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PubMed2004

Efficacy of RIX4414 live attenuated human rotavirus vaccine in Finnish infants.

BACKGROUND: Rotavirus gastroenteritis, a major cause of mortality and morbidity worldwide, is a vaccine-preventable disease. New safe and effective candidate rotavirus vaccines are needed to replace the withdrawn rhesus rotavirus-based oral vaccine. METHODS: We evaluated a monovalent human rotavirus vaccine, serotype G1, strain RIX4414, for efficacy, immunogenicity and safety in a randomized, double blind, placebo-controlled trial in Finland. We randomly allocated 405 healthy infants to receive 2 doses of vaccine or placebo (ratio 2:1) at approximately 2 and 4 months of age. The infants were followed during 2 rotavirus epidemic seasons (2000-2002) for acute gastroenteritis. Rotaviruses in diarrheal stool samples were primarily detected by enzyme-linked immunosorbent assay and confirmed and G-typed by reverse transciption-polymerase chain reaction. RESULTS: The vaccine was well-tolerated. No vaccine-related serious adverse events were observed during the study period. Rotavirus IgA (enzyme-linked immunosorbent assay) seroconversion rate was 80% after 2 doses. Thirty-eight cases of rotavirus gastroenteritis were detected during the entire follow-up period; 35 of these were of the G1 type. RIX4414 vaccine significantly decreased the occurrence of any rotavirus compared with placebo. Efficacy during the first rotavirus epidemic season was 73% [95% confidence interval (95% CI), 27-91%] and 90% (95% CI 10-100%) against any and severe rotavirus gastroenteritis, respectively, and during the entire follow-up period 72% (95% CI 42-87%) against any and 85% (95% CI 42-97%) against severe rotavirus gastroenteritis (P < 0.05 for all comparisons). CONCLUSIONS: RIX4414 strain of G1 human rotavirus vaccine was well-tolerated, immunogenic and efficacious in infants against rotavirus gastroenteritis during a 2-year period. To further increase vaccine "take" and efficacy, a higher dose of this vaccine may be considered for future efficacy trials.

Administration, Oral↗
PubMed1988

Passive immunity to bovine rotavirus infection associated with transfer of serum antibody into the intestinal lumen.

The effect of circulating passive antibody on immunity to bovine rotavirus infections in neonatal calves was investigated. In the first experiment, rotavirus antibody titers in the small intestinal lumina of 5- and 10-day-old calves with a wide range of serum rotavirus antibody titers were determined. Neutralizing antibody was present in the small intestinal lumina in titers that correlated with the calves' serum titers (r = +0.84, P less than 0.01). Immunoglobulin G1 was the predominant isotype of intestinal luminal rotavirus antibody. Calves not fed colostrum during the absorptive period lacked rotavirus antibody in circulation and in the intestinal lumen at 7 days of age, even when they were fed large volumes of colostrum with a high rotavirus antibody titer at 48 h after birth. Therefore, rotavirus antibody is not retained in the intestinal lumen for 5 days following a colostrum meal, and the luminal antibody in the 5- and 10-day-old seropositive calves were probably derived from circulating antibody. In a second experiment, calves were passively immunized by subcutaneous injection of colostral whey with a high immunoglobulin G1 rotavirus antibody titer and challenged with virulent bovine rotavirus 48 h later. The passively immunized calves were protected from rotavirus infection and diarrhea compared with calves with comparable serum immunoglobulin concentrations but with lower serum rotavirus with lower serum rotavirus antibody titers. The results of these experiments indicate that circulating immunoglobulin G1 antibody appears in the gastrointestinal tract of neonatal calves and that circulating rotavirus antibody can prevent infection and diarrhea after rotavirus challenge.

Animals↗
PubMed1999

Rotavirus vaccines: development and use for the prevention of diarrhoeal disease.

Rotavirus causes annually 600 000 deaths of young children worldwide, mainly in developing countries. The burden of rotavirus disease is significant also in developed countries and has not diminished with improved hygiene. Natural protective immunity against severe rotavirus disease is built up during the first 2-3 years of life. Likewise, studies with live attenuated oral rotavirus vaccines have shown that the majority of severe episodes of rotavirus diarrhoea are preventable by oral immunization. Candidate rotavirus vaccines were first developed by tissue culture adaptation and attenuation of bovine and rhesus rotaviruses, both of which share the inner core VP6 group antigen with human group A rotaviruses. Subsequently, such heterologous rotaviruses were improved for use as human vaccines by reassortment with human rotaviruses; the resulting reassortants express human rotavirus VP7 surface antigens. A rhesus-human reassortant tetravalent (RRV-TV) rotavirus vaccine was licensed in the USA in 1998, and is recommended for universal immunization of healthy children; licensure in Europe is also imminent. In Finland, this vaccine has prevented 90% of severe episodes of rotavirus gastroenteritis. Protective efficacy of RRV-TV vaccine in developing countries is lower and a more intensive immunization schedule may be needed. Several other candidate rotavirus vaccines, including bovine-human reassortants, are being investigated.

Animals↗
PubMed2002

[Cultivation and serial propagation of a new rotavirus causing adult diarrhea in primary human embryo kidney cells].

OBJECTIVE: To investigate the methodology of cultivation of the new rotavirus that causes adult diarrhea. METHODS: 10% suspension of new rotavirus positive stool specimens in DMEM with 100 microgram/ml trypsin was made and centrifuged at the speed of 3 000 rpm for 10 minutes. The supernatant was filtered with 0.45 micrometer-pore-sized membrane filter, and the filtrate was incubated at 37 degrees C for 60 minutes. Primary human embryo kidney (PHEK) cells were prepared and seeded into roller tubes at the concentration of 1 ml odf cell suspension per tube. At 1 hour prior to inoculation, the PHEK cells were rinsed and refed with serum-free DMEM. Immediately before inoculation, the DMEM was decanted, and 200 microliter of prepared filtrate was inoculated into each tube. The tubes were incubated at 37 degrees C for 1 hour. At the end of 1 hour 800 microliter of DMEM containing trypsin (100 microgram per ml) were added to each tube. The tubes were placed in a roller tube apparatus at 37 degrees C for 3 days, removed and frozen-thawed once. 200 microliter of the cell culture fluids (CCF) were used for inoculation of each tube for next virus passage. Detection of new rotavirus from CCF was carried out by PAGE, IF, EM and IEM. RESULTS: New rotavirus was successfully isolated in cultured cells from 1 of 10 specimens. The isolated virus, designated J19, was propagated in PHEK cells for 28 passages. RNA patterns of J19 strain were identical to that of original new rotavirus inoculum and different from that of group A, B, C rotavirus. PHEK cells infected with the J19 strain were detected by IF. Infected cells reacted with convalescent antisera to the new rotavirus, but did not react with convalescent antisera to ADRV and hyperimmune antisera against group A, B rotavirus. Rotavirus particles were detected by EM, IEM in infected CCF of J19 strain. Other viral particles were not observed. The particles were aggregated with convalescent antisera to new rotavirus. CONCLUSION: We were successful in adapting a new rotavirus to serial propagation in PHEK cells. The J19 strain is a kind of new rotavirus different from group A, B, C rotavirus. This is the first report on the cultivation and propagation of the new rotavirus in cultured cells.

Adult↗
PubMedDate not supplied

[Seroepidemiology of human rotaviruses in a community of the Avellaneda district, Province of Buenos Aires].

The results obtained during a prospective study performed in 49 families of the Avellaneda District, Buenos Aires Province, in order to known the seroepidemiology of human rotaviruses under natural conditions were described. Families which included a pregnant woman, were voluntarily recruited. The newborn was studied together with its family until two years of age, in order to assess the moment of the primary rotavirus infection. Feces from every person with gastrointestinal symptoms were obtained for rotavirus diagnosis. Blood samples from every member of the family were obtained since their recruitment and each 6 months until the newborn reached two years of age. Rotavirus infections were established by determining the amount of circulating rotavirus IgG antibodies in paired serum samples using ELISA. In all, 502.2 six-month periods with paired serum samples were studied. Most of the infections detected during the first year of life were primary infections (0.64 cases per child-year; 91.3% in seronegative children; p less than 0.005). The peaks of rotavirus diarrhea incidence were observed at the same age (0.25 cases per child-year; p less than 0.01). It must be stated that 51.9% of the newborns presented circulating anti-rotavirus IgG antibodies transmitted by the mother; 72% were breastfed for a mean period of 9.7 months. The total incidence of rotavirus infections was 0.63 cases per person-year, without significant variations for each age group. Most of them were asymptomatic cases and 61.6% were reinfections. These results show the high endemicity of human rotavirus in our population where siblings and adults act as reservoirs of the infection. Finally we found a significant relation between the level of circulating anti-rotavirus antibodies and the resistance to infection and illness caused by rotavirus during the six-month periods studied with paired serum samples (p less than 0.005 for infection; p less than 0.03 for diarrhea). The incidence of rotavirus infection did not seem to be statistically different among all the age groups. As we found a high incidence of reinfections and we were able to determine the total decrease in the level of serum anti-rotavirus IgG antibodies in 5% of the infections one year after the seroconversion was detected, we postulate a short duration of high antibody levels and protection associated with circulating anti-rotavirus antibodies.

Adult↗
PubMed2007

Efficacy, immunogenicity, and safety of a pentavalent human-bovine (WC3) reassortant rotavirus vaccine at the end of shelf life.

BACKGROUND: Rotavirus is the leading cause of dehydrating acute gastroenteritis in infants worldwide. Previous studies of a live pentavalent human-bovine reassortant rotavirus vaccine have shown it to be efficacious across a range of potencies. OBJECTIVE: Our goal was to evaluate the efficacy, immunogenicity, and safety of pentavalent rotavirus vaccine at the end of shelf life in healthy infants. PATIENTS AND METHODS: During 2002-2004, 1312 healthy infants approximately 6 to 12 weeks old from the United States (47%) and Finland (53%) were randomly assigned to receive 3 oral doses of vaccine (vaccine at approximately 1.1 x 10(7) infectious U per dose) or placebo approximately 4 to 10 weeks apart. Infants were to be followed for acute gastroenteritis through 1 rotavirus season after vaccination and for adverse events postvaccination. RESULTS: Three doses of pentavalent rotavirus vaccine at the end of shelf life demonstrated efficacy against rotavirus gastroenteritis caused by human G-serotypes included in the vaccine (G1-G4). Efficacy against severe rotavirus gastroenteritis was 100%, and efficacy against any rotavirus gastroenteritis regardless of severity was 72.5%. A threefold rise in G1 serum neutralizing was observed in 57% and in anti-rotavirus immunoglobulin A in 96% of pentavalent rotavirus vaccine recipients. No statistically significant increase in vomiting, diarrhea, or irritability was observed among pentavalent rotavirus vaccine recipients compared with placebo recipients within the 7-day period from each dose. A statistically significant increase in fevers (> or = 100.5 degrees F, rectal equivalent) was observed among pentavalent rotavirus vaccine recipients compared with placebo recipients after dose 1. CONCLUSIONS: This pentavalent human-bovine rotavirus vaccine was generally well tolerated, efficacious, and immunogenic at the end of shelf life.

Acute Disease↗
PubMed1986

Antibody response in serum and intestine in children up to six months after a naturally acquired rotavirus gastroenteritis.

The aim of this study was to provide detailed information about the local and systemic antibody response and their relationship following a rotavirus gastroenteritis. Rotavirus-specific immunoglobulins were analyzed by enzyme-linked immunosorbent assay (ELISA). The study included 49 children referred to hospital with rotavirus gastroenteritis and 16 children with nonrotavirus gastroenteritis. The concentrations of rotavirus immunoglobulin A (IgA) in serum increased within the first 2 weeks and those of rotavirus IgG within the first month after the onset of diarrhea. Thereafter, they remained unchanged during the 6-month observation period. Rotavirus ScIg (i.e., antirotavirus immunoglobulin-containing secretory component) appeared in serum almost exclusively within 7-14 days after onset (i.e., 85% of the samples). After the first 2 weeks, rotavirus IgA could be detected in the majority of fecal samples, even up to 6 months after the disease. However, rotavirus ScIg was absent in the majority of fecal samples. The severity of illness correlated only with the increase of rotavirus IgG in serum. Conclusively, there is a longstanding immune response after a naturally acquired rotavirus gastroenteritis. Moreover, with the present methods, measurements of rotavirus IgA and IgG in serum can be safely used for serodiagnosis, even when samples are taken with 6-month interval. It is suggested that trials with rotavirus vaccines include measurements of rotavirus IgA and ScIg in serum and rotavirus IgA in feces.

Adolescent↗
PubMed1999

Comparison of enzyme immunoassay and reverse transcriptase PCR for identification of serotype G9 rotaviruses.

While only four globally important rotavirus G serotypes (1 to 4) have been documented, many studies suggest that serotype G9 viruses may be widely distributed and more important than previously recognized. We have evaluated 10 serotype G9 rotavirus-neutralizing monoclonal antibodies (MAbs) directed to VP7, which bound by direct enzyme immunoassay (EIA) to P1A[8], G9 rotaviruses F45, WI61, and AU32, for their ability to recognize the New Delhi G9 rotavirus 116E. Only one MAb (MAb F45:1) bound to P[11], G9 virus 116E to a high titer by EIA. This MAb was incorporated into an indirect EIA for G serotyping, which was validated with prototype cultivable human rotaviruses of G types 1 to 4 and 9. The EIA was compared with genotyping by reverse transcriptase PCR (RT-PCR) under code for the determination of the G types of rotaviruses obtained from neonates in New Delhi, India. The sensitivities of RT-PCR and EIA (after two additional freeze-thaw cycles) for the typing of G9 rotaviruses were 91 and 86%, respectively, for 24 culture-adapted rotavirus strains. The untypeable culture-adapted rotavirus samples also were unreactive with VP7 group antigen-reactive MAb 60. After two additional freeze-thaw cycles, only 26 of 42 (62%) of stools containing rotavirus typed as G9 by RT-PCR were positive for G9 rotavirus by EIA. Stools containing rotavirus untypeable by EIA contained significantly less MAb 60-reactive VP7 antigen (P = 0. 0001) than the stools containing typeable rotavirus. Thus, RT-PCR genotyping was the more sensitive method for determination of G9 type, but a serotype was readily determined in rotavirus samples containing MAb 60-reactive VP7 antigen by an EIA that incorporates MAb F45:1.

Antibodies, Monoclonal↗
PubMed1998

Analysis of host range restriction determinants in the rabbit model: comparison of homologous and heterologous rotavirus infections.

The main limitation of both the rabbit and mouse models of rotavirus infection is that human rotavirus (HRV) strains do not replicate efficiently in either animal. The identification of individual genes necessary for conferring replication competence in a heterologous host is important to an understanding of the host range restriction of rotavirus infections. We recently reported the identification of the P type of the spike protein VP4 of four lapine rotavirus strains as being P[14]. To determine whether VP4 is involved in host range restriction in rabbits, we evaluated infection in rotavirus antibody-free rabbits inoculated orally with two P[14] HRVs, PA169 (G6) and HAL1166 (G8), and with several other HRV strains and animal rotavirus strains of different P and G types. We also evaluated whether the parental rhesus rotavirus (RRV) (P5B[3], G3) and the derived RRV-HRV reassortant candidate vaccine strains RRV x D (G1), RRV x DS-1 (G2), and RRV x ST3 (G4) would productively infect rabbits. Based on virus shedding, limited replication was observed with the P[14] HRV strains and with the SA11 Cl3 (P[2], G3) and SA11 4F (P6[1], G3) animal rotavirus strains, compared to the homologous ALA strain (P[14], G3). However, even limited infection provided complete protection from rotavirus infection when rabbits were challenged orally 28 days postinoculation (DPI) with 10(3) 50% infective doses of ALA rabbit rotavirus. Other HRVs did not productively infect rabbits and provided no significant protection from challenge, in spite of occasional seroconversion. Simian RRV replicated as efficiently as lapine ALA rotavirus in rabbits and provided complete protection from ALA challenge. Live attenuated RRV reassortant vaccine strains resulted in no, limited, or productive infection of rabbits, but all rabbits were completely protected from heterotypic ALA challenge. The altered replication efficiency of the reassortants in rabbits suggests a role for VP7 in host range restriction. Also, our results suggest that VP4 may be involved in, but is not exclusively responsible for, host range restriction in the rabbit model. The replication efficiency of rotavirus in rabbits also is not controlled by the product of gene 5 (NSP1) alone, since a reassortant rotavirus with ALA gene 5 and all other genes from SA11 was more severely replication restricted than either parental rotavirus strain.

Animals↗
PubMed2001

Differential infection of polarized epithelial cell lines by sialic acid-dependent and sialic acid-independent rotavirus strains.

Infection of epithelial cells by some animal rotaviruses, but not human or most animal rotaviruses, requires the presence of N-acetylneuraminic (sialic) acid (SA) on the cell surface for efficient infectivity. To further understand how rotaviruses enter susceptible cells, six different polarized epithelial cell lines, grown on permeable filter membrane supports containing 0.4-microm pores, were infected apically or basolaterally with SA-independent or SA-dependent rotaviruses. SA-independent rotaviruses applied apically or basolaterally were capable of efficiently infecting both sides of the epithelium of all six polarized cell lines tested, while SA-dependent rotaviruses only infected efficiently through the apical surface of five of the polarized cell lines tested. Regardless of the route of virus entry, SA-dependent and SA-independent rotaviruses were released almost exclusively from the apical domain of the plasma membrane of polarized cells before monolayer disruption or cell lysis. The transepithelial electrical resistance (TER) of cells decreased at the same time, irrespective of whether infection with SA-independent rotaviruses occurred apically or basolaterally. The TER of cells infected apically with SA-dependent rotaviruses decreased earlier than that of cells infected basolaterally. Rotavirus infection decreased TER before the appearance of cytopathic effect and cell death and resulted in an increase in the paracellular permeability to [(3)H]inulin as a function of loss of TER. The presence of SA residues on either the apical or basolateral side was determined using a Texas Red-conjugated lectin, wheat germ agglutinin (WGA), which binds SA residues. WGA bound exclusively to SA residues on the apical surface of the cells, confirming the requirement for SA residues on the apical cell membrane for efficient infectivity of SA-dependent rotaviruses. These results indicate that the rotavirus SA-independent cellular receptor is present on both sides of the epithelium, but SA-dependent and SA-independent rotavirus strains infect polarized epithelial cells by different mechanisms, which may be relevant for pathogenesis and selection of vaccine strains. Finally, rotavirus-induced alterations of the epithelial barrier and paracellular permeability suggest that common mechanisms of pathogenesis may exist between viral and bacterial pathogens of the intestinal tract.

Animals↗
PubMed2006

Diarrhea- and rotavirus-associated hospitalizations among children less than 5 years of age: United States, 1997 and 2000.

OBJECTIVE: A new rotavirus vaccine may be licensed in the United States in early 2006. Estimates of the burden of severe rotavirus disease, particularly hospitalizations, will help evaluate the potential benefits of a national rotavirus immunization program. DESIGN: The Kids' Inpatient Database, a robust sample of 10% of the uncomplicated births and 80% of other pediatric discharges was used to estimate the number and rate of diarrhea- and rotavirus-associated hospitalizations among US children <5 years of age in 1997 and 2000. RESULTS: In 1997 and 2000, diarrhea was coded in 13% of all childhood hospitalizations, for an estimated cumulative incidence of 1 diarrhea hospitalization per 23 to 27 children by age 5. Most diarrhea-associated hospitalizations (62%) were coded as unspecified etiology, and 35% as viral. Rotavirus was the most common pathogen recorded for 18% and 19% of diarrhea-associated hospitalizations in 1997 and 2000, respectively. Diarrhea-associated hospitalizations coded as unspecified or viral exhibited a marked winter peak similar to that of hospitalizations coded as rotavirus, suggesting that the rotavirus-specific code captures a fraction of all rotavirus hospitalizations. Using indirect methods, we estimated that rotavirus was associated with 51142-60155 and 46839-56820 hospitalizations in 1997 and 2000, respectively. By these estimates, rotavirus is associated with 4% to 5% of all childhood hospitalizations, and 1 in 67 to 1 in 85 children will be hospitalized with rotavirus by 5 years of age. CONCLUSIONS: Diarrhea is an important cause of hospitalization in US children, and rotavirus is the most important etiology. Disease burden estimates have remained stable during the past decade. An effective rotavirus vaccine will likely reduce substantially the burden of severe rotavirus disease, estimated to account for 4% to 5% of all hospitalizations and approximately 30% of hospitalizations for watery diarrhea among children <5 years of age.

Child, Preschool↗
PubMed1999

[Rotavirus: clinical features and prevention]

OBJECTIVES: This report was prepared with the main objective of making an extensive review of both clinical features and prevention of rotavirus gastroenteritis. In addition, it provides an evaluation about the potential for introduction of the tetravalent rhesus-human reassortant rotavirus vaccine (RRV-TV) in the developing countries. METHODS: The main source of information was the most relevant articles published in both national and international journals, as well as selected official reports from the World Health Organization. With regard to rotavirus vaccines, particular emphasis has been placed on the results available from studies carried out during the past five years. Notice we have stressed the epidemiological features of rotavirus infections in Brazil. RESULTS: As a background for the main subjects of this report - clinical features and prevention - available general information on rotavirus infections are briefly discussed in the Introduction. This includes an overview of the etiological agent, epidemiology, immunity and laboratory diagnosis. A detailed description of the typical symptomatic syndrome is made, as well as of other (unusual) clinical manifestations of rotavirus illness. We also discuss the rotavirus candidate vaccines that have been evaluated to date, highlighting the most significant observations which resulted from field trials with the RRV-TV in several countries. The potential for large-scale use of RRV-TV in developing countries is also discussed, focusing mainly on the epidemiological characteristics of rotavirus disease in these regions. CONCLUSION: Rotaviruses are the leading cause of severe gastroenteritis in infants and young children in both industrialized and lessdeveloped countries; in the latter regions, rotavirus diarrhoeal disease represents a major cause of mortality. There is currently a consensus that attempts at prevention need to be directed toward the development of an effective rotavirus vaccine, for large-scale use, that would primarily protect children (aged 0 to 2 years) against severe rotavirus gastroenteritis. In this regard, results from a recent reevaluation of the Peruvian and Brazilian lower-titer RRV-TV efficacy data are promising. Although the RRV-TV ("Rotashield(R)") (recently licensed for general use in U.S.A.) seems to be currently the most promising rotavirus vaccine, it has been suggested that further trials with this vaccine should be conducted in Africa and Asia (efficacy studies) and Latin America [immunogenicity and effectiveness (efficacy under real conditions in a given setting)]. In addition, it is of paramount importance to establish in these regions a surveillance system to monitor the circulating rotavirus strains.

Journal Article↗
PubMed1987

Clinical trials of rotavirus vaccines.

The clinical efficacy of candidate rotavirus vaccines has been tested in Tampere, Finland, over four winter and spring rotavirus epidemic seasons in 1983-1986. Testing against natural challenge has demonstrated that heterologous oral rotavirus vaccines induce cross-protection to human rotavirus diarrhoea. The trials have also given insight into mechanisms of protection in human rotavirus diarrhoea. After the oral vaccination of infants aged six to 12 months the highly attenuated bovine rotavirus strain RIT 4237, titre 10(8) per dose, probably 'takes' in most vaccinees, producing a symptomless intestinal infection with a low virus excretion rate and an antibody response in over 80% of the initially seronegative subjects. Upon natural challenge such vaccination gives no protection against human rotavirus infection but gives 50-60% protection against any clinically detectable rotavirus-associated illness and 80-90% protection against severe rotavirus diarrhoea, regardless of the infecting human rotavirus serotype. The less attenuated rhesus monkey rotavirus RRV-1, titre 10(5)-10(6) per dose, is more infectious in humans, and virus multiplication in the intestine results in excretion of vaccine virus in the stools and some clinical symptoms, mainly fever, 3-4 days after vaccination. The degree of protection against human rotavirus diarrhoea appears similar to that induced by bovine rotavirus vaccine.

Antibodies, Viral↗
PubMed1987

Novel rotaviruses in animals and man.

Novel (non-group A) rotaviruses have many of the morphological, biochemical and biological properties described originally for group A rotaviruses but they do not share the same group antigens. By negative-stain electron microscopy, novel rotaviruses have the characteristic rotavirus morphology, although with some novel rotaviruses the characteristic single- and double-shelled particles may not be readily apparent. Comparison of novel rotaviruses in serological tests has revealed the existence of at least six rotavirus serogroups, A to F, with the original rotaviruses belonging to group A. As with group A rotaviruses, viruses from different animal species, including man, can belong to the same serogroup. A further point of difference between novel and group A rotaviruses is their genome profiles, which lack the triplet of segments in the 7-8-9 region of group A rotaviruses. This is a useful diagnostic aid. Novel rotaviruses have been found in farm animals and man. They can cause enteritis experimentally and infect villus enterocytes. In chickens, turkeys, lambs and pigs the viruses and/or antibody to them are commonly found, in association with either clinical or subclinical infection. In humans one type of novel virus has emerged as a cause of severe diarrhoeal disease in adults. The possible reasons for the relatively recent discovery of the novel rotaviruses are discussed.

Animals↗
PubMed2003

Isolation, serologic and molecular characterization of the first G3 caprine rotavirus.

We isolated a rotavirus in cell culture, named the GRV strain, from a stool specimen of a Korean goat with diarrhea, and performed an in-depth characterization. At various passage levels in cell culture, the GRV strain retained its pathogenicity for goat kids, thereby for the first time establishing that a caprine rotavirus can cause diarrhea in goat kids. The GRV strain grew to a high titer and agglutinated group O human erythrocytes. The GRV VP7 protein was 96% identical with the RRV (simian rotavirus) and R2 (lapine rotavirus) VP7 proteins, and slightly less similar to the SA11 (simian rotavirus) and HCR3 (feline/canine-like human rotavirus) VP7 proteins. The GRV VP4 protein was 93% identical with the RRV VP4 (P[3]) and 90% identical with the SA11 VP4 (P[2]). However, phylogenetic analysis including more VP4 sequences from representative P[3] strains unambiguously placed the GRV VP4 in the cluster of P[3] VP4s. A high level of two-way cross neutralization with RRV substantiated that GRV was a G3P5[3] strain, thus identifying GRV as the first caprine rotavirus with such a phenotype. The GRV NSP4 sequence belonged to the AU-1 allele, as does the RRV NSP4 sequence. Genetic analysis by RNA-RNA hybridization revealed that the overall genomic RNA constellation of the GRV strain was unique among mammalian rotavirus genogroups and that it was almost equally related to, yet distant from, simian rotavirus RRV, feline/canine rotavirus FRV64 (or CU-1), feline/human rotavirus FRV-1 (or AU-1), and lapine rotavirus R2. The availability of the GRV strain will further expand our limited knowledge of caprine rotaviruses.

Alleles↗
PubMed2003

Rotavirus detection and characterisation in outbreaks of gastroenteritis in aged-care facilities.

BACKGROUND: Although rotavirus is a major cause of gastroenteritis in children, its role in adult gastroenteritis and the sensitivity of different methods for its detection in specimens collected from adults are less well understood. OBJECTIVES: (1) To examine the frequency and seasonality of rotavirus-associated gastroenteritis outbreaks in aged-care facilities in Victoria, Australia. (2) To determine rotavirus type in these outbreaks. (3) To determine whether other enteropathogenic agents are present in specimens from these outbreaks. (4) To examine the sensitivity of different methods (electron microscopy (EM), reverse transcription-polymerase chain reaction (RT-PCR), enzyme immunoassay (EIA) and latex agglutination (LA)) for the detection of rotavirus in specimens from adults. STUDY DESIGN: Specimens from gastroenteritis outbreaks in aged-care facilities forwarded to this laboratory for the years 1997-2000 were tested for enteropathogenic agents by various methods. Epidemiological, clinical and seasonal data from the rotavirus-positive outbreaks were analysed. RESULTS: Rotavirus was detected by EM in 18 out of 29 individuals associated with seven out of 53 (13%) gastroenteritis outbreaks in aged-care facilities; norovirus was detected in 22 outbreaks (42%) and astrovirus in one outbreak (2%). No mixed viral infection was found in any outbreak. All rotaviruses were typed as Group A by RT-PCR. The rotaviruses in the seven outbreaks were G-typed as follows: G2 (three outbreaks), G4 (two outbreaks), G1 (one outbreak) and G9 (one outbreak). The rotavirus-associated outbreaks were concentrated in mid-winter to mid-spring. The relative sensitivities of the Group A rotavirus detection methods (for the 29 specimens tested) were EM (18), first-round RT-PCR (11), second-round PCR (19), EIA-visual (19), EIA-photometric (19) and LA (13). CONCLUSIONS: In Victoria, Australia, outbreaks of gastroenteritis associated with rotavirus are quite common in aged-care facilities. They involve Group A rotavirus and have a winter/spring seasonality. G-types G1, G2, G4 and G9 were all detected. EIA, second-round PCR and EM proved sensitive methods for rotavirus detection whereas first-round RT-PCR and LA did not.

Aged↗
PubMed1997

Rotavirus infections in young Nicaraguan children.

BACKGROUND: Rotavirus is an important cause of dehydrating diarrhea in young children throughout the world. Knowledge about frequency of reinfections, development of immunity to the virus and the possible protective effect of breast milk is important, in particular in relation to possible strategies for immunization. METHODS: A prospective study of rotavirus infections in a cohort of 235 infants followed from birth until 2 years of age was performed in León, Nicaragua. Fecal and serum specimens were collected at specified times, and stools were also obtained during episodes of diarrhea. Fecal specimens were screened by rotavirus antigen detection and serum and colostral specimens were analyzed by isotype-specific rotavirus antibody enzyme-linked immunosorbent assay. RESULTS: As judged by anti-rotavirus IgA antibody seroconversion and/or demonstration of rotavirus antigen in fecal specimens, > 50% of the babies had evidence of past rotavirus infection by the age of 2 months. The total incidence of rotavirus infections, including many reinfections, was 0.7 infection/child-year, of which only 17% were associated with diarrhea. The time from birth to the first demonstration of rotavirus in stool samples correlated significantly with the concentration of anti-rotavirus IgA antibodies in colostrum. There was also a tendency toward a relationship between long duration of breast-feeding and asymptomatic infection. CONCLUSIONS: Rotavirus infections are acquired very early in infants in León, Nicaragua, and reinfections are common. Most infections are asymptomatic. Breast milk appears to confer partial protection against rotavirus infection, probably mediated by specific IgA antibodies. To be effective rotavirus vaccination would probably have to be given at a very early age to infants in developing countries.

Antibodies, Viral↗
PubMed2004

Rotavirus-specific T-cell responses in young prospectively followed-up children.

Rotavirus is a major cause of gastroenteritis in young children. Antibodies seem to protect against rotavirus infection but cell-mediated immune responses are probably also important for protection. We evaluated the development of T-cell responses to rotavirus in follow-up samples from 20 healthy children with an increased genetic risk for type 1 diabetes. Blood samples from 16 healthy adults were also available for the study. T-cell proliferation was analysed at 3-6 month intervals from the age of 3 months to the age of 4-5 years using the Wa strain of human rotavirus and the NCDV strain of bovine rotavirus as antigens. IgG and IgA antibodies to rotavirus were studied from simultaneously drawn plasma samples with EIA method using NCDV as an antigen. A total of 24 infections were revealed by antibody analysis. Sixteen children showed diagnostic increases in both IgG and IgA antibodies to rotavirus, while 5 children showed increases in IgA antibodies only and 3 in IgG only. Antibody rises were accompanied by T-cell responses to rotavirus (SI > 3) in 9 of the 24 cases. T-cell responses to purified or lysed human rotavirus were stronger after a rise in rotavirus antibodies than the responses before infection (P = 0.017 and 0.027, respectively). There was a correlation between T-cell responses to purified and lysed human rotavirus and NCDV. Strong T-cell responses to rotavirus were transient and the ability to respond usually disappeared in one year, but in all adults T-cell responses to rotavirus were strong implicating that several infections are needed to develop consistent, strong T-cell responsiveness.

Adult↗