minato/10], * Corresponding author. Mailing address: Division of Virology,
G astroenteritis stands among the five principal causes of mor- tality by disease and morbidity at all ages worldwide. The most affected population is children under 5 years of age, where it accounts for the second cause of postneonatal death, with approx- imately 2.6 million deceased per year (1). Although the majority of deaths occur in developing countries, diarrheal disease is among the most common causes of illness worldwide, with approxi- mately 4,620 million episodes annually (1). Besides humans, all vertebrate species suffer from enteric diseases. Infections in farm animals can lead to large economic losses, while household pets, such as dogs and cats, are also affected. On the other hand, wild animals, such as deer, monkeys, bats, foxes, wolves, and boars, among others, can act as potential reservoirs for pathogens (2). Gastrointestinal (GI) infections are caused by a variety of patho- gens, including parasites, bacteria, and viruses. The characteriza- tion of pathogens causing GI infections of viral etiology has led to the establishment of a main group of pathogens (Rotavirus A [RV-A], Norwalk virus [NV], Human astrovirus [HAstV], and Hu- man adenovirus F [HAdV-F]) (3) for which specific diagnostic tests were developed (4). Tests for secondary or rare viruses are available but are usually restricted to experimental use. Routine diagnostic methods for viral gastroenteritis are nowadays based on the detection of virus components by immunoassays or by molecular methods (5, 6, 7, 8), with the majority of these tests designed to evaluate only a single pathogen at a time.
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There are few data available about rotavirus type circulation in Spain (10, 12, 47). It has been estimated that rotavirus infections accounted for 25% of hospitalizations for gastroen- teritis in Spain in one year (46), with a seasonal pattern of incidence during the cooler months of the year. In October 1998, the Viral Gastroenteritis Study Group carried out a pilot prospective program to undertake the surveillance and char- acterization of rotavirus strains causing annual epidemics of severe diarrhea in young children. The program was designed to monitor the antigenic variation of rotaviruses before release of a rotavirus vaccine in Spain. The study relied on the design, cooperation, and participation of the National Microbiology Center of Spain. We describe the frequency and temporal distribution of human group A rotavirus types among patients admitted to a Madrid children’s hospital during a 4-year pe- riod.
Transmissible gastroenteritis coronavirus (TGEV) is an enteropathogenic coronavirus that causes diarrhea in pigs and is associated with high morbidity and mortality in sucking piglets. S1 is one of two protein domains in the spike (S) glycoprotein and is responsible for enteric tropism, sialic acid recognition, and host receptor binding. Although there has been extensive research on the S1 protein of TGEV, little is known about the intracellular role of TGEV-S1. In the present study, we used yeast two-hybrid screening of a cDNA library from porcine intestinal cells to identify proteins that interact with TGEV-S1. Among 120 positive clones from the library, 12 intracellular proteins were identified after sequencing and a BLAST search. These intracellular proteins are involved in protein synthesis and degradation, bio- logical signal transduction, and negative control of signaling pathways. Using a glutathione-S-transferase (GST) pull- down assay and Co-IP, we found that UBXN1 interacts with the S1 protein. Here, we observed that TGEV infection led to increased UBXN1 expression levels during the late phase of infection in IPEC-J2 cells. Inhibition of UBXN1 in IPEC-J2 cells via siRNA interference significantly decreased the viral titer and downregulated the expression of S1. UBXN1 overexpression significantly increased the viral copy number. Additionally, we provided data suggesting that UBXN1 negatively regulates IFN-β expression after TGEV infection. Finally, our research indicated that UBXN1 plays a vital role in the process of TGEV infection, making it a candidate target for the development of a novel antiviral method.
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Gastroenteritis is the inflammation of intestines and stomach which presents with vomiting, fever, abdominal pain and diarrhea. It could be persistent, acute, or chronic, and can also be classified as infectious or non-infectious. Despite improvement in management, the mortality can reach up to 17,000. In this study, our aim was to understand the various etiologies that cause gastroenteritis in adults, and also discuss methods of management. We conducted this review using a comprehensive search of MEDLINE, PubMed and EMBASE from January 1994 to March 2017. The following search terms were used: acute gastroenteritis, diarrheal disease, viral gastroenteritis, bacterial gastroenteritis, diagnoses of gastroenteritis. Each year, more than 350 million cases of acute gastroenteritis occur in the United States only. The largest portion of gastroenteritis cases is due to viral infections. Therefore, the empiric use of antibiotics is usually not recommended. However, in selected patients, empiric antibiotics therapy is indicated and is associated with significant improvement and decrease in mortality. The primary goal of management of gastroenteritis is treating dehydration.
5 RNA was extracted from 140 µl of 10% stool suspensions using the QIAamp Viral RNA extraction kit (QIAGEN, CA, USA), and immediately stored at −80ºC prior NoV detection. Real time RT-PCR was performed on an ABI 7500 Real Time PCR System (Applied Biosystems, Foster City, CA, USA) using primers and probes previously described  and the SuperScript III Platinum One-Step Quantitative RT-PCR System (Invitrogen, CA, USA). Briefly, the assay was carried out in a 25 µl final reaction mixture containing 5 µl of purified RNA with final concentrations of primers and probes of 600 and 300 nM, respectively. The thermal cycling conditions were carried out as follows: a RT step at 55 ºC for 30 min, an initial denaturation step at 95 ºC for 10 min, 45 cycles of PCR amplification at 95 ºC for 15 s, and at 60 ºC for 1 min. A 10-fold serial dilution of a plasmid containing the ORF1/2 junction was used to generate standard curves for virus quantification. Forty cycles were used in the reaction and samples with a cycle threshold <40 were regarded as positive.
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A data warehouse was queried for all patients aged 6 months to 6 years of age presenting to the ED between January 1, 2010, and January 31, 2016, with one of the International Classiﬁcation of Diseases, Ninth Revision (ICD-9) and International Classiﬁcation of Diseases, 10th Revision (ICD-10) codes consistent with the diagnosis of gastroenteritis (see Supplemental Information for full list of codes). Patients were excluded from this analysis retrospectively if they had a coexisting medical condition (identi ﬁ ed from the patient ’ s electronic problem list or diagnosis codes) that might lead a provider to choose a different treatment strategy or would frequently present with vomiting for reasons other than gastroenteritis (see Supplemental Table 2 for list of exclusion codes). Patients were also excluded if they were admitted to a subspecialty medical unit, surgical unit, or ICU or had ED lengths of stay . 10 hours
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Results: Weekly follow-up of the cohort consisting of 3000 participants will provide incidence estimates of AG. Fur- thermore, information collected will be used to assess risk factors for experiencing an episode of AG, to explore deter- minants for help seeking, and to characterise the socio-economic impact of AG including absence from work and inability to perform daily activities. Aetiology of AG is determined by investigating stool samples from symptomatic participants. Finally, stool samples from participants collected during an asymptomatic period will be used to assess the prevalence of enterohaemorrhagic E. coli, Campylobacter spp., Salmonella spp. and Shigella spp. as well as of resist- ance to different antibiotics (extended-spectrum beta-lactamase-, fluoroquinolone- and carbapenemase-resistance). Keywords: Research proposal, Cohort study, Acute gastroenteritis, Burden of disease, Incidence, Aetiology, Antibiotic resistance, Switzerland
In the acute gastroenteritis group, hyperamylasemia was recorded in 28 (17%) of the 164 cases with an identified microorganism in stool samples and in 22 (6.4%) of the 343 cases without a microbiological diagnosis (P < 0.01). Hyperamylasemia was significantly associated with the severity of gastroenteritis, and the severity of gastroen- teritis was significantly associated with the detectability of microorganisms in stool samples [severity score, grade 2 or 3 in 156 (98%) of patients with positive stool samples versus 176 (51.4%) in patients with negative stool samples, P < 0.01, Table 1I] . Among patients with positive stool samples, Salmonella spp . and in particular S. enteritidis, was the microorganism most frequently associated with hyperamylasemia [17/84 (20.2 %) and 10/45 (22.2%), respectively], followed by Rotavirus , Clostridium difficile and Campylobacter spp. (Fig. 1). In 5 patients Salmonella infection was accompained by sep- sis (bacteremia in presence of systemic signs and symp- toms of acute infection): all these cases had amylasemia in the normal range. The patient with clinical features of acute pancreatitis and the other two cases with amy- lasemia over four times the normal range had cholelithi- asis and Salmonella -related acute gastroenteritis.
We conducted a systematic review and meta-analysis of the literature in order to estimate the incidence of gastroenteritis in long term care facility (LTCF) residents from published accounts of infection surveillance. PubMed, Web of Science and Google Scholar were searched using keywords ‘ long-term care facility ’ , ‘ nursing home ’ , ‘ gastroenteritis ’ , ‘ surveillance ’ , and ‘ inci- dence’. We manually searched reference lists of all articles included. The number of cases of gastroenteritis and bed-days under surveillance was recorded so as to calculate incidence and assess the inﬂuence of the study country and case deﬁnition using random effects meta- analysis and regression. We included one trial and 14 surveillance studies in the analysis, with 47% (7/15) conducted after 1995. One study focused only on gastroenteritis in residents; the remainder considered a range of infections. There were 2 071 330 combined bed-days under surveillance and 717 cases of gastroenteritis. In all, 194 cases were associated with 10 outbreaks during these studies. We observed heterogeneity between studies, which may have been due to unreported clustering of gastroenteritis cases. The mean incidence of gastroen- teritis in LTCF residents was 0.40 (95% conﬁdence interval: 0.27e0.56) episodes per 1000 bed- days. Investigators conducting studies in the USA reported incidence three times lower than investigators in other countries. Use of a case deﬁnition developed speciﬁcally for LTCFs was not associated with a higher incidence of gastroenteritis. From our analysis, residents could expect to experience gastroenteritis once every 5e10 years, which is a lower rate than that estimated from point prevalence surveys. New studies are needed to better assess the inci- dence and causes of gastroenteritis in LTCF residents.
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Norovirus is considered the second most frequent cause of severe childhood gastroenteritis after rotavirus . Its prevalence in children with acute gastroenteritis is in the range of 6–48% . Although more than 30 genotypes, within genogroups GI, GII, and GIV, can infect humans , a single genotype, GII.4, has been associated with the vast majority of norovirus-related outbreaks and sporadic cases of gastroenteritis world- wide [18-20]. The GII.4 norovirus strains undergo con- tinuous processes of genetic/antigenic diversification and periodically generate novel strains through the accumu- lation of punctuate mutations or recombinations, and novel GII.4 variants emerge every 2–3 years [21,22].
(ii) Pecovirus. Pecoviruses (Peruvian stool-associated circo-like viruses [PeCVs]) are CRESS-DNA genomes that were ﬁrst identiﬁed in the feces of a patient during an outbreak of acute gastroenteritis in the Netherlands and later in samples of Peruvian children (55, 56). Subsequently, they were identiﬁed in other humans, pigs, a drome- dary camel, and a seal (55–58). Here we identiﬁed a genome sequence (HuPeCV- CMRHP60) of 2,937 bases made up of two ORFs that code for a capsid (372 aa) and a replicase protein (336 aa). Unlike other human PeCVs, the Cameroonian strain shared the same canonical nonamer (NANTATTAC) atop the predicted stem-loop structure with seal, dromedary, and porcine PeCV strains. The Rep showed 31 to 42% aa sequence identity to all other Rep genes, and a Rep-based phylogenetic analysis (Fig. 8C) showed that HuPeCV-CMRHP60 clustered together with pecovirus genomes from a seal and 3 human strains. Based on the cap protein (Fig. 8D), the Cameroonian strain was only 22 to 42% identical to all other pecoviruses and clustered only distantly from the seal strain, a porcine strain, and the human strains. This demonstrates the existence of a high level of genetic diversity within this group of circular DNA genomes, pointing to the possible existence of multiple species in this clade. Furthermore, we identiﬁed 2 incomplete sequences related to sewage-associated circular DNA mole- cules recovered from a sewage treatment oxidation pond in New Zealand (59), with only 38% aa identity on the Rep protein, further expanding the great diversity of CRESS-DNA genomes in the Cameroonian population.
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gastroenteritis (TGE) virus to identify the mechanisms of diarrhea in this disease and to better understand infectious diarrhea in humans. Using continuous segmental marker perfusion in four regions along the gut, we found significant increases in net intraluminal accumulation of water and electrolytes only in the proximal jejunum, the region infected by the virus. In this jejunal segment studied in vivo, unidirectional sodium flux, extracellular fluid (ECF) to lumen, significantly increased, lumen to ECF significantly decreased,
We have analyzed the intracellular transport of the spike (S) protein of infectious bronchitis virus (IBV), an avian coronavirus. Surface expression was analyzed by immunofluorescence microscopy, by surface biotin- ylation, and by syncytium formation by S-expressing cells. By applying these methods, the S protein was found to be retained intracellularly. Tyr1143 in the cytoplasmic tail was shown to be a crucial component of the retention signal. Deletion of a dilysine motif that has previously been suggested to function as a retrieval signal did not abolish intracellular retention. Treatment of the S proteins with endoglycosidases did not reveal any differences between the parental and the mutant proteins. Furthermore, all S proteins analyzed were post- translationally cleaved into the subunits S1 and S2. In coexpression experiments, the S protein was found to colocalize with a Golgi marker. Taken together, these results indicate that the S protein of IBV is retained at a late Golgi compartment. Therefore, this viral surface protein differs from the S proteins of transmissible gastroenteritis virus and severe acute respiratory syndrome coronavirus, which are retained at a pre-Golgi compartment or transported to the cell surface, respectively. The implications of these differences are discussed.