High frequency of rotavirus viremia in children with acute gastroenteritis: discordance of strains detected in stool and sera

Identification of Pulmonary Infections With Porcine Rotavirus A in Pigs With Respiratory Disease

While rotavirus (RV) is primarily known to cause gastroenteritis in many animals, several epidemiological studies have shown concurrent respiratory symptoms with fecal and nasal virus shedding. However, respiratory RV infections have rarely been investigated. By screening clinical samples submitted for diagnostic testing, porcine rotavirus A (RVA) was detected by quantitative reverse transcription PCR (qRT-PCR) in 28 out of 91 (30.8%) lungs obtained from conventionally reared pigs with respiratory signs. Among the positive cases, intensive RVA signals were mainly localized in alveolar macrophages (n = 3) and bronchiolar epithelial cells (n = 1) by RNAscope^® in situ hybridization (ISH). The signals of RVA in bronchiolar epithelial cells were verified by ISH with different probes, immunohistochemistry, and transmission electron microscopy. Furthermore, additional cases with RVA ISH-positive signals in alveolar macrophages (n = 9) and bronchial epithelial cells (n = 1) were identified by screening 120 archived formalin-fixed and paraffin-embedded lung samples using tissue microarrays. Overall, our study showed a high frequency of RVA detection in lungs from conventional pigs with respiratory disease. Further research is needed to determine if RVA infection in the respiratory epithelium correlates with nasal shedding of rotavirus and its contribution to respiratory disease.

Blood virosphere in febrile Tanzanian children

Viral infections are the leading cause of childhood acute febrile illnesses motivating consultation in sub-Saharan Africa. The majority of causal viruses are never identified in low-resource clinical settings as such testing is either not part of routine screening or available diagnostic tools have limited ability to detect new/unexpected viral variants. An in-depth exploration of the blood virome is therefore necessary to clarify the potential viral origin of fever in children. Metagenomic next-generation sequencing is a powerful tool for such broad investigations, allowing the detection of RNA and DNA viral genomes. Here, we describe the blood virome of 816 febrile children (<5 years) presenting at outpatient departments in Dar es Salaam over one-year. We show that half of the patients (394/816) had at least one detected virus recognized as causes of human infection/disease (13.8% enteroviruses (enterovirus A, B, C, and rhinovirus A and C), 12% rotaviruses, 11% human herpesvirus type 6). Additionally, we report the detection of a large number of viruses (related to arthropod, vertebrate or mammalian viral species) not yet known to cause human infection/disease, highlighting those who should be on the radar, deserve specific attention in the febrile paediatric population and, more broadly, for surveillance of emerging pathogens.Trial registration: ClinicalTrials.gov identifier: NCT02225769.

The control of diarrhea, the case of a rotavirus vaccine

[No disponible]

Rotavirus antigenemia as a common event among children hospitalised for severe, acute gastroenteritis in Belém, northern Brazil

Background

Rotavirus antigenemia and RNAemia (the presence of rotavirus RNA in serum) have been commonly identified among paediatric patients with acute gastroenteritis. In this study we examined the association between rotavirus antigenemia and clinical features, and sought to determine the genotypes of rotaviruses detected in paired stool and serum samples.

Methods

Paired stool and serum samples were obtained from children hospitalised for acute gastroenteritis in Belém, Brazil, between June 2012 and June 2015. The 20-point Vesikari scoring system was used to assess the disease severity upon a retrospective medical record review. Stool and serum samples were primarily screened for the presence of rotavirus antigen using a commercial ELISA assay. The rotavirus isolates from stool and serum samples were genotyped by using the classical reverse-transcriptase polymerase chain reaction (RT-PCR) and/or through nucleotide sequencing of VP4 and VP7 genes. Viral load was estimated using real-time RT-PCR.

Results

In total rotavirus antigen was detected in 109 (24.2%) stool samples from 451 children, whereas antigenemia occurred in 38.5% (42/109) of these patients. We demonstrated that patients positive for rotavirus RNA in paired stool and serum samples were more likely to have a higher frequency of vomiting episodes in a 24-h period (p = 0.0035). Our findings also suggested that children not vaccinated against rotavirus are more likely to develop antigenemia, as compared to those given at least one vaccine dose (p = 0.0151). G12P [8] and G2P [4] genotypes were predominant throughout the study period, accounting for 52.3% (57/109) and 27.5% (30/109) of the typed isolates, respectively. Ten stool-serum pairs could be typed for VP4 and VP7 genes. Seven of these pairs showed concordant results with G2P [4] genotype being detected in stool and serum samples, whereas discrepancies between genotypes (G2P [4]/G2P[NT] and G12P [8]/G2P[NT]) were seen in three pairs.

Conclusions

Rotavirus antigenemia and RNAemia occur in a significant number of children hospitalised for acute gastroenteritis in Belém, Brazil, and may contribute to a greater disease severity, particularly translated into a greater number of vomiting episodes. This study documented a high concordance of genotypes detected in a subgroup of paired stool and serum samples.

Electronic supplementary material

The online version of this article (10.1186/s12887-019-1535-2) contains supplementary material, which is available to authorized users.

Trends in Rate of Seizure-Associated Hospitalizations Among Children <5 Years Old Before and After Rotavirus Vaccine Introduction in the United Sates, 2000-2013

Background

Rotavirus is a common cause of acute gastroenteritis and has also been associated with generalized tonic-clonic afebrile seizures. Since rotavirus vaccine introduction, hospitalizations for treatment of acute gastroenteritis have decreased. We assess whether there has been an associated decrease in seizure-associated hospitalizations.

Methods

We used discharge codes to abstract data on seizure hospitalizations among children <5 years old from the State Inpatient Databases of the Healthcare Cost and Utilization Project. We compared seizure hospitalization rates before and after vaccine introduction, using Poisson regression, stratifying by age and by month and year of admission. We performed a time-series analysis with negative binomial models, constructed using prevaccine data from 2000 to 2006 and controlling for admission month and year.

Results

We examined 962899 seizure hospitalizations among children <5 years old during 2000-2013. Seizure rates after vaccine introduction were lower than those before vaccine introduction by 1%-8%, and rate ratios decreased over time. Time-series analyses demonstrated a decrease in the number of seizure-coded hospitalizations in 2012 and 2013, with notable decreases in children 12-17 months and 18-23 months.

Conclusions

Our analysis provides evidence for a decrease in seizure hospitalizations following rotavirus vaccine introduction in the United States, with the greatest impact in age groups with a high rotavirus-associated disease burden and during rotavirus infection season.

Neonatal rhesus monkeys as an animal model for rotavirus infection

AIM

To establish a rotavirus (RV)-induced diarrhea model using RV SA11 in neonatal rhesus monkeys for the study of the pathogenic and immune mechanisms of RV infection and evaluation of candidate vaccines.

METHODS

Neonatal rhesus monkeys with an average age of 15-20 d and an average weight of 500 g ± 150 g received intragastric administration of varying doses of SA11 RV ( 10⁷ PFUs/mL, 10⁶ PFUs/mL, or 10⁵ PFUs/mL, 10 mL/animal) to determine whether the SA11 strain can effectively infect these animals by observing their clinical symptoms, fecal shedding of virus antigen by ELISA, distribution of RV antigen in the organs by immunofluorescence, variations of viral RNA load in the organs by qRT-PCR, histopathological changes in the small intestine by HE staining, and apoptosis of small intestinal epithelial cells by TUNEL assay.

RESULTS

The RV monkey model showed typical clinical diarrhea symptoms in the 10⁸ PFUs SA11 group, where we observed diarrhea 1-4 d post infection (dpi) and viral antigen shed in the feces from 1-7 dpi. RV was found in jejunal epithelial cells. We observed a viral load of approximately 5.85 × 10³ copies per 100 mg in the jejunum at 2 dpi, which was increased to 1.09 × 10⁵ copies per 100 mg at 3 dpi. A relatively high viral load was also seen in mesenteric lymph nodes at 2 dpi and 3 dpi. The following histopathological changes were observed in the small intestine following intragastric administration of SA11 RV: vacuolization, edema, and atrophy. Apoptosis in the jejunal villus epithelium was also detectable at 3 dpi.

CONCLUSION

Our results indicate that we have successfully established a RV SA11 strain diarrhea model in neonatal rhesus monkeys. Future studies will elucidate the mechanisms underlying the pathogenesis of RV infection, and we will use the model to evaluate the protective effect of candidate vaccines.

A novel group A rotavirus associated with acute illness and hepatic necrosis in pigeons (Columba livia), in Australia

Cases of vomiting and diarrhoea were reported in racing pigeons in Western Australia in May, 2016. Morbidity and mortality rates were high. Similar clinical disease was seen in Victoria in December and by early 2017 had been reported in all states except the Northern Territory, in different classes of domestic pigeon–racing, fancy and meat bird–and in a flock of feral pigeons. Autopsy findings were frequently unremarkable; histological examination demonstrated significant hepatic necrosis as the major and consistent lesion, often with minimal inflammatory infiltration. Negative contrast tissue suspension and thin section transmission electron microscopy of liver demonstrated virus particles consistent with a member of the Reoviridae. Inoculation of trypsin-treated Vero, MDBK and MA-104 cell lines resulted in cytopathic changes at two days after infection. Next generation sequencing was undertaken using fresh liver samples and a previously undescribed group A rotavirus (genotype G18P[17]) of avian origin was identified and the virus was isolated in several cell lines. A q-RT-PCR assay was developed and used to screen a wider range of samples, including recovered birds. Episodes of disease have continued to occur and to reoccur in previously recovered lofts, with variable virulence reported. This is the first report of a rotavirus associated with hepatic necrosis in any avian species.

Systemic features of rotavirus infection

A growing body of evidence warrants a revision of the received/conventional wisdom of rotavirus infection as synonymous with acute gastroenteritis. Rotavirus vaccines have boosted our interest and knowledge of this virus, but also importantly, they may have changed the landscape of the disease. Extraintestinal spread of rotavirus is well documented, and the clinical spectrum of the disease is widening. Furthermore, the positive impact of current rotavirus vaccines in reducing seizure hospitalization rates should prompt a reassessment of the actual burden of extraintestinal manifestations of rotavirus diseases. This article discusses current knowledge of the systemic extraintestinal manifestations of rotavirus infection and their underlying mechanisms, and aims to pave the way for future clinical, public health and research questions.

Rotavirus antigenemia in children is associated with more severe clinical manifestations of acute gastroenteritis

BACKGROUND

Rotavirus (RV) antigenemia and RNAemia are common findings in rotavirus-infected children. Sporadic associations between RV antigenemia and extraintestinal manifestations of RV infection have been observed. We examined the clinical severity of RV gastroenteritis in patients with and without RV antigenemia or RNAemia.

METHODS

Stool, serum and whole blood samples were collected from children seen with acute gastroenteritis in Tampere University Hospital and studied for RV using reverse transcription polymerase chain reaction and enzyme-linked immunosorbent assay. Only exclusively RV-positive specimens were included into this study. The patients were divided into groups according to RV findings from stool, serum and blood specimens. Clinical manifestations were graded according to 20-point Vesikari scoring system.

RESULTS

Of 374 children, 155 (41%) had RV in their stools. Of these 155 children, 105 (67%) were found to have RV RNA in the serum; of those, 94 (90%) had also RV enzyme-linked immunosorbent assay antigen. Thus antigenemia occurred in 61% (94 cases) of RV-infected children all of whom had concomitant RNAemia. Neither antigenemia nor RNAemia were detected in 85 patients with non-RV gastroenteritis. Patients who had RV RNA and RV antigen in both serum and stools were more likely to have a higher level of fever and more severe vomiting than patients who had RV only in stools. G1 genogroup RV was more often associated with RNAemia and antigenemia than other genogroups combined.

CONCLUSION

Rotavirus antigenemia and viremia are commonly detected in children hospitalized for RV gastroenteritis and may be associated with increased severity of fever and vomiting.

[Human rotavirus vaccine]

Since the presentation of the clinical trial reports showing the excellent efficacy and safety of the two human rotavirus vaccines (Rotarix and RotaTeq), the human rotavirus vaccines have received worldwide attention. The two vaccines have been approved in more than 100 countries, and were included in routine immunization schedule in about 30 countries. The effectiveness of the two vaccines exceeded our expectations, and severe rotavirus gastroenteritis cases have been greatly reduced. Also in Japan, administration of Rotarix started just last November, and RotaTeq will be also started soon. On this occasion, composition, characteristics, and effectiveness of these vaccines are described, and some points relating to the vaccination such as intussusception, cross protection, shedding and so on are also discussed.

Rotavirus and biliary atresia: can causation be proven?

PURPOSE OF REVIEW

New knowledge on rotavirus infection in children and well established mouse models has renewed interest in whether rotavirus could cause biliary atresia, an idiopathic, obliterative infantile disease of bile ducts that is the primary indication for liver transplant in children.

RECENT FINDINGS

Studies in the rotavirus mouse model of biliary atresia indicate that infection of biliary epithelium is an inaugural event leading to biliary inflammation and obstruction, which is preceded by systemic spread of rotavirus, which also occurs during human rotavirus enteric infections. Viral factors, including rotavirus gene 4, are important for biliary infection and biliary atresia in mice. Specific host factors related to inflammatory processes (natural killer and T cells, interferon) are also critical, and a paucity of regulatory T cells in neonates may play a key role in pathogenesis in experimental biliary atresia. Rotavirus vaccination has substantially decreased rotavirus diarrheal disease worldwide and might enable demonstration of a cause-effect relationship between rotavirus infection and biliary atresia in humans.

SUMMARY

Rotavirus can be detected in the serum of mice and children and causes biliary atresia in neonatal mice. Approaches to re-examine whether rotavirus causes biliary atresia in children are discussed based on concepts from the mouse model of biliary atresia and rotavirus vaccination programs.

A first report on the characterization of rotavirus strains in Sierra Leone

In an effort to reduce the high mortalities associated with rotavirus infections, a number of African countries are considering introducing human rotavirus vaccines. The demonstrated safety and efficacy of the live-attenuate human rotavirus vaccines in several clinical trials worldwide has accelerated such initiatives. Although the percentage-mortality rates for Sierra Leone are top of the list for rotavirus-associated deaths in Africa, no study has reported the prevalent strains circulating within this country. In this study, stool specimens were collected from 128 Sierra Leonean children presenting with diarrhea in 2005. Almost 37.5% (48/128) were rotavirus positive by EIA, of which 89.6% (43/48) revealed a short electropherotype, and a further 6.98% (3/48) could not be assigned a PAGE pattern. Genotyping analysis revealed G2P[4] (30.23%), G2P[6] (13.95%), G8P[6] (11.63%), G2P[8] (4.65%), G8P[4] (4.65%), and G8P[8] (2%) strains. About 11% were only assigned VP7 genotypes (G2), while 20.9% had mixed G and P types. The frequent detection of G2 rotaviruses could be of concern considering data generated from some studies that suggests lower efficacy of Rotarix® vaccine against G2 rotaviruses. This underscores the need for extensive and continuous regional strain surveillance to support rotavirus vaccines introduction and guide future vaccine development efforts. Such information will be useful before considering administration of specific rotavirus vaccine candidates in countries like Sierra Leone where little is known about circulating rotavirus strains.

Molecular and immunohistochemical detection of rotavirus in urinary sediment cells of children with rotavirus gastroenteritis

This is the first report showing that rotavirus infects the urinary sediment cells in immunocompetent children with rotavirus gastroenteritis. We found that inclusion-bearing cells were frequently detected in the urine samples of patients with rotavirus gastroenteritis. These cells were positive for cytokeratin, which was sometimes coexpressed with rotavirus antigen, in our immunohistochemical analysis. Moreover, in nested RT-PCR experiments, we detected rotavirus double-stranded RNA in some urine samples of patients with rotavirus gastroenteritis. We concluded that rotavirus could lead to infection of the urinary sediment cells concomitantly with rotavirus gastroenteritis.

Immune mediators of rotavirus antigenemia clearance in mice

The immunological mediators that clear rotavirus antigenemia or viremia remain undefined. Immunodeficient mice and antibody transfer were used to test whether lymphocytes or rotavirus-specific serum antibodies are essential for resolving antigenemia. Clearance of antigenemia required lymphocytes, but neither T nor B lymphocytes were absolutely required. Transfer of convalescent-phase or nonneutralizing rotavirus-specific serum antibodies to the systemic compartment of severe-combined-immunodeficient (SCID) mice temporarily suppressed the onset or level of chronic rotavirus antigenemia. Our findings provide the first report demonstrating that clearance of rotavirus antigenemia and possibly viremia are mediated by multiple effector lymphocyte subsets and serum antibodies.

Global impact of rotavirus vaccines

The WHO has recently recommended the inclusion of rotavirus vaccine in the national immunization programs of all countries. In countries in the Americas, Europe and Australia that have adopted routine childhood immunization against rotavirus, significant reductions in the burden of severe childhood diarrhea have been observed. Besides protecting vaccinated children, disease rates also appear to be reduced in unvaccinated children, suggesting indirect benefits from vaccination (i.e., herd protection). Early clinical trial data from Africa and Asia are promising, and further efforts are needed to optimize the benefits of vaccination in developing countries where vaccines are likely to have their greatest impact.

Detection of rotavirus antigenemia in routinely obtained serum specimens to augment surveillance and vaccine effectiveness evaluations

BACKGROUND

: Antigenemia is common among children with rotavirus disease. Because obtaining stool specimens is cumbersome, we evaluated whether detection of antigenemia in sera obtained during routine clinical practice could augment rotavirus surveillance to assess the effect of vaccination.

METHODS

: We determined the sensitivity, specificity, and positive and negative predictive values of serum/plasma rotavirus antigen detection using fecal antigen positivity as the gold standard. Fecal specimens obtained by active surveillance and residual serum/plasma specimens obtained during routine clinical testing from children 15 days to 23 months of age presenting with acute gastroenteritis (AGE) to a children's hospital in Houston were tested for rotavirus using a commercially available enzyme immunoassay. Using case-control methods, we compared vaccine effectiveness (VE) using cases identified through serum/plasma testing versus stool testing.

RESULTS

: Of the 205 AGE patients with fecal specimens, 71 (35%) had a serum/plasma sample available. Among these 71 children, antigenemia was detected in 22 of 29 with rotavirus-positive fecal specimens (sensitivity = 75%; 95% confidence interval [CI] = 60%-91%) versus 2 of 42 children with rotavirus-negative fecal specimens (specificity = 95%; 95% CI = 89%-100%). The positive and negative predictive values of rotavirus antigenemia were 92% (95% CI = 81%-100%) and 85% (95% CI = 75%-95%), respectively. Thirty-four of 195 children with AGE without fecal specimens had serum/plasma available; 10 (29%) had rotavirus antigenemia. Three-dose VE using cases identified through serum/plasma testing was similar (VE = 84%; 95% CI = 25%-96%) to that using cases identified though fecal testing (VE = 85%; 95% CI = 55%-95%).

CONCLUSIONS

: Detection of antigenemia in routinely collected serum/plasma could augment identification of rotavirus disease for postlicensure evaluation of impact and effectiveness of rotavirus vaccination.

Characterization of group A rotavirus infections in adolescents and adults from Pune, India: 1993-1996 and 2004-2007

A total of 1,591 fecal specimens were collected in 1993-1996 and 2004-2007 from adolescents and adults with acute gastroenteritis in Pune, India for detection and characterization of rotavirus. At the two time points, group A rotavirus was detected in 8.6% and 16.2% of the adolescents and 5.2% and 17.2% of the adults, respectively. Reverse transcription-PCR with consensus primers followed by multiplex genotyping PCR detected common strains G1P[8], G2P[4], G3P[8], and G4P[8] in a total of 53.1% of the samples from 1993 to 1996, while the only prevalent strain identified in 2004-2007 was G2P[4] (23.5% of total). Uncommon rotavirus strains (G1P[4], G2P[8] G9P[6]/P[4]) increased from 7.8% (1993-1996) to 41.2% (2004-2007), while the prevalence of mixed rotavirus infections was high (39%/35%) at both time points. Mixed infections detected by multiplex PCR were confirmed by sequencing two or more individual genotype-specific PCR products of the VP7 and VP4 genes from the same sample. Phylogenetic analysis of the sequences showed circulation of a heterogeneous rotavirus strain population comprising genotypes G1 (lineages I and IIb), G2 (lineages I and IIb), G4 (lineage Ia), P[4] (lineages P[4]-5 and P[4]-1), P[8] (lineages P[8]-II and P[8]-III), and P[6] (M37-like lineage). The VP6 gene sequences of the nontypeable strains were most homologous to animal strains. This study documents the molecular epidemiology of rotavirus strains in adolescents and adults in India, and suggests that it may be important to monitor these strains over time for the potential impact on rotavirus vaccines under development for use in the Indian population. J. Med. Virol. 82:519-527, 2010. (c) 2010 Wiley-Liss, Inc.

VP7 and VP4 sequence analyses of rotavirus strains from Italian children with viraemia and acute diarrhoea

Information on genotypes or variants associated with systemic rotavirus infection is lacking. Seven viraemic children with acute rotavirus diarrhoea were evaluated. All faecal strains were genotyped (5 G1P[8] type, 1 G9P[8], 1 G1-G4P[8]). Only 3 of 7 blood strains were typeable (G1P[8], G4P8, and G1P[ND]). A discrepancy between faecal and blood VP7 amino acid sequences (Ser-->Asp at position 94) was found in the first child. Two amino acid substitutions (Ile-->Val and Asn-->Ser at position 106 and 113) in the VP4 sequences were demonstrated in the second child. Complete correspondence was found in the third child. All of the observed amino acid substitutions may be involved in rotavirus neutralisation. We speculate that during co-infection by multiple strains, a preferential extraintestinal dissemination of some variants may occur, possibly because of differential viral characteristics.

Viral infections: new and emerging

PURPOSE OF REVIEW

Viral gastrointestinal diseases are a leading cause of childhood death worldwide. Recognition of specific causes as they pertain to epidemiology, pathogenesis, treatment, and prevention is necessary for the clinician as scientific advances allow for greater understanding of the diseases. The present review summarizes these advances for commonly encountered causes of viral gastroenteritis.

RECENT FINDINGS

Implementation of rotavirus vaccine has decreased the burden of this disease in many communities, and advances in molecular testing of the virus increase the ability to test for the virus. The tools utilized to test for these viruses are quite sensitive however, and are limited to primarily research investigations. Associations between virus and other gastrointestinal diseases have been evaluated as well, as have the host factors contributing to susceptibility to these infections.

SUMMARY

Viral gastroenteritis is common, and specific viruses are difficult to identify. Testing of these viruses through PCR or electron microscopy as a research tool is important, as is recognition of host risk factors, epidemiologic issues, and development of prevention and treatment strategies by identifying virus transmission.