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PubMed2004

First report from the Asian Rotavirus Surveillance Network.

Rotavirus remains the most common cause of severe, dehydrating diarrhea among children worldwide. Several rotavirus vaccines are under development. Decisions about new vaccine introduction will require reliable data on disease impact. The Asian Rotavirus Surveillance Network, begun in 2000 to facilitate collection of these data, is a regional collaboration of 36 hospitals in nine countries or areas that conduct surveillance for rotavirus hospitalizations using a uniform World Health Organization protocol. We summarize the Network's organization and experience from August 2001 through July 2002. During this period, 45% of acute diarrheal hospitalizations among children 0-5 years were attributable to rotavirus, higher than previous estimates. Rotavirus was detected in all sites year-round. This network is a novel, regional approach to surveillance for vaccine-preventable diseases. Such a network should provide increased visibility and advocacy, enable more efficient data collection, facilitate training, and serve as the paradigm for rotavirus surveillance activities in other regions.

Asia↗
PubMed1985

Risk factors associated with nosocomial rotavirus infection.

A prospective study of hospital-acquired rotavirus infection was undertaken on an infant and young toddler floor to assess the incidence of infection and risk factors associated with nosocomial transmission. During the seven-month study period, gastroenteritis accounted for 60 of 663 admissions, 23 (38%) of which were due to rotavirus. In spite of enteric isolation of 21 (91%) of 23 patients with community-acquired cases, 36 infants developed nosocomial rotavirus infections. The attack rate of hospital-acquired infection was 12.8%, ranging each month from 2% to 21%. Approximately three fourths of both community-acquired cases (17/23) and nosocomial cases (27/36) occurred during the late winter and early spring. Prolonged stays in the hospital were associated with an increased attack rate of rotavirus infection. The risk of nosocomial rotavirus infection was not significantly enhanced by room contact with a rotavirus-infected patient or by the sharing of staff. However, only 47% (17/36) of patients with nosocomial infections were appropriately isolated, despite symptoms of gastroenteritis in all cases. These findings indicate that hospital acquisition of rotavirus is common, and indicate that failure to isolate patients with nosocomial rotavirus infections could be an important factor in hospital transmission.

Child, Preschool↗
PubMed2001

Early events of rotavirus infection: the search for the receptor(s).

The entry of rotaviruses into epithelial cells seems to be a multistep process. Infection competition experiments have suggested that at least three different interactions between the virus and cell surface molecules take place during the early events of infection, and glycolipids as well as glycoproteins have been suggested to be primary attachment receptors for rotaviruses. The infectivity of some rotavirus strains depends on the presence of sialic acid on the cell surface, however, it has been shown that this interaction is not essential, and it has been suggested that there exists a neuraminidase-resistant cell surface molecule with which most rotaviruses interact. The comparative characterization of the sialic acid-dependent rotavirus strain RRV (G3P5[3]), its neuraminidase-resistant variant nar3, and the human rotavirus strain Wa (G1P1A[8]) has allowed us to show that alpha 2 beta 1 integrin is used by nar3 as its primary cell attachment site, and by RRV in a second interaction, subsequent to its initial contact with a sialic acid-containing cell receptor. We have also shown that integrin alpha V beta 3 is used by all three rotavirus strains as a co-receptor, subsequent to their initial attachment to the cell. We propose that the functional rotavirus receptor is a complex of several cell molecules most likely immersed in glycosphingolipid-enriched plasma membrane microdomains.

Animals↗
PubMed2001

Role for T cell-independent B cell activity in the resolution of primary rotavirus infection in mice.

We examined the importance of T cell-independent B cell activity in the resolution of primary murine (EDIM) rotavirus infection in adult mice. We showed that Rag 1 (C57BL / 6 background) and Rag 2 (BALB / c background) knockout mice, which lack both T and B cells, chronically shed high levels of rotavirus Ag in stool samples following oral inoculation. However, nude mice (BALB / c and C57BL / 6 backgrounds) and alpha beta TCR knockout mice (C57BL / 6 background) chronically shed 100-fold lower levels of virus in stool samples. Thus, B cells appeared to sharply reduce the level of chronic rotavirus shedding by a T cell-independent mechanism. C57BL / 6 mice depleted of CD4(+) cells or both CD4(+) and CD8(+) cells were also unable to resolve primary rotavirus infection but chronically shed equally low levels of rotavirus Ag in stool samples, whereas mice depleted of only CD8(+) cells resolved infection. Similar results were obtained with a second rotavirus strain (EC(w)) in which virus was shed chronically in stool samples at low levels in alpha beta TCR knockout mice and at high levels in Rag 1 knockout mice. Virus-specific intestinal IgA was readily detected in mice lacking thymic T cells and alpha beta T cells and in mice depleted of CD4(+) cells but levels were 95 % reduced in comparison to immunocompetent control mice. Together, these results show that B cells lacking CD4(+) T cell help have the capacity to substantially reduce rotavirus shedding, possibly through the production of T cell-independent IgA to rotavirus, but full resolution requires alpha beta T cells.

Animals↗
PubMed1992

Analysis of the genetic diversity of genes 5 and 6 among group C rotaviruses using cDNA probes.

Two partial cDNA clones of genes 5 (encoding the major inner capsid protein VP 6) and 6 (encoding a nonstructural protein) of the porcine group (Gp) C rotavirus (Cowden strain) were radiolabeled with 32P and used individually as probes in Northern and dot blot hybridization assays. The specificity of each probe was tested against genomic dsRNA from: (1) porcine Gp A, B, and C rotaviruses; (2) Gp C rotaviruses from different species; and (3) porcine Gp C rotavirus field strains with varying electropherotype patterns. Neither probe hybridized with ds RNA from the porcine Gp A and B strains under the stringency conditions employed in the study. However, the gene 5 probe hybridized with the corresponding gene from the homologous porcine and the heterologous human and bovine Gp C rotaviruses tested. The gene 6 probe hybridized with the corresponding gene from the homologous Cowden strain, but hybridized weakly with gene 6 from the human and bovine Gp C rotaviruses. Both probes recognized all six different porcine Gp C field strains, although with varying intensities. Our results demonstrate that the gene 5 and 6 probes used in this study are specific for Gp C rotaviruses. However, evidence for greater genetic variation in the gene 6 among porcine, bovine and human Gp C strains suggested that the gene 5 probe may prove more broadly reactive among Gp C strains from different species. cDNA probes used in our study should prove useful for the detection of Gp C rotaviruses in feces and facilitate epidemiologic studies.

Antigens, Viral↗
PubMed1991

HT-29 cells: a new substrate for rotavirus growth.

Susceptibilities of a continuous rhesus monkey kidney cell line (MA-104) and that of a human colon carcinoma cell line (HT-29) to infection by different human and animal rotavirus strains were compared. HT-29 cells appeared to be more sensitive to human rotavirus infection than MA-104 cells, whereas the latter cell line was more susceptible to animal rotavirus replication. The greater sensitivity to human rotavirus infection of HT-29 cells was confirmed by the successful, direct isolation of these viruses from faecal specimens. Human rotavirus infection of HT-29 cells was also followed by transmission electron microscopy. In ultra-thin sections, unenveloped particles of rotaviruses, representing infectious mature virions, were observed in large number. Moreover, many "double-shelled" particles were detected in negative-stained supernatants from infected cultures. Scanning electron microscopy of uninfected HT-29 cells showed that in the presence of Ca++, required for rotavirus growth, they are able to express some of the features of mature intestinal cells. In view of these results, HT-29 cells appear to be a useful in vitro model for the study of rotavirus infection.

Animals↗
PubMed1987

An equine rotavirus (FI-14 strain) which bears both subgroup I and subgroup II specificities on its VP6.

An equinine rotavirus FI-14 strain, originally isolated from a diarrheic foal in New York state, was shown to belong to serotype 3 by neutralization assay. In addition, it was found to react with both subgroup I and subgroup II monoclonal antibodies by enzyme-linked immunosorbent assay (ELISA), thus representing the first rotavirus strain to exhibit both subgroup specificities. By using hybridoma technology, we successfully produced monoclonal antibodies directed against the major inner capsid protein VP6 (the sixth gene product) of FI-14 virus. Such monoclonal antibodies reacted specifically with either subgroup I or subgroup II rotaviruses thus demonstrating that the VP6 of FI-14 virus has both subgroup I- and subgroup II-specific epitopes. Four additional monoclones directed to the VP6 of FI-14 demonstrated distinct reactivities by ELISA with a panel of 49 rotavirus strains derived from 11 different animal and avian species. Thus, at least six distinct antigenic sites were shown to exist on VP6 of FI-14 virus. When these 49 rotavirus strains were arranged based on their reactivity patterns with the six representative monoclones, they fell into one of eight reactivity groups. Analysis of the reactivity patterns of rotaviruses derived from various animal species suggested that human rotaviruses may have two ancestral lineages: one (subgroup II, serotype 1, 3, and 4) with pig-human lineage, and the other (subgroup I, serotype 2) with bovine-simian-human lineage. When analyzed by radioimmunoprecipitation, the molecular weight of the FI-14 virus VP6 (subgroups I and II) appeared to be larger (approx 45K) than those (approx 42K) of rhesus monkey MMU18006 virus VP6 (subgroup I) or human Wa virus VP6 (subgroup II). By RNA-RNA hybridization analysis, the FI-14 virus was shown not to share significant homology with viruses belonging to the four known human rotavirus serotypes.

Animals↗
PubMed1990

Neuroimmunomodulation of in vivo anti-rotavirus humoral immune response.

Neuropeptides and neurohormones (neurotransmitters) have been shown to modulate immune responses in vitro and in vivo. Since reproduction and lactation are regulated by neurohormones, we investigated whether neurohormones could enhance anti-rotavirus immunity in milk. Rotavirus-free mice were immunized orally with killed bovine rotavirus (BRV) and bred 6 weeks post-immunization. Post-whelping, each group of dams (ten mice/group) was given a single injection of prolactin (PRL), estrogen, PRL and estrogen or testosterone. The effects of neuropeptides, substance P (SP) and somatostatin (SS) on serum and lactogenic anti-rotavirus humoral immune responses were also investigated. The results revealed that in the groups given PRL or estrogen, anti-rotavirus antibody titers in milk and serum were enhanced. In contrast, testosterone had a negative effect on antibody titers. The administration of neuropeptide SP resulted in some enhancement of the lactogenic anti-rotavirus antibody titer at day 9 post-whelping whereas the opposite effect was observed following administration of SS. Prolactin given at 100 micrograms/mouse, on the day after whelping, gave optimum milk and serum antibody responses. Neurotransmitters potentiated immune responses to the weaker immunogenic proteins, VP4 and VP7 as well as to the strongly immunogenic VP6. In order to verify that the enhancement of anti-rotavirus antibody production was due to PRL and not to other factor(s), bromocriptine (BCR), a selective PRL inhibitor, was used as a control. Mice given BCR exhibited a drastic reduction in anti-rotavirus antibody in serum and milk. The role of neurotransmitters in the modulation of the lactogenic immune response and its significance in protection of neonates from enteric infections is discussed.

Animals↗
PubMed1989

Preparation and characterization of monoclonal antibodies to rotavirus.

By utilizing a strain of cultivable simian rotavirus (SA-11) as an immunizing antigen, we prepared 4 clones of mouse-mouse hybridoma, namely C127, C139, C172, and C214 which secreted monoclonal antibodies against the immunogen itself, SA-11 and also against other group A strains such as Wa and S2. Western blot analyses revealed that all of these antibodies are directed against VP6, a 42 kDa major inner capsid protein of group A rotavirus. Competitive experiments suggested that C127, C172 and C214 recognized three distinct epitopes on VP6, while C139 appeared to react with an epitope at or near the same epitope recognized by C172. We developed a two-step ELISA with excellent sensitivity and specificity for rotavirus detection by utilizing C127 and/or C214 as a capture antibody and rabbit anti-rotavirus conjugated with horseradish peroxidase as a probe. Also, when both monoclonal C127 capture antibody and polyclonal rabbit anti-rotavirus-HRP were incubated with rotavirus simultaneously in a one-step assay, equivalent sensitivity and specificity were observed. The data show that these generated anti-rotavirus antibodies can be utilized effectively as reagents for the detection of human rotaviruses in stool specimens.

Animals↗
PubMed1982

Interaction of rotavirus and enterotoxigenic Escherichia coli in conventionally-reared dairy calves.

A study was made of the effects of rotavirus and/or enterotoxigenic Escherichia coli (ETEC) on dairy calves born and suckled on the farm and subsequently reared in isolation. Calves were orally inoculated at 6 days old with either rotavirus (5), ETEC (7), rotavirus and ETEC (5) or remained uninoculated controls (4), and their reactions were recorded by clinical, microbiological, and pathological observations. Rotavirus infection consistently produced diarrhoea, while ETEC inoculated alone did not colonise the intestine. In dual infections, both rotavirus and ETEC multiplied, although the severity of diarrhoea was not greater than that caused by rotavirus alone. Some ETEC-inoculated calves developed subsequent naturally-acquired rotavirus infections, but in these no ETEC multiplication occurred. The results suggest that prior or simultaneous rotavirus infection is necessary to enable ETEC colonisation of the intestine in conventional calves of this age.

Animals↗
PubMed1989

Use of alkaline northern blot hybridization for the identification of genetic relatedness of the fourth gene of rotaviruses.

A recently developed alkaline northern blot hybridization assay (Li, J. K. K., Parker, B. & Kowalik, T., Analytical Biochemistry 163, 210-18, 1987) was used to assess the genetic relatedness of the fourth gene of human rotavirus strains recovered from children with diarrhea and from asymptomatic neonates. Genomic double stranded (ds) RNAs of the rotavirus strains were separated by polyacrylamide gel electrophoresis and were blotted to nylon membranes (Gene Screen Plus or Zeta Probe membranes). The blotted RNAs were then probed with 32P-labelled single-stranded (ss) RNA probes prepared by in vitro transcription from single-shelled particles of the different strains. When analysed under a condition of high stringency (52 degrees C, 2.5 x SSC, 50% formamide) that allowed up to 21% of nucleotide mismatch, a high degree of the fourth gene homology was observed among strains recovered from asymptomatic neonates (asymptomatic rotaviruses) or among strains recovered from infants and children with diarrhea (symptomatic rotaviruses), while the homology of the fourth gene between the asymptomatic and symptomatic strains was considerably lower. It is of particular interest that the fourth gene of the AU-1 and AU228 strains recovered from children with diarrhea failed to hybridize to the corresponding gene of either asymptomatic or symptomatic rotavirus strains but showed a high degree of homology with the fourth gene of a feline rotavirus recovered from an apparently healthy cat. These data indicate that a new group of the fourth gene is present among symptomatic rotaviruses and that the fourth gene of this group is genetically related to the corresponding gene of a feline rotavirus.

Animals↗
PubMed2005

[Morbidity and cost of rotavirus infections in France].

BACKGROUND: Rotavirus is the most common cause of severe diarrhea in children. Morbidity and mortality related to rotavirus infection is not well known in temperate countries in general, and in France in particular. OBJECTIVES: The aim of this study was estimate the morbidity, mortality, and cost related to the rotavirus infection in France, in order to assess the potential impact of a vaccination program. METHODS: A birth cohort was followed until 5 years of age using a decision tree model. Rotavirus infection incidence rates were modeled according to age, seasons, and breast-feeding status. RESULTS: Based on estimates from a decision model, we found that in France, rotavirus infection was responsible for 300,000 annual episodes of acute diarrhea, 138,000 visits to general practitioners, 18,000 hospitalizations, and 9 deaths. The annual direct cost related to rotavirus infection care was estimated at 28 million euros. CONCLUSION: This study demonstrates the high morbidity and cost of care associated with rotavirus infection in France. The decision tree model developed in this study could be used in the future to estimate the potential effectiveness, cost and cost-effectiveness of childhood vaccination strategies using new rotavirus vaccines.

Child, Preschool↗
PubMed2006

[Nosocomial rotavirus infections in a pediatric unit: surveillance during four successive winters].

UNLABELLED: The incidence of rotavirus and RSV outbreaks during winter seasons leads to overcrowding of pediatric units in the Paris area, and increases the risk of viral nosocomial infections in hospitalized young infants. OBJECTIVE: The aim of this study was to measure the incidence of rotavirus nosocomial infections in children less than 2 years of age during 4 consecutive winters. METHODS: All infants admitted in the pediatric unit during the winter were prospectively screened for rotavirus with a stools exam. All children with negative stools examination on admission but developing diarrhea after 2 days of hospitalization underwent a new screening test for rotavirus in stools. RESULTS: During the 4 consecutive winters, the global incidence of nosocomial rotavirus infection was 13.9% (12.7 to 15.9%). Asymptomatic carriage of rotavirus was detected in 3% of admitted infants. The risk of nosocomial rotavirus infection increases with young age and the length of hospital stay. CONCLUSION: The incidence of nosocomial rotavirus infections was high in this unit. It is related to overcrowding due to coincidence of diarrhea and bronchiolitis outbreaks in the Paris area and to the young age of hospitalized patients.

Age Factors↗
PubMed1998

Rotavirus infection of cultured intestinal epithelial cells induces secretion of CXC and CC chemokines.

BACKGROUND & AIMS: Rotaviruses are the major cause of pediatric gastroenteritis worldwide. The target cell of rotavirus infection is the mature enterocyte of the small intestine. Recently, intestinal epithelial cells have been shown to produce chemoattractant mediators in response to cytokine stimulation and bacterial infection, suggesting a potentially important role of epithelial cells in initiating immune responses. In this study, the production of chemokines by cultured intestinal epithelial cells after rotavirus infection was investigated. METHODS: Two human intestinal epithelial cell lines (HT29 and Caco-2) were infected with sucrose-purified rotavirus (strain SA114F) and assayed by reverse-transcription polymerase chain reaction and enzyme-linked immunosorbent assay for chemokine expression. Virus-like particles and inactivated rotavirus were used to test the importance of viral attachment and replication. RESULTS: Increased messenger RNA expression and secretion of immunoreactive interleukin 8, growth-related peptide alpha, and RANTES (regulated upon activation, normal T cell expressed and secreted) were detected in rotavirus-infected cells. Chemokine production was time and dose dependent and required viral replication. CONCLUSIONS: Rotavirus infection induces the expression of a subset of chemokines in intestinal epithelial cells. These data support the hypothesis that chemokine secretion by enterocytes may play a role in the initiation and modulation of the immune response to rotavirus infection.

Chemokine CCL5↗
PubMed2006

Rotavirus VP7, VP4 and VP6 genotypes co-circulating in Tehran, Iran, between 2003 and 2004.

Rotaviruses were detected by enzyme-linked immunosorbent assay (ELISA) in 92 out of 374 faecal samples collected between November 2003 and October 2004 at the Markaz Tebbi Koudakan Hospital, Tehran, Iran, from children aged 6 months to 5 years. Analysis of clinical and disease severity data showed a significant association between rotavirus infection and diarrhoea, vomiting and severe dehydration. Ninety-two samples (64 rotavirus ELISA-positive and 28 ELISA-negative samples) were sent to the Enteric Virus Unit, Virus Reference Department, Centre for Infection, Health Protection Agency, UK for rotavirus characterization by G-typing, P-typing and subgrouping (SG) using reverse transcriptase (RT)-PCR, semi-nested PCR and sequencing methods. In this study, both common and uncommon rotavirus genotypes were detected. The most prevalent types were G1P[8], SGII (59.2%) followed by G9P[8] SGII (15.5%) which has not been previously reported from Iran. Unusual genotypes G1P[10] SGI (2.8%) and G12P[8] SGII (1.4%) and strains derived from reassortment between common co-circulating genotypes such as G1P[4] SGII represented 5.6% of strains. Mixed infections with combinations of G1+G4P[8] SGII and G1+G9P[8] SGII were also found. This contrasts with previous reports from Iran in which a small number of common rotavirus strains (G1 and G4) were found. This study highlights the need for continued surveillance and characterization of rotaviruses to take account of the rapid evolution and introduction of novel rotaviruses into the human population.

Antigens, Viral↗
PubMed2000

Rotavirus outbreak on a pediatric oncology floor: possible association with toys.

BACKGROUND: Several outbreaks of rotavirus gastroenteritis have occurred in hospitals and day care centers. In the spring of 1997, an outbreak of rotavirus occurred on our pediatric unit. Aggressive infection control measures were instituted, and potential lapses in infection control were assessed. METHODS: Memorial Sloan-Kettering Cancer Center is a 434-bed cancer hospital in New York City. The pediatric unit is a 42-bed ward with both bone marrow transplant patients and non-bone marrow transplant oncology patients. Nosocomially acquired rotavirus was defined as diarrhea, vomiting, or gastrointestinal upset with onset 48 hours or more after hospital admission, accompanied by a positive enzyme immunoassay for rotavirus antigen. RESULTS: Between February 24 and April 4, 1997, 8 patients on the pediatric unit had nosocomial rotavirus. Aggressive infection control measures were instituted. Patients with rotavirus were cohorted and placed on contact precautions (strict handwashing, gloves, and gown). Investigation by the infection control team revealed that communal toys in the playroom were not being cleaned according to the weekly protocol. CONCLUSIONS: An outbreak of nosocomial rotavirus occurred on our pediatric oncology unit. Shared toys may have served as fomites in the transmission of rotavirus.

Cancer Care Facilities↗
PubMed2000

Integrin alpha(v)beta(3) mediates rotavirus cell entry.

Rotavirus strains differ in their need for sialic acid (SA) for initial binding to the cell surface; however, the existence of a postattachment cell receptor, common to most, if not all, rotavirus strains, has been proposed. In the present study, antibodies to the alpha(v) and beta(3) integrin subunits, and the alpha(v)beta(3) ligand, vitronectin, efficiently blocked the infectivity of the SA-dependent rhesus rotavirus RRV, its SA-independent variant nar3, and the neuraminidase-resistant human rotavirus strain Wa. Vitronectin and anti-beta(3) antibodies, however, did not block the binding of virus to cells, indicating that rotaviruses interact with alpha(v)beta(3) at a postbinding step, probably penetration. This interaction was shown to be independent of the tripeptide motif arginine-glycine-aspartic acid present in the natural ligands of this integrin. Transfection of CHO cells with alpha(v)beta(3) genes significantly increased their permissiveness to all three rotavirus strains, and the increment of virus infectivity was reverted by incubation of these cells either with antibodies to beta(3) or with vitronectin. These findings implicate alpha(v)beta(3) integrin as a cellular receptor common to neuraminidase-sensitive and neuraminidase-resistant rotaviruses, and support the hypothesis that this integrin could determine, at least in part, the cellular susceptibility to rotaviruses.

Animals↗
PubMed2005

Hospital-based study of the economic burden associated with rotavirus diarrhea in Hong Kong.

BACKGROUND: Rotavirus infection is the most common cause of severe diarrhea in both developed and developing countries. METHODS: To estimate the economic burden associated with rotavirus infection in Hong Kong, we combined data on the disease burden of rotavirus-associated hospital admissions with detailed cost data for a subsample of 471 children with diarrhea admitted to hospitals. RESULTS: The annual total social cost and total direct medical cost for rotavirus-associated admissions were calculated as 4.3 US dollars and 4 million US dollars, respectively, by use of data collected during March 2001 to March 2003. The estimate of the direct medical costs was approximately 4-fold higher than a previous estimate; this difference largely reflects the greater disease burden identified through active disease surveillance conducted under the auspices of the Asian Rotavirus Surveillance Network. On average, families spent 120 US dollars when their child's admission was associated with rotavirus infection; this cost represents approximately 10% of the monthly salary of an unskilled or service worker. CONCLUSIONS: These data emphasize the potential for a safe and effective rotavirus vaccine to reduce the economic burden associated with rotavirus disease.

Child, Preschool↗