Karen Boniface

Distribution of rotavirus genotypes after introduction of rotavirus vaccines, Rotarix® and RotaTeq®, into the National Immunization Program of Australia.

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: G1P[8] was the dominant genotype nationally (52%), followed by G2P[4] (19.8%), G9P[8] (12.2%), and G3P[8] (11%). Differences in the prevalence rates of G2P[4] and G3P[8] were seen in the various states. G2P[4] strains were more prevalent in states using Rotarix, whereas G3P[8] 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.

Mycobacterium avium subspecies paratuberculosis in children with early-onset Crohn's disease.

Background: Mycobacterium avium subspecies paratuberculosis (MAP) is the most enduring infectious candidate that may be associated with inflammatory bowel disease (IBD). It is possible that the inconsistencies in the prevalence studies of MAP in adults reflect clinical differences in adult patients studied, including duration of disease and treatment regimens, and also in lack of specificity of some of the assays used. The aim was to determine the presence of MAP in children with symptoms of Crohns disease (CD) and ulcerative colitis (UC), using gut biopsy tissue and peripheral blood mononuclear cells (PBMC) collected at initial endoscopic examination prior to clinical treatment. Methods: Mucosal biopsies and/or PBMC specimens were collected from a total of 142 children, comprising 62 with CD, 26 with UC, and 54 with non‐IBD. MAP‐specific IS900 polymerase chain reaction (PCR) analysis was performed on all biopsies and PBMC specimens. Conventional MAP culture technique was performed on a subset of 10 CD, 2 UC, and 4 non‐IBD patients to isolate MAP. Results: MAP was identified by IS900 PCR significantly more often in mucosal biopsies from CD 39% (22/56) than from non‐IBD 15% (6/39) patients (P < 0.05), and in PBMC from CD 16% (8/50) than from non‐IBD 0% (0/31) patients (P < 0.05). Viable MAP were cultured from mucosal biopsies from 4/10 CD, 0/2 UC, and 0/4 non‐IBD patients, but were not cultured from PBMC specimens. Conclusions: This unique study on the occurrence of MAP in gut tissue and blood from pediatric IBD patients suggests the possible involvement of MAP in the early stages of development of CD in children. Inflamm Bowel Dis 2009

Rotavirus vaccine induced diarrhea in a child with severe combined immune deficiency.

To the Editor: The first case report on a patient who developed Churg-Strauss syndrome (CSS) after therapy with omalizumab, the anti-IgE recombinant humanized mAb, was described by Winchester et al in 2006. Later, several similar cases were reported in the medical literature; the authors suggested a possible role for anti-IgE treatment in the emergence of CSS and recommended careful monitoring of emerging symptoms of this vasculitis in patients treated with omalizumab. In contrast, Giavina Bianchi et al presented the case of a patient with CSS with uncontrolled asthma that improved with omalizumab treatment without increase of CSS clinical severity. The authors hypothesized that steroid tapering during omalizumab therapy could have caused CSS clinical appearance. Here we describe the case of a 42-year-old Caucasian man with a 5 year history of asthma. One year after asthma onset, blood hypereosinophilia became evident (1600/mL), and the patient J ALLERGY CLIN IMMUNOL

Identification of Strains of RotaTeq Rotavirus Vaccine in Infants With Gastroenteritis Following Routine Vaccination

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 vdG1P[8] strain derived by reassortment between the G1P[5] and G6P[8] parental vaccine strains. Northern hybridization analysis of 460 surveillance samples identified 3 samples that contained RotaTeq vaccine-derived strains, including 2 vdG1P[8] 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.

Rotavirus strain surveillance—An Australian perspective of strains causing disease in hospitalised children from 1997 to 2007

This study documents rotavirus strains causing severe disease in Australian children during the pre-vaccine era. During the period 1997-2007, rotavirus strains from national multi-centre hospital-based surveillance in Australia were analysed for G and P types. G1P[8] was the dominant genotype identified during the 11-year study, with intermittent peaks associated with genotypes G2P[4], G3P[8] and G9P[8]. The results provide baseline information of the G and P genotypes causing disease in Australian children, and highlight the unpredictable changes in genotype incidence that can occur on both a local and national level. To be optimally effective, rotavirus vaccines must prevent disease caused by all common rotavirus genotypes.

Phylogenetic Analysis of Rotavirus A NSP2 Gene Sequences and Evidence of Intragenic Recombination

The rotavirus non-structural protein NSP2 is one of the earliest and most abundant viral proteins produced during infection. This protein has multiple essential roles in the replication cycle involving RNA binding, viroplasm formation, helicase and can hydrolyse the γ-phosphate of RNA and NTPs acting as an RTPase and NTPase. In studying sequences from rotavirus strains isolated in Australia between 1984 and 2009, the NSP2 gene was seen to be highly conserved and clustered with defined NSP2 genotypes N1 and N2 according to the full genome based rotavirus classification system. Phylogenetic analysis indicated that NSP2 gene sequences isolated from Australian rotavirus strains formed four distinct lineages. Temporal variation was observed in several clusters during the 26 year period, with lineage D identified throughout the entire study period and lineage A only detected since 1999. Phylogenetic analysis and dendrograms identified NSP2 genes that exhibited reassortment between different virus VP7 genotypes, as well as a sequence from a human strain that grouped closely with the NSP2 genes of bovine rotavirus strains. This study also identified a sequence that fell between lineages and exhibited evidence of recombination, the first time that intergenic recombination has been detected in a NSP2 gene sequence. This study increases the understanding of the evolution mechanisms of NSP2 in view of improved vaccine design.

Non‐structural protein NSP2 induces heterotypic antibody responses during primary rotavirus infection and reinfection in children

Rotaviruses are the single most important causes of severe acute diarrhoea in children worldwide. Despite success in developing vaccines, there is still a lack of knowledge about many components of the immune response, particularly those to non‐structural proteins. This study established radioimmunoprecipitation (RIP) assays using labeled G1P[8], G2P[4], and G4P[6] human rotaviruses to examine the spectrum and duration of rotavirus antibodies in sera collected sequentially for 18–36 months from 27 children after hospitalization for primary rotavirus gastroenteritis. Five children experienced rotavirus re‐infections. Primary responses detected to non‐structural protein NSP2 declined to baseline after 100–150 days. Responses were heterotypic between NSP2 of G1P[8] and G4P[8] rotaviruses. Re‐infections after 465–786 days boosted antibody levels to NSP2of both serotypes, together with the appearance of anti‐NSP2 to G2P[4], even though there was no evidence of infection with this serotype. We developed an enzyme‐immunoassay to measure sequential levels of anti‐NSP2 IgG and IgA, using recombinant (heterotypic) NSP2 derived from SA11 (G3P[2]). Anti‐NSP2 IgG and IgA were detected in sera from 23/23 (100%) and 18/24 (75%) of children after primary infection, declined to baseline after 100–150 days, were boosted after rotavirus re‐infections, and again declined to baseline 150 days later. Anti‐NSP2 IgA was also detected after primary infection, in duodenal juice from 14/16 (87%), and faecal extract from 11/19 (57%) of children. Sequential estimation of anti‐NSP2 EIA levels in sera could be a sensitive index of rotavirus infection and re‐infection. The potential of anti‐NSP2 to limit viral replication after re‐infection deserves further study. J. Med. Virol. 80:1090–1098, 2008.

Surveillance and Molecular Characterization of Group A Rotaviruses in Goroka, Papua New Guinea

In this study, we investigated the molecular epidemiology of group A rotaviruses in cases of acute gastroenteritis in Goroka, Papua New Guinea. From April 2008 through November 2010, 813 diarrheal stool samples were collected from children < 5 years of age hospitalized with acute gastroenteritis. Rotavirus antigen was detected in 31.2% of samples using a commercial enzyme-linked immunosorbent assay. Genotyping revealed the presence of the globally circulating strains G1P[8] (50.0%), G3P[8] (23.0%), and G2P[4] (8.2%). The globally emerging strains G9 and G12 were detected in 1.2% and 6.1% of samples, respectively. Mixed infections were detected in a high proportion of samples (11.9%), with 9.0% and 3.7% of samples displaying multiple G and P genotypes, respectively.

Rotavirus shedding following administration of RV3-BB human neonatal rotavirus vaccine

ABSTRACT The RV3-BB human neonatal rotavirus vaccine aims to provide protection from severe rotavirus disease from birth. A phase IIa safety and immunogenicity trial was undertaken in Dunedin, New Zealand between January 2012 and April 2014. Healthy, full-term (≥ 36 weeks gestation) babies, who were 0–5 d old were randomly assigned (1:1:1) to receive 3 doses of oral RV3-BB vaccine with the first dose given at 0–5 d after birth (neonatal schedule), or the first dose given at about 8 weeks after birth (infant schedule), or to receive placebo (placebo schedule). Vaccine take (serum immune response or stool shedding of vaccine virus after any dose) was detected after 3 doses of RV3-BB vaccine in >90% of participants when the first dose was administered in the neonatal and infant schedules. The aim of the current study was to characterize RV3-BB shedding and virus replication following administration of RV3-BB in a neonatal and infant vaccination schedule. Shedding was defined as detection of rotavirus by VP6 reverse transcription polymerase chain reaction (RT-PCR) in stool on days 3–7 after administration of RV3-BB. Shedding of rotavirus was highest following vaccination at 8 weeks of age in both neonatal and infant schedules (19/30 and 17/27, respectively). Rotavirus was detected in stool on days 3–7, after at least one dose of RV3-BB, in 70% (21/30) of neonate, 78% (21/27) of infant and 3% (1/32) placebo participants. In participants who shed RV3-BB, rotavirus was detectable in stool on day 1 following RV3-BB administration and remained positive until day 4–5 after administration. The distinct pattern of RV3-BB stool viral load demonstrated using a NSP3 quantitative qRT-PCR in participants who shed RV3-BB, suggests that detection of RV3-BB at day 3–7 was the result of replication rather than passage through the gastrointestinal tract.

Molecular characterisation of rotavirus strains detected during a clinical trial of the human neonatal rotavirus vaccine (RV3-BB) in Indonesia

Highlights • Equine-like G3P[8] the major cause of gastroenteritis during RV3-BB efficacy trial.• The Indonesian equine-like G3P[8] strain was genetically similar to Hungarian and Spanish strains.• Equine-like G3P[8] strain is an emerging cause of gastroenteritis in Indonesia.