A high-Mr glycoprotein fraction from cow's milk potent in inhibiting replication of human rotavirus in vitro. (1/1527)

Rotavirus is the major cause of infectious diarrhea in infants and young children all over the world. We have found that a high-M(r) glycoprotein fraction from cow's milk is potent in inhibiting replication of human rotaviruses in vitro. Since the activity seems to be unique and specific, this fraction may be useful as a novel agent for treatment or prevention of rotavirus diarrhea.  (+info)

Rotavirus G-type restriction, persistence, and herd type specificity in Swedish cattle herds. (2/1527)

G-typing of rotavirus strains enables the study of molecular epidemiology and gathering of information to promote disease prevention and control. Rotavirus strains in fecal specimens from neonatal calves in Swedish cattle herds were therefore characterized by using G1 to -4-, G6-, G8-, and G10-specific primers in reverse transcription (RT)-PCR. Fecal samples were collected from one dairy herd (herd A) for 4 consecutive years and from 41 beef and dairy herds (herd B) experiencing calf diarrhea outbreaks. Altogether, 1, 700 samples were analyzed by group A rotavirus enzyme-linked immunosorbent assay, and 98 rotavirus-positive specimens were selected for G-typing by RT-PCR. The effect of herd type, time, geographic region, and clinical symptoms on the G-type distribution was evaluated. Altogether (herds A and B), G10 was found in 59 (60. 2%) fecal specimens, G6 was found in 30 (30.6%) specimens, G3 was found in 1 (1.0%) specimen, and G8 was found in 1 (1.0%) specimen. Seven (7.1%) fecal specimens were not typeable. Herd type specificity in the G-type distribution was demonstrated in the herds in herd B. In the 6 beef suckler herds, only G6 was detected, while rotavirus strains from the 35 dairy herds were predominantly (54%) G10. The G-type distribution was restricted in herds A and B. Twenty-nine of 30 strains from herd A were characterized as G10. In the vast majority of herds in herd B, a single G-type was identified. The serotype G10 and the electropherotype persisted over time in herd A. No characteristic G-type variation in the geographic distribution of cattle herds in herd B was obvious. There was no difference in the G-type distributions between the strains from clinically and subclinically rotavirus-infected calves in dairy herd A. The results from this study strongly indicate a pronounced stability in the rotavirus G-type distribution in Swedish cattle herds, which emphasizes the importance of continuous preventive measures for control of neonatal calf diarrhea. A future bovine rotavirus vaccine in Sweden should contain G10 and G6 strains.  (+info)

Isolation of a human rotavirus strain with a super-short RNA pattern and a new P2 subtype. (3/1527)

Super-short rotavirus strains that have a rearranged gene segment 11 are rarely found in humans, and only five isolates, all from Southeast Asia, have been described in the literature. We report the first isolation in Japan from an infant with severe diarrhea of a rotavirus possessing a super-short RNA pattern. This strain, designated AU19, had a G1 VP7 and is also the first isolate in Japan that possesses a P2[6] VP4. Furthermore, the P2[6] VP4 carried by AU19 was divergent in the hypervariable region of the amino acid sequence from the P2A[6] VP4s carried by asymptomatic neonatal strains or from the P2B[6] VP4 carried by porcine rotavirus strain Gottfried. Thus, AU19 is likely to represent a new VP4 subtype, which we propose to call P2C. Given the recent emergence of the P2[6] VP4s in India, Brazil, and the United States and the role of VP4 in protective immunity, further scrutiny is justified to see whether the emergence of the previously underrepresented P2[6] VP4 serotype is related to this new P2 subtype.  (+info)

Genetic and antigenic characterization of a serotype P[6]G9 human rotavirus strain isolated in the United States. (4/1527)

During an epidemiologic survey of rotavirus infections established to monitor the prevalent G serotypes circulating in the United States, human P[6]G9, subgroup I rotavirus strains causing symptomatic infections were identified as the fourth most common serotype. In this report we describe the molecular and antigenic characterization of one of these P[6]G9 isolates (US1205). Neutralization and sequencing studies have demonstrated that both outer capsid proteins, VP7 and VP4, of US1205 are closely related to but genetically and antigenically distinguishable from those of standard G9 strains (e.g., F45, WI61) and standard P2A[6] strains (e. g., ST3, M37). Thus the complete antigenic type of US1205 is P2A[6]G9, subgroup I. Sequence analysis of the VP6 and NSP4 genes of US1205 indicates that strain US1205 possessed VP6 subgroup I and NSP4A genotype specificities. Finally, Northern hybridization studies suggest that the P[6]G9 strains are closely related to members of the DS-1 genogroup except for their P[6] VP4 gene, which has been commonly identified in strains of both major human genogroups, and their G9 VP7 gene, which may have been derived by reassortment with a Wa genogroup strain. Examination of historic collections and prospective surveillance of strains will be needed to determine whether this strain has been present for some time or if it is emerging to compete with the other common serotypes of rotavirus.  (+info)

Immunity to rotavirus infection in mice. (5/1527)

Recent findings from our laboratory regarding the immune response of mice to rotavirus (a mucosal pathogen) show that although in most situations an acquired (T or B cell or both) response is necessary for elimination of primary rotavirus infection, unidentified innate mechanisms can also play a role in some mouse strains. Similar to what is seen with many other viruses, CD8+ T cells appear to provide the first but not the exclusive mechanism that mediates clearance of a primary rotavirus infection. Antibodies are the critical mediators of prevention against rotavirus reinfection. Nonneutralizing IgA monoclonal antibodies directed against VP6 (an internal structural rotavirus protein) can mediate immunity against rotaviruses in vivo. Rotavirus-specific CD8+ T cells can mediate their antiviral effect in the absence of perforin, fas, or interferon-gamma and are preferentially represented in the subset that expresses high levels of the enteric mucosal homing receptor alpha4beta7.  (+info)

Enteropathogens and other factors associated with severe disease in children with acute watery diarrhea in Lima, Peru. (6/1527)

To evaluate enteropathogens and other factors associated with severe disease in children with diarrhea, 381 children <5 years of age with diarrhea and moderate to severe dehydration (in-patients) and 381 age-, sex-, and date-of-visit-matched children with mild diarrhea (out-patients) presenting to a hospital in Peru, were studied. Rotavirus was detected in 52% of the in-patients and 35% of the out-patients (odds ratio [OR]=2.3, 95% confidence interval [95% CI]= 1.6-3.2); 95% of the rotaviruses among in-patients were of serotypes G1-G4. The risk of severe diarrhea was particularly great in children who were not exclusively breast-fed in early infancy and who also lacked piped water in their homes (for children with both characteristics OR=6.8, 95% CI=3.6-12.8). The high prevalence of rotavirus and its association with severe diarrhea underscores the need for rotavirus vaccines. Interventions to educate mothers and improve access to safe water should augment the impact of rotavirus vaccines in preventing severe diarrhea.  (+info)

Malnutrition modifies pig small intestinal inflammatory responses to rotavirus. (7/1527)

Infectious diarrheal diseases and malnutrition are major causes of child morbidity and mortality. In this study, malnutrition was superimposed on rotavirus infection in neonatal piglets to simulate the combined intestinal stress of viral enteritis in malnourished infants. Two-day-old piglets were assigned to three treatment groups as follows: 1) noninfected, fully nourished; 2) infected, fully nourished; and 3) infected, malnourished. Intestinal indices of inflammation were monitored over the subsequent 2-wk period. Intestinal damage and diarrhea were observed within 2 d of rotavirus infection and began to subside in nourished piglets by d 9 but persisted through d 16 postinfection in malnourished piglets. Rotavirus upregulated small intestinal expression of major histocompatibility complex (MHC) class I and class II genes; malnutrition intensified MHC class I gene expression and suppressed MHC class II expression. Jejunal CD4(+) and CD8(+) T-lymphocyte numbers were elevated for infected, nourished piglets on d 2, 9 and 16 postinfection. Malnutrition did not significantly affect the local expansion of T cell subsets in response to rotavirus. Intestinal prostaglandin E2 (PGE2) concentrations were elevated early after rotavirus infection independent of nutritional state. By d 9, PGE2 concentrations returned to baseline in infected, nourished piglets but remained elevated in malnourished piglets, corresponding to diarrhea observations. Together, the results identify intestinal indices of inflammation that are modulated by malnutrition and prompt reconsideration of current models of rotavirus pathophysiology.  (+info)

Rotavirus vaccine for the prevention of rotavirus gastroenteritis among children. Recommendations of the Advisory Committee on Immunization Practices (ACIP). (8/1527)

These recommendations represent the first statement by the Advisory Committee on Immunization Practices (ACIP) on the use of an oral, live rotavirus vaccine licensed by the Food and Drug Administration on August 31, 1998, for use among infants. This report reviews the epidemiology of rotavirus, describes the licensed rotavirus vaccine, and makes recommendations regarding its use for the routine immunization of infants in the United States. These recommendations are based on estimates of the disease burden of rotavirus gastroenteritis among children in the United States and on the results of clinical trials of the vaccine. Rotavirus affects virtually all children during the first 5 years of life in both developed and developing countries, and rotavirus infection is the most common cause of severe gastroenteritis in the United States and worldwide. In the United States, rotavirus is a common cause of hospitalizations, emergency room visits, and outpatient clinic visits, and it is responsible for considerable health-care costs. Because of this large burden of disease, several rotavirus vaccines have been developed. One of these vaccines - an oral, live, tetravalent, rhesus-based rotavirus vaccine (RRV-TV) -- was found to be safe and efficacious in clinical trials among children in North America, South America, and Europe and on the basis of these studies is now licensed for use among infants in the United States. The vaccine is an oral, live preparation that should be administered to infants between the ages of 6 weeks and 1 year. The recommended schedule is a three-dose series, with doses to be administered at ages 2, 4, and 6 months. The first dose may be administered from the ages of 6 weeks to 6 months; subsequent doses should be administered with a minimum interval of 3 weeks between any two doses. The first dose should not be administered to children aged > or =7 months because of an increased rate of febrile reactions after the first dose among older infants. Second and third doses should be administered before the first birthday. Implementation of these recommendations in the United States should prevent most physician visits for rotavirus gastroenteritis and at least two-thirds of hospitalizations and deaths related to rotavirus.  (+info)