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PubMed2003

Rotavirus-specific B cells induced by recent infection in adults and children predominantly express the intestinal homing receptor alpha4beta7.

In vivo replication of rotaviruses is generally limited to enterocytes. Because of this restriction, most blood circulating rotavirus-specific B cells are hypothesized to originate in Peyer's patches and should express the intestinal homing receptor alpha4beta7. To test this hypothesis in humans, we used a flow cytometry assay that identifies antigen-activated (IgD-) B cells (CD19+) that express surface rotavirus-specific immunoglobulin. With this assay we could detect rotavirus-specific B cells in both children and adults with an acute rotavirus (RV) infection. Staining with an anti-alpha4beta7 monoclonal antibody, we could determine that B cells that express rotavirus-specific surface immunoglobulin predominantly express alpha4beta7. The response of rotavirus-specific antibody-secreting cells in the peripheral blood of children and adults with acute rotavirus infection was also studied by ELISPOT. The antibody-secreting cells of children were mainly of the IgM isotype, while the antibody-secreting cells of adults were predominantly of the IgA and IgG isotype. alpha4beta7+ and alpha4beta7- subsets of peripheral blood mononuclear cells were purified using paramagnetic beads and then tested in the ELISPOT assay. Rotavirus-specific antibody-secreting cells were predominantly present in the alpha4beta7+ subpopulation. The flow cytometry assay we have described will permit future studies to characterize the phenotype of virus-specific B cells and could be useful in the study of the immunogenicity and protective efficacy of RV vaccines and the identification of markers of protective immunity.

Adolescent↗
PubMed1996

Outbreaks of nosocomial rotavirus gastro-enteritis in a paediatric ward.

UNLABELLED: Faecal samples were collected from patients with gastro-enteritis during two winter seasons on a paediatric ward. Three outbreaks of nosocomial rotavirus gastro-enteritis were identified by latex agglutination and the virus strains were characterized by polyacrylamide gel electrophoresis of the genome nucleic acid and by subgrouping and serotyping enzyme-linked immunosorbent assays (ELISA). One outbreak was caused by serotype 1 rotavirus, one by serotype 2 and the remaining outbreak was caused by a mixture of serotypes 1 and 4. Identical electrophoretic patterns of the rotavirus genome in each outbreak combined with the ELISA results indicate that these three outbreaks were hospital-acquired cases. The index cases in the three outbreaks were community-acquired and one of two index cases in the second outbreak was hospital-acquired. On each occasion, susceptible roommates were easily infected from the index cases and then cross-infection occurred in the paediatric ward. Possible vehicles were the medical staff, especially doctors, parents of infected patients and infected patients who were moved to other rooms. One patient who had been treated with a series of antitumour therapies excreted rotaviruses in faeces for a long time period and probably played a role as a source of the outbreak. Moreover, some patients still excreted rotaviruses in their normal stool 1 week after recovery from gastro-enteritis. These findings indicate that continual examination of stool samples for rotaviruses until they are negative may be important to prevent the spread of rotavirus infection. CONCLUSION: Nucleic acid analysis and serotyping ELISA are useful tools for analyzing nosocomial rotavirus gastro-enteritis and important to prevent the spread of rotavirus infection in institutions.

Child↗
PubMed1993

Clinical trials of live oral rotavirus vaccines: the Finnish experience.

Live oral candidate rotavirus vaccines of bovine (RIT 4237) or rhesus (RRV-1) origin and reassortants of RRV-1 expressing human serotype 1 (DxRRV) or serotype 2 (DS1xRRV) VP7 protein were evaluated for clinical efficacy in young children in successive trials from 1983 to 1989. In each study, the vaccinations were given before a rotavirus epidemic season and the follow-up of vaccinees covered two rotavirus epidemic seasons lasting up to 2-3 years of age. Serotype 1 rotavirus was predominant in each season. Protection rates against all rotavirus-associated diarrhoea ranged from 0 to 67% but were higher, up to 100%, against more severe rotavirus disease. All tested vaccines also showed efficacy for diarrhoea not apparently associated with rotavirus; therefore the clinical benefit of the vaccinations was greater than could be deduced from efficacy rates for rotavirus-associated diarrhoea alone. Each of the candidate vaccines could significantly reduce severe diarrhoea in Finnish children in the first 2 to 3 years of life. For optimal efficacy, the vaccines should be administered in the autumn before the regular epidemic season of rotavirus.

Administration, Oral↗
PubMed1990

Evaluation of killed and modified live porcine rotavirus vaccines in cesarean derived colostrum deprived pigs.

Twenty-eight cesarean derived, colostrum deprived (CDCD) piglets were used to evaluate the efficacy of killed and modified live rotavirus (MLV) vaccines against challenge with virulent A-1 and A-2 rotaviruses. Two killed rotavirus vaccines were evaluated: an experimental vaccine and a commercially available vaccine. Efficacy parameters included: average daily weight gains, rotavirus shedding in feces, morbidity incidence and duration, and rotavirus serum antibody conversion post-vaccination and post-challenge. Piglets vaccinated orally/intramuscularly with the modified live vaccine were completely protected from A-1 and A-2 virulent rotavirus challenge. Nonvaccinated control piglets and piglets receiving killed rotavirus vaccines developed diarrhea, shed virus and exhibited reduced weight gains post-challenge. Only the MLV rotavirus vaccine was able to prevent virus shedding in feces after virulent challenge. Both controls and pigs which received killed vaccines intraperitoneally, orally or intramuscularly shed virus in the feces for 7 days post-challenge and virus peak titers approached 10(7) fluorescent antibody infectious dose (FAID)50/g feces. These studies clearly reflected the inability of killed rotavirus vaccines to induce active local immunity to rotaviral diarrhea in piglets.

Animals↗
PubMed1992

A study of the basis of virulence variation of bovine rotaviruses.

Rotaviruses are enteric pathogens of cattle but sub-clinical infections are common. Virulence variation has been identified with bovine rotaviruses and some rotaviruses replicated without clinical signs in non-immune calves. The rotavirus genome is composed of eleven segments of double-stranded RNA and the fourth largest segment codes for a non-glycosylated surface protein, VP4, which has been linked with virulence. In the present study the biological basis of rotavirus virulence variation was studied in vivo and compared with the known properties of the fourth gene. Calves were inoculated orally with a virulent rotavirus or a rotavirus of low virulence which multiplied but failed to cause diarrhoea. They were taken for necropsy at intervals of 2 days after inoculation. Clinical signs, virus in faeces and the percentage of infected small intestinal epithelium were determined. Damage to the small intestine was assessed by measurement of villus heights and crypt-cell production rates. Virulence was associated with a greater level of colonization of the small intestinal epithelium, greater enterocyte damage and preferential infection of the upper small intestine. The fourth gene determines the ability of rotaviruses to spread in vitro and the finding that virulence was associated with greater colonization in vivo raises the possibility that this gene may have an important role in rotavirus virulence.

Animals↗
PubMed2005

Experimental infection of non-human primates with a human rotavirus isolate.

Several rotavirus candidate vaccines have been developed and are at various stages of evaluation. In order to assess the safety and efficacy of these candidate vaccines, an appropriate non-human primate model is desirable. In earlier studies, we reported the presence of naturally occurring anti-rotavirus antibodies in monkeys and demonstrated that parenteral vaccination of baboons led to production of specific rotavirus antibodies in their milk. In the present study, we assessed the possibility of developing the baboon and the vervet monkey as an animal model for rotavirus studies by inoculating them with a pathogenic human rotavirus isolate prepared from the fresh faeces obtained from a child suffering from rotavirus diarrhoea. Preliminary studies have showed excretion of rotavirus in the faeces of 5 of 5 vervets monkeys and 1 of 2 baboons, by antigen ELISA and SDS-PAGE. These results were confirmed by RT-PCR and electron microscopy. The animals also showed elevation of IgG and high titres of virus neutralising antibodies. These data indicate that baboon and vervet monkeys may be useful models for human rotavirus infection and for pre-clinical evaluation of rotavirus candidate vaccines.

Animals↗
PubMed1992

Extraintestinal rotavirus infections in children with immunodeficiency.

Some rotavirus strains, including vaccine candidates, have been demonstrated to cause hepatitis in immunodeficient and malnourished mice and to grow in human liver cells. To determine whether rotavirus spreads outside the intestine in naturally infected children, we examined tissues from four immunodeficient children affected with severe combined immunodeficiency disease, acquired immunodeficiency disease syndrome, or DiGeorge syndrome. Chronic rotavirus-related diarrhea, which persisted until death, had also developed in each child. Using indirect immunoperoxidase techniques, we identified rotavirus antigen in the liver and kidney with a hyperimmune guinea pig antiserum prepared to double-shelled rotavirus particles. Similar immunostaining with an antiserum to a rotavirus nonstructural protein (NS26) provided evidence of active virus replication. The observed reactivity was eliminated specifically when serial sections were immunostained with the same antiserum that had been absorbed with either double-shelled rotavirus particles or NS26. Immunostaining was not observed in the liver of children with other diseases (alpha 1-antitrypsin deficiency, inspissated bile syndrome, and acute rejection of a transplanted liver). These findings demonstrate that rotavirus infections in children can extend beyond the intestinal tract. Further studies are warranted to determine whether extraintestinal rotavirus replication occurs in children without severe immunodeficiency, such as malnourished children.

Acquired Immunodeficiency Syndrome↗
PubMed1986

Protective effect of naturally acquired homotypic and heterotypic rotavirus antibodies.

To assess serotype specificity of immune resistance to rotavirus gastroenteritis, the relation between pre-existing neutralising antibodies to homotypic and heterotypic rotaviruses and protection against infection or clinical illness was investigated. The subjects were 44 orphans exposed once or twice to consecutive outbreaks of gastroenteritis due to type 3 rotavirus in an orphanage in Sapporo. Sera were collected throughout these outbreaks and the serum levels of neutralising antibodies against four different serotypes of group A human rotavirus were measured before and after the outbreaks. Protection against rotavirus gastroenteritis seemed to be serotype specific and to be related to levels of antibody against homotypic virus. A neutralising antibody level of 1/128 or greater seemed to be protective. The protective effect was of short duration, which was probably the explanation for recurrent attacks of gastroenteritis due to a rotavirus of the same serotype. Seroconversions or concomitant antibody responses to type 1 or 4 rotavirus in most children with type 3 rotavirus infection suggested that immunity to heterotypic virus can be induced by a rotavirus vaccine.

Antibodies, Heterophile↗
PubMed2002

Sequential analysis of nonstructural protein NSP4s derived from Group A avian rotaviruses.

We determined the NSP4 sequences of turkey rotavirus strains Ty-1 and Ty-3 and a chicken rotavirus, strain Ch-1, and compared these sequences with those of a pigeon rotavirus, strain PO-13, and mammalian rotaviruses. The turkey strains and PO-13 were found to be closely related (90-97% homologies). Ch-1 NSP4 was distinctly different from other avian rotavirus NSP4s, with 78-79% homologies. The NSP4 sequences of avian rotaviruses were found to be 6-7 amino acids shorter than those of all mammalian strains and to have considerably low identities (31-37%) with them. Therefore, it seems highly likely that the NSP4 genes of avian rotaviruses are classified into two NSP4 genotypes distinct from those of mammalian rotaviruses. The enterotoxin domain in NSP4 is conserved in terms of its sequential and structural properties despite extremely low homologies in the full lengths of NSP4s in avian and mammalian rotaviruses.

Amino Acid Sequence↗
PubMed2004

[Nosocomial gastroenteritis and asymptomatic rotavirus and astrovirus infection in hospitalized children].

BACKGROUND: Nosocomial gastroenteritis is frequent in pediatric hospital wards. Between 20% and 50% of gastroenteritis cases caused by rotavirus and astrovirus are of nosocomial origin. OBJECTIVE: To determine the incidence of nosocomial rotavirus and astrovirus gastroenteritis in our environment, the incidence of asymptomatic infection with these viruses, and to identify the G serotypes of the rotaviruses detected. METHODS: We performed a prospective study of all children under 2 years of age admitted to a neonatology unit over a 1-year period who were followed-up for the presence of diarrhea and periodic study of feces to detect the presence of rotavirus and astrovirus antigens by enzyme immunoassay (EIA). Patients with gastroenteritis also underwent bacteria stool culture, adenovirus detection by EIA, calcivirus detection by polymerase chain reaction, and analysis of rotavirus G serotypes by EIA with monoclonal antibodies. RESULTS: Of 666 children admitted without diarrhea, 60 presented nosocomial gastroenteritis (9 % of patients admitted and 1.75 per 100 days of hospital stay): 34 presented rotavirus (5 % of patients) and two presented astrovirus (0.3 % of patients). Of the 329 patients without diarrhea who were studied, viral elimination was detected in 27: rotavirus in 23 patients and astrovirus in four. Viral infection was detected on admission in 13 patients (4 %) and after 72 hours in 14 patients (4.2 %) (asymptomatic nosocomial infection). No differences in the distribution of rotavirus G serotypes were observed between community-acquired and nosocomial gastroenteritis. CONCLUSIONS: These data confirm the importance of viral etiology in nosocomial gastroenteritis and allow us to evaluate asymptomatic fecal elimination of rotavirus as one of the factors in the transmission of this infection.

Algorithms↗
PubMed2006

The paediatric burden of rotavirus disease in Europe.

Rotaviruses are a major cause of hospitalizations for acute gastroenteritis in developed countries. This review shows the burden of rotavirus disease in < 5-year-old children in Europe. An estimated 72,000-77,000 hospitalizations for community-acquired rotavirus disease occur annually in the 23 million under-fives living in the European Union (EU-25), with a median cost of Euro 1417 per case. Annual hospitalization incidence rates range from 0.3 to 11.9/1000 children < 5 years old (median 3/1000). The median proportion of hospital-acquired rotavirus disease among all cases of hospitalization for rotavirus disease is estimated to be 21%. Countries of the EU-25 require information on the burden of rotavirus disease to support introduction of rotavirus vaccines. Data on cases treated at home, medical visits, and emergency wards as well as rotavirus-associated deaths are limited. To fully evaluate the impact and effectiveness of rotavirus vaccination programmes in Europe, additional epidemiological studies will be critical and desirable.

Child, Preschool↗
PubMed2000

Serum antibody as a marker of protection against natural rotavirus infection and disease.

To determine whether naturally acquired serum IgA and IgG antibodies were associated with protection against rotavirus infection and illness, a cohort of 200 Mexican infants was monitored weekly for rotavirus excretion and diarrhea from birth to age 2 years. Serum samples collected during the first week after birth and every 4 months were tested for anti-rotavirus IgA and IgG. Children with an IgA titer >1:800 had a lower risk of rotavirus infection (adjusted relative risk [aRR], 0.21; P<.001) and diarrhea (aRR, 0. 16; P=.01) and were protected completely against moderate-to-severe diarrhea. However, children with an IgG titer >1:6400 were protected against rotavirus infection (aRR, 0.51; P<.001) but not against rotavirus diarrhea. Protective antibody titers were achieved after 2 consecutive symptomatic or asymptomatic rotavirus infections. These findings indicate that serum anti-rotavirus antibody, especially IgA, was a marker of protection against rotavirus infection and moderate-to-severe diarrhea.

Antibodies, Viral↗
PubMed2005

Estimates of the burden of rotavirus disease in Malaysia.

BACKGROUND: Accurate national estimates of the disease burden associated with rotavirus diarrhea are essential when considering implementation of a rotavirus vaccination program. We sought to estimate rotavirus disease-associated morbidity and mortality in Malaysia, using available sources of information. METHODS: We analyzed national data from the Ministry of Health (Kuala Lumpur, Malaysia) to derive rates of hospitalization, clinic visits, and deaths related to acute gastroenteritis (AG) among children <5 years of age. The number of events attributable to rotavirus infection was estimated by multiplying age-stratified rates of detection of rotavirus from 2 hospital surveillance sites by national data. RESULTS: In 1999 and 2000, an average of 13,936 children (1 in 187 children) were hospitalized annually for AG. Surveillance of visits to outpatient clinics for AG identified an average of 60,342 such visits/year between 1998 and 2000. The AG-associated mortality rate was 2.5 deaths/100,000 children. On the basis of the finding that 50% of children were hospitalized for rotavirus diarrhea, we estimated that 1 in 61 children will be hospitalized for rotavirus disease and that 1 in 37 children will seek treatment as an outpatient. CONCLUSIONS: Among Malaysian children, there is a significant burden associated with AG- and rotavirus disease-related hospitalizations and outpatient visits, and this burden potentially could be prevented by the use of rotavirus vaccines.

Child, Preschool↗
PubMed1993

Rotaviruses preferentially bind O-linked sialylglycoconjugates and sialomucins.

Rotaviruses are the most common cause of severe gastroenteritis in infants and children worldwide. Early events of virus binding and entry are the critical determinants of cellular permissiveness to rotavirus replication. The only known ligands for rotaviruses are sialic acids. We now report that simian rotaviruses bind preferentially to a subset of sialylated glycoconjugates, i.e. glycoproteins containing O-linked sialic acid moieties. Rotaviruses are able to distinguish between sialylated trisaccharide ligands presented as neoglycolipids. Higher avidity binding by rotaviruses is explained by multivalent binding to clustered sialic acid moieties. Our in vitro data are extended to explain the protective effect of mucins in the murine model of rotavirus disease and the specific binding by rotavirus to a high molecular weight sialomucin in the infant mouse intestine. Rotavirus binding to a sialomucin may be analogous to selectin-mediated mechanisms of cellular adhesion, and may be advantageous to the virus in the dynamic environment of the intestine.

Animals↗
PubMed1993

Rotavirus-specific humoral and cellular immune response after primary, symptomatic infection.

The humoral and cellular immune response after symptomatic, primary rotavirus infection was examined in 8 children < 2 years old. Rotavirus-specific IgA, rotavirus-specific helper T (Th) cells, and neutralizing antibody responses were evaluated at the time of illness, 2-8 weeks later, and 3-5 months later. In addition, rotavirus strains associated with infection were tested by polymerase chain reaction analysis using oligonucleotide primers specific for genes 4 (P type) and 9 (G type). The absence of rotavirus-specific IgA or rotavirus-specific helper T cell activity at the time of illness was consistent with a primary infection in 7 of 8 children. Two children were infected with serotype 1 (P type 1, G type 1), 3 with serotype 3 (P type 1, G type 3), and 3 with serotype 4 (P type 1, G type 4) strains. Neutralizing antibodies were directed against the gene 4 (P type) protein product (vp4). Because all infecting strains were P type 1, convalescent antisera did not distinguish among different rotavirus G types. Rotavirus-specific IgA responses were detected in 6 of 8 and rotavirus-specific Th cell responses in 7 of 8 children during convalescence.

Acute Disease↗
PubMed1996

The epidemiology of rotavirus diarrhea in the United States: surveillance and estimates of disease burden.

The decision to develop rotavirus vaccines was predicated on the extensive burden of rotavirus disease among children worldwide. US reports on nationwide hospitalizations (1979-1992) and deaths (1968-1991) due to diarrhea and weekly reports of rotavirus infection by 74 laboratories were reviewed to estimate the burden of rotavirus disease, identify epidemiologic trends, and consider methods for evaluating an immunization program when a vaccine becomes available. From 1968 to 1985, diarrhea-related deaths among US children <5 years old declined from 1100 to 300/year. This decline was associated with the disappearance of winter peaks for diarrhea-related deaths previously associated with rotavirus infection among children 4-23 months old. From 1979 to 1992, however, hospitalizations for diarrhea averaged 186,000/year and retained their winter peaks, which have been linked to rotavirus infections. Each year an estimated 54,000-55,000 US children are hospitalized for diarrhea, but <40 die with rotavirus. A rotavirus vaccine program will require improved surveillance, including the timely collection of data from sentinel hospitals, in which a diagnosis of rotavirus can be established or ruled out for all children hospitalized for diarrhea.

Child↗
PubMed1999

Ganglioside GM(1a) on the cell surface is involved in the infection by human rotavirus KUN and MO strains.

Rotavirus is the most common cause of severe gastroenteritis in infants and children worldwide. The cell attachment of most animal rotaviruses, which belong to the neuraminidase-sensitive strains, requires sialic acid residues on the host cell membranes. On the other hand, most human rotaviruses are classified as neuraminidase-insensitive strains. The involvement of gangliosides on the host cell surface in human rotavirus infection was investigated by immunostaining analysis of target cells, and by assaying the neutralization of infection by rotavirus and the blocking of target cellular receptors. In host cells (MA104 cells) pretreated with Arthrobacter ureafaciens neuraminidase, which were still infected by human rotaviruses (KUN and MO strains), GM(3) was hydrolyzed markedly by the neuraminidase, while GM(1a) was not hydrolyzed at all. Infection by the rotaviruses was strongly inhibited by exogenous ganglioside GM(1a), but not GA(1). Infection was also inhibited by pretreatment of the MA104 cells with cholera toxin B-subunit, which specifically blocked ganglioside GM(1a) on the plasma membrane. The treatment of MA104 cells with the endoglycoceramidase attenuated human rotavirus infection. From these findings, we concluded that GM(1a) on the plasma membrane of the host cells was involved in the infection by human rotavirus KUN and MO strains.

Animals↗
PubMed1995

Lactic acid bacteria in the treatment of acute rotavirus gastroenteritis.

We compared different lactic acid bacteria for their effect on the immune response to rotavirus in children with acute rotavirus gastroenteritis. After initial oral rehydration, 49 children aged 6 to 35 months with rotavirus gastroenteritis randomly received either Lactobacillus casei subsp. casei strain GG (LGG), L. casei subsp. rhamnosus (Lactophilus), or a combination of Streptococcus thermophilus and L. delbrückii subsp. bulgaricus (Yalacta) twice daily for 5 days. Serum antibodies to rotavirus, total number of immunoglobulin-secreting cells (ISC), and specific antibody-secreting cells (sASC) to rotavirus were measured at the acute stage and at convalescence. The mean (SD) duration of diarrhea was 1.8 (0.8) days in children who received LGG, 2.8 (1.2) days in those receiving Lactophilus, and 2.6 (1.4) days in those receiving Yalacta (F = 3.3, p = 0.04). The ISC response was comparable in the three study groups, but the rotavirus-specific immune responses were different. LGG therapy was associated with an enhancement of IgA sASC to rotavirus and serum IgA antibody level at convalescent stage. We conclude that certain strains of lactic acid bacteria, particularly LGG, promote serum and intestinal immune responses to rotavirus, and thus may be important in establishing immunity against rotavirus reinfections.

Acute Disease↗