Introduction of rotavirus vaccines into national immunization programs (NIPs) could result in strain selection due to vaccine-induced selective pressure. This study describes the distribution and ...diversity of rotavirus genotypes before and after rotavirus vaccine introduction into the Australian NIP. State-based vaccine selection facilitated a unique comparison of diversity in RotaTeq and Rotarix vaccine states.
From 1995 to 2015, the Australian Rotavirus Surveillance Program conducted genotypic analysis on 13051 rotavirus-positive samples from children <5 years of age, hospitalized with acute gastroenteritis. Rotavirus G and P genotypes were determined using serological and heminested multiplex reverse-transcription polymerase chain reaction assays.
G1P8 was the dominant genotype nationally in the prevaccine era (1995-2006). Following vaccine introduction (2007-2015), greater genotype diversity was observed with fluctuating genotype dominance. Genotype distribution varied based on the vaccine implemented, with G12P8 dominant in states using RotaTeq, and equine-like G3P8 and G2P4 dominant in states and territories using Rotarix.
The increased diversity and differences in genotype dominance observed in states using RotaTeq (G12P8), and in states and territories using Rotarix (equine-like G3P8 and G2P4), suggest that these vaccines exert different immunological pressures that influence the diversity of rotavirus strains circulating in Australia.
Severe diarrhea from rotavirus remains an important cause of illness in infants. In this trial, investigators in Indonesia assessed the potential benefit of a neonatal rotavirus vaccine.
BACKGROUND:Rotavirus vaccines, RotaTeq and Rotarix, were introduced into the Australian National Immunization Program on July 1, 2007. The simultaneous introduction in different Australian states and ...territories provides a unique opportunity to compare the affect of each vaccine on the types of circulating rotavirus strains. This report describes the rotavirus genotypes responsible for the hospitalization of children during the first 2-year period after vaccine introduction.
METHODS:A total of 764 rotavirus-associated diarrheal cases were collected from children presenting to hospital in 10 Australian centers. Rotavirus genotype was determined using reverse transcription polymerase chain reaction assays.
RESULTS:G1P8 was the dominant genotype nationally (52%), followed by G2P4 (19.8%), G9P8 (12.2%), and G3P8 (11%). Differences in the prevalence rates of G2P4 and G3P8 were seen in the various states. G2P4 strains were more prevalent in states using Rotarix, whereas G3P8 strains were more prevalent in states using RotaTeq.
CONCLUSIONS:Differences in rotavirus genotypes were observed across Australia, which suggest that different immune pressures are exerted by the different vaccines, but do not necessarily imply lack of protection by either vaccine. These differences may simply be related to the variation that can occur because of natural annual fluctuation in rotavirus strain prevalence.
The role of bacteriophage in Crohn's disease (CD) is unknown. This study investigated the abundance of phages in ileal and colonic samples from pediatric CD patients and controls.
Ileal and colonic ...biopsies from 6 CD patients, gut wash samples from 3 CD patients, and ileal biopsies from 6 noninflammatory bowel disease patients (controls) were analyzed for the presence of bacteriophage using 454 high-throughput pyrosequencing. A sequence-independent single-primer amplification method was used to amplify viral sequences.
A total of 186,143 high quality reads were obtained from the 4 sample populations. Contigs and sequence clusters (generated from unassembled singletons) were aligned with sequences from the National Center for Biotechnology Information viral reference database and analyzed by MEGAN. The largest number of viral hits was obtained from the CD gut wash samples (n = 691), followed by CD ileal samples (n = 52), control ileum samples (n = 20), and CD colonic samples (n = 1). The most abundant virus sequences identified belonged to the Caudovirales phage.
Our study characterized a diverse phage community in the gut of CD patients. In this study, we have identified differences in phage composition between CD patients and control individuals. The large abundance of phages in CD ileum tissue and CD gut wash sample suggests a role of phage in CD development. The role of phage dysbiosis in CD is currently unknown but opens up a new area of research.
Summary Background Despite the success of rotavirus vaccines, suboptimal vaccine efficacy in regions with a high burden of disease continues to present a challenge to worldwide implementation. A ...birth dose strategy with a vaccine developed from an asymptomatic neonatal rotavirus strain has the potential to address this challenge and provide protection from severe rotavirus disease from birth. Methods This phase 2a randomised, double-blind, three-arm, placebo-controlled safety and immunogenicity trial was undertaken at a single centre in New Zealand between Jan 13, 2012, and April 17, 2014. Healthy, full-term (≥36 weeks gestation) babies, who weighed at least 2500 g, and were 0–5 days old at the time of randomisation were randomly assigned (1:1:1; computer-generated; telephone central allocation) according to a concealed block randomisation schedule to oral RV3-BB vaccine with the first dose given at 0–5 days after birth (neonatal schedule), to vaccine with the first dose given at about 8 weeks after birth (infant schedule), or to placebo. The primary endpoint was cumulative vaccine take (serum immune response or stool shedding of vaccine virus after any dose) after three doses. The immunogenicity analysis included all randomised participants with available outcome data. This trial is registered with the Australian New Zealand Clinical Trials Registry, ACTRN12611001212943. Findings 95 eligible participants were randomised, of whom 89 were included in the primary analysis. A cumulative vaccine take was detected in 27 (90%) of 30 participants in the neonatal schedule group after three doses of RV3-BB vaccine compared with four (13%) of 32 participants in the placebo group (difference in proportions 0·78, 95% CI 0·55–0·88; p<0·0001). 25 (93%) of 27 participants in the infant schedule group had a cumulative vaccine take after three doses compared with eight (25%) of 32 participants in the placebo group (difference in proportions 0·68, 0·44–0·81; p<0·0001). A serum IgA response was detected in 19 (63%) of 30 participants and 20 (74%) of 27 participants, and stool shedding of RV3-BB was detected in 21 (70%) of 30 participants and 21 (78%) of 27 participants in the neonatal and infant schedule groups, respectively. The frequency of solicited and unsolicited adverse events was similar across the treatment groups. RV3-BB vaccine was not associated with an increased frequency of fever or gastrointestinal symptoms compared with placebo. Interpretation RV3-BB vaccine was immunogenic and well tolerated when given as a three-dose neonatal or infant schedule. A birth dose strategy of RV3-BB vaccine has the potential to improve the effectiveness and implementation of rotavirus vaccines. Funding Australian National Health and Medical Research Council, the New Zealand Health Research Council, and the Murdoch Childrens Research Institute.
Molecular analysis of bacterial 16S rRNA genes has made a significant contribution to the identification and characterisation of bacterial flora in the human gut. In particular, this methodology has ...helped characterise bacterial families implicated in the aetiology of inflammatory bowel disease (IBD). In this study we have used a genus specific bacterial 16S PCR to investigate the prevalence and diversity of Pseudomonas species derived from the ileum of children with Crohn's disease (CD), and from control children with non-inflammatory bowel disease (non-IBD) undergoing their initial endoscopic examination. Fifty eight percent of CD patients (18/32) were positive using the Pseudomonas PCR, while significantly fewer children in the non-IBD group, 33% (12/36), were PCR positive for Pseudomonas (p<0.05, Fischer's exact test). Pseudomonas specific 16S PCR products from 13 CD and 12 non-IBD children were cloned and sequenced. Five hundred and eighty one sequences were generated and used for the comparative analysis of Pseudomonas diversity between CD and non-IBD patients. Pseudomonas species were less diverse in CD patients compared with non-IBD patients. In particular P.aeruginosa was only identified in non-IBD patients.
Celotno besedilo
Dostopno za:
DOBA, IZUM, KILJ, NUK, PILJ, PNG, SAZU, SIK, UILJ, UKNU, UL, UM, UPUK
Background. RotaTeq vaccine was introduced into the Australian National Immunisation Program in 2007. This study identified and characterised rotavirus strains excreted by infants who presented with ...symptoms of gastroenteritis following recent RotaTeq vaccination. Methods. Fecal samples (N = 61) from children who developed gastroenteritis following recent RotaTeq vaccination were forwarded to the Australian Rotavirus Surveillance Program (ARSP). RotaTeq-positive samples were genotyped and regions of the VP3, VP4, VP6, and VP7 genes were sequenced. Also, 460 rotavirus-positive ARSP routine surveillance samples were analyzed by dot-blot Northern hybridization to detect RotaTeq vaccine-derived strains circulating in the community. Results. Thirteen of the 61 samples collected from infants developing gastroenteritis after RotaTeq vaccination contained vaccine-derived (vd) rotavirus strains. Of these, 4 contained a vdG1P8 strain derived by reassortment between the G1P5 and G6P8 parental vaccine strains. Northern hybridization analysis of 460 surveillance samples identified 3 samples that contained RotaTeq vaccine—derived strains, including 2 vdG1P8 reassortant vaccine strains. Conclusions. During replication and excretion of RotaTeq vaccine, reassortment of parental strains can occur. Shedding of RotaTeq vaccine strains in 7 of 13 infants was associated with underlying medical conditions that may have altered their immune function. The benefits of vaccination outweigh any small risk of vaccine-associated gastroenteritis.
This study aimed to investigate risk factors for the development of intussusception in infants in a developing country with a suspected high incidence and in a developed country with a low incidence.
...A prospective case-control study of infants <2 years of age with idiopathic intussusception confirmed by air enema or surgery was conducted at the National Hospital of Paediatrics (NHP), Vietnam (n = 533) and the Royal Children’s Hospital (RCH), Australia (n = 51). Diagnosis was validated in a subset (84% NHP; 67% RCH) by an independent blinded radiologist. Risk factor assessment was performed using a standardized questionnaire. Stool specimens were assayed for bacterial, viral, and parasitic agents.
The incidence of intussusception in Vietnam was 302/100,000 in infants <1 year of age (95% CI: 258-352), substantially higher than in Australia (71/100,000). A strong association with adenovirus infection was observed at both sites (cases positive at NHP: 34%, OR 8.2; cases positive at RCH: 40%, OR 44). No association was identified between intussusception and rotavirus, other enteric pathogens, oral polio vaccine, feeding practices, or living conditions.
The incidence of intussusception in infants was markedly higher in Vietnam than in Australia. A strong association between adenovirus infection and intussusception was identified at both sites suggesting that adenovirus may play a role in the etiology of intussusception.
Rotavirus infection is thought to be confined to the intestine. Reports of rotavirus RNA in the cerebral spinal fluid and serum of children infected with rotavirus suggest the possibility that ...rotavirus escapes the intestine into the circulatory system. We assessed whether rotavirus antigen, RNA, or both, were present in serum samples from immunocompetent rotavirus-infected children and animals.
We obtained sera from immunocompetent mice, rats, rabbits, and calves 1–10 days after inoculation with rotavirus or matched vehicle. We obtained sera retrospectively from immunocompetent children diagnosed with rotavirus diarrhoea (n=33), healthy children (n=6) and adults (n=12), children convalescing from rotavirus (n=6), and children with non-rotavirus diarrhoea (n=11). Samples were analysed for the presence of rotavirus antigen or RNA by EIA or RT-PCR, respectively.
Rotavirus antigen was present in sera from rotavirus-infected animals, but not in sera from control animals. Infectious rotavirus or rotavirus RNA was detected in sera of mice and calves, respectively. Antigen was present in 22 of 33 serum samples from children with confirmed rotavirus infection but in none of 35 samples from controls. Detection of serum antigen was inversely related to the number of days between symptom onset and sample collection, and directly related to stool antigen concentration. Rotavirus RNA was detected by RT-PCR in three of six rotavirus-positive sera.
Rotavirus can escape the gastrointestinal tract in children, resulting in antigenaemia and possible viraemia. This finding is important for the understanding of the pathogenesis, immunology, and clinical manifestations of rotavirus infection.
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