Detection of rotavirus types G8 and G10 among Brazilian children with diarrhea

Characterization of 49 rotavirus-positive stool specimens from children with diarrhea in the state of Rio de Janeiro, Brazil, in 1996 and 1997 revealed a great diversity of rotavirus G types. Conventional types G1 and G3 accounted for 27 and 12% of the infections, respectively, whereas 60% of the infections were caused by unconventional types G5 (25%), G10 (16%), and G8 (4%) and mixed G types (16%).     

Serotyping of group A rotaviruses in Egyptian neonates and infants less than 1 year old with acute diarrhea

Group A human rotavirus G serotypes were detected in stool specimens from neonates and infants with and without acute diarrhea in Cairo by using monoclonal antibodies in an enzyme-linked immunosorbent assay. Serotypes G1 and G4 predominated in all age groups. Mixed (G1 plus G4) and nontypeable specimens represented 16.1 and 38.7% of the total number serotyped, respectively.     

Immune response to three doses of quadrivalent rotavirus vaccine: 1-year follow-up

Twenty-eight children who received three doses of the quadrivalent rotavirus vaccine with 4 x 10(5) plaque-forming units (p.f.u.) were followed during a year after vaccination. Serum samples were obtained and evaluated for rotavirus IgA and neutralizing antibodies against vaccine and human rotavirus strains. At the end of the study, up to 61% of the children showed an increase in circulating IgA antibody levels. Nearly all of the vaccinated children increased their neutralizing antibody titres against the vaccine strains, and 25-54% against human rotavirus serotypes. After comparing the vaccinees with a population of children naturally infected with serotype G1 in the same study area, we conclude that three doses of 4 x 10(5) p.f.u. of the quadrivalent vaccine should prepare the child against future severe rotavirus diarrhea.     

Vaccination against rabies: construction and characterization of SAG2, a double avirulent derivative of SADBern

Both the G (VP7) and P (VP4) serotypes of human rotaviruses collected over a 10-year period from Japanese children with diarrhea were determined by recently-developed polymerase chain reaction-based typing assays. The combination of G1 and P8 was found in 65.2% and the combination of G2 and P4 was found in 15.2%. For the rest of the specimens, only a few other combinations occurred and their relative frequencies were less than 10%. The viruses carrying P9 were always associated with G3 as is the prototype strain AU-1.     

Epidemiology of symptomatic human rotaviruses in Bangalore and Mysore, India, from 1988 to 1994 as determined by electropherotype, subgroup and serotype analysis

Epidemiology of symptomatic rotaviruses from Bangalore and Mysore in Southern India was investigated. While serotype G3 predominated throughout the 7-year study period from 1988 to 1994 in Bangalore, serotype G1 was more predominant than serotype G3 in Mysore during 1993 and 1994. Serotype G2 strains were either not detected or infrequently observed in both the cities. However, several strains with subgroup I and 'short' RNA pattern that exhibited high reactivity with typing MAbs specific for serotype 2 as well as other serotypes were detected throughout the period. Among the nonserotypeable strains from both cities, several exhibited dual subgroup (SGI + II) or subgroup I specificity and 'long' RNA pattern indicating their probable animal origin. Notably, a gradual, yet highly significant reduction in rotavirus gastroenteritis, from 45.3% in 1988 to 1.8% during 1994, was observed in Bangalore in stark contrast to the consistently high (about 34%) incidence of asymptomatic infections among neonates by I321-like G10P11 type strains during the same period. Moreover, I321-like asymptomatic strains were not detected in children with diarrhea.     

Managing pain after coronary artery bypass surgery

From June 1992 to May 1993, rotaviruses were detected by an immunoenzymatic assay in 159 (49.5%) of 321 children admitted to the hospital with acute diarrhea. Of the 159 cases ELISA positive, 80 samples were chosen at random to investigate subgroups and serotypes of group A human rotavirus. By the ELISA test 9 (11.3%) of the strains were subgroup I, 46 (57.5%) were subgroup II, and 25 (31.3%) could not be grouped. The serotype G1 was identified in 52 cases (65%), G2 in 11 cases (13.8%), G3 in 1 case (1.2%), and 7 cases (8.8%) showed more than one serotype. By electrophoretic analysis of viral RNA, 137 (42.7%) of the samples exhibited an RNA pattern. The long pattern (59.1%) prevailed over the short pattern (35.8%), and by coelectrophoresis 8 different electropherotypes were found throughout the period of study. These results illustrate the great variety of rotavirus strains in this region of the country.     

Homotypic and heterotypic serum neutralizing antibody response to rotavirus proteins following natural primary infection and reinfection in children

Worldwide trials of rotavirus vaccines are currently in progress, but the basis of cross-reactive immunity between rotavirus serotypes is yet to be elucidated. The involvement of the outer capsid proteins, VP7 and VP4, in the production of cross-reactive neutralizing antibody (N-Ab) is unclear, and may be important for the success of animal rotavirus-based candidate vaccines that lack a VP4 of human rotavirus origin. In this study, VP7- and VP4-specific N-Ab was assayed in sera from children experiencing primary (27 children) and/or secondary (14 children) rotavirus infections using human-animal reassortant strains. These reassortants contained genes encoding the major G- and P-types found in human infection, including G1, 2, 3, and 4; or P1A[8], 1B[4], and 2[6]. After primary infection, the N-Ab response to VP7 was generally serotype-specific, whereas the response to VP4 was heterotypic. After reinfection (with the same or different serotypes) there was a significant increase (P=0.0313) in the number of VP7 serotypes seroconverted against with no broadening of cross-reactivity to VP4. Increases in homotypic N-Ab titer, following both primary and secondary infection, were greater against VP7 than VP4, with the seroconversion against VP7 being significantly greater upon reinfection than following primary infection (P=0.0280). In summary, heterotypic N-Ab produced following primary infection appears to be primarily against VP4. However, upon reinfection, VP7 becomes increasingly immunodominant both in terms of cross-reactive N-Ab production and increases in N-Ab titer.     

Laparoscopic resection of a benign true cyst of the spleen with the harmonic scalpel producing high levels of CA 19-9 and carcinoembryonic antigen

BACKGROUND: Oral ingestion of immunoglobulins in humans has been shown to be effective as prophylaxis against enteric infections. However, its therapeutic effect in children with infectious diarrhea has hitherto not been proven. We treated children with rotavirus diarrhea with immunoglobulins extracted from immunized bovine colostrum (IIBC) containing high titers of antibodies against four rotavirus serotypes. METHODS: In this double blind placebo-controlled trial, 80 children with rotavirus diarrhea were randomly assigned to receive orally either 10 g of IIBC (containing 3.6 g of antirotavirus antibodies) daily for 4 days or the same amount of a placebo preparation. The daily stool output (grams/kg/day), intake of oral rehydration solution (ml/kg/day), stool frequency (number of stools/day) and presence of rotavirus in stool were monitored for the 4 days during treatment. RESULTS: Children who received IIBC had significantly less daily and total stool output and stool frequency and required a smaller amount of oral rehydration solution than did children who received placebo (P < 0.05). Clearance of rotavirus from the stool was also earlier in the IIBC group compared with the placebo group (mean day, 1.5 vs. 2.9, P < 0.001). No adverse reactions from the colostrum treatment were observed. CONCLUSIONS: Treatment with antirotavirus immunoglobulin of bovine colostral origin is effective in the management of children with acute rotavirus diarrhea.     

Comparative evaluation of reactogenicity and immunogenicity of two dosages of oral tetravalent rhesus rotavirus vaccine. US Rhesus Rotavirus Vaccine Study Group

OBJECTIVE: To compare the safety and immunogenicity of two dosages of tetravalent rhesus rotavirus vaccine (RRV-TV) and the effect of age at dosing. METHODS: A total of 195 infants were stratified by age into 2 groups, 6 to 12 weeks and 16 to 24 weeks, and randomly assigned to receive a single dose of placebo or RRV-TV containing either 4 x 10(5) or 4 x 10(6) plaque-forming units (pfu). Symptoms were recorded for 5 days after vaccination. Anti-rotavirus IgA and neutralizing antibody to human rotavirus serotypes G1 to G4 and RRV were measured in serum obtained pre- and postvaccination. RESULTS: Rates of fever > 38 degrees C (9%), diarrhea (6%) and vomiting (8%) were similar in all groups. IgA (69% vs. 49%, P = 0.02) and RRV (85% vs. 66%, P = 0.004) seroconversion rates were significantly higher in the 4 x 10(6) pfu vaccine group as were antibody titers to RRV (440.2 vs. 263.7, P = 0.04). Older infants demonstrated significantly higher seroconversion rates and antibody titers for IgA (71% vs. 52%, P = 0.03; and 110.6 vs. 54.8, P = 0.004) and RRV (92% vs. 66%, P = 0.05 and 498.3 vs. 205.6, P = 0.01) at either dose level than did the younger infants. There were no significant differences in seroconversion rates or antibody titers to human rotavirus types G1 to G4 between the two vaccination groups. CONCLUSIONS: RRV-TV at a dose of 4 x 10(6) pfu can be safely administered to infants 6 to 24 weeks of age. A single dose of 4 x 10(6) pfu of RRV-TV was significantly more immunogenic than a single dose of 4 x 10(5) pfu but did not improve responses to the human serotypes. Older vaccine recipients demonstrated significantly higher IgA and neutralizing antibody seroconversion rates and antibody titers than younger infants independent of dosage.     

Antibody response to outer membrane protein of nontypeable Haemophilus influenzae in otitis-prone children

One of the major outer membrane proteins of nontypeable Haemophilus influenzae, P6, is highly conserved among strains, serves as a target for bactericidal antibody, and has been proposed as a possible vaccine candidate. The serum antibody response to P6 was studied in otitis-prone and normal children by an enzyme-linked immunosorbent assay. Of 20 otitis-prone children, 12 (60%) had a serum IgG antibody response to P6 after otitis media; however, the mean acute antibody level for the group, 4.6 micrograms/ml, was not significantly different from the convalescent level, 5.4 micrograms/ml. Anti-P6 antibody levels were also measured longitudinally for 10 to 25 months in 30 otitis-prone and 13 healthy children. Antibody levels increased sevenfold in the normal group compared with less than three-fold for the otitis-prone group and were significantly higher in the normal children after the age of 18 months (p < 0.05). Finally, otitis-prone children who had two or more episodes of otitis media with nontypeable H. influenzae did not have an anamnestic antibody response to P6. The failure to recognize P6 as a specific immunogen may account for recurrent infections. Moreover, the data suggest that otitis-prone children may not respond adequately to a vaccine containing P6.     

Antigenic and genomic diversity of human rotavirus VP4 in two consecutive epidemic seasons in Mexico

In the present investigation we characterized the antigenic diversity of the VP4 and VP7 proteins in 309 and 261 human rotavirus strains isolated during two consecutive epidemic seasons, respectively, in three different regions of Mexico. G3 was found to be the prevalent VP7 serotype during the first year, being superseded by serotype G1 strains during the second season. To antigenically characterize the VP4 protein of the strains isolated, we used five neutralizing monoclonal antibodies (MAbs) which showed specificity for VP4 serotypes P1A, P1B, and P2 in earlier studies. Eight different patterns of reactivity with these MAbs were found, and the prevalence of three of these patterns varied from one season to the next. The P genotype of a subset of 52 samples was determined by PCR. Among the strains characterized as genotype P[4] and P[8] there were three and five different VP4 MAb reactivity patterns, respectively, indicating that the diversity of neutralization epitopes in VP4 is greater than that previously appreciated by the genomic typing methods.     

Rotavirus

Rotavirus, the most common diarrheal pathogen in children worldwide, causes approximately one third of diarrhea-associated hospitalizations and 800,000 deaths per year. Because natural infection reduces the incidence and severity of subsequent episodes, rotavirus diarrhea might be controlled through vaccination. Serotypespecific immunity may play a role in protection from disease. Tetravalent rhesus-human reassortant rotavirus vaccine (RRV-TV) (which contains a rhesus rotavirus with serotype G3 specificity and reassortant rhesus-human rotaviruses with G1, G2, and G4 specificity) provides coverage against the four common serotypes of human rotavirus. In clinical trials in industrialized countries, RRV-TV conferred 49% to 68% protection against any rotavirus diarrhea and 61% to 100% protection against severe disease. This vaccine was licensed by the U.S. Food and Drug Administration on August 31, 1998, and should be cost-effective in reducing diarrheal diseases in industrialized countries. The vaccine's efficacy and cost-effectiveness in developing countries should be evaluated.     

Characterization of field strains of group A bovine rotaviruses by using polymerase chain reaction-generated G and P type-specific cDNA probes

Dot and Northern blot hybridization assays were used to analyze field strains of group A bovine rotaviruses (BRVs) by using nucleic acid probes representing P and G type specificities. The probes were prepared by polymerase chain reaction amplification of hyperdivergent regions of the cloned VP4 (nucleotides 211 to 686) and VP7 (nucleotides 51 to 392) genes from four serotypically distinct (in P or G types) strains of rotaviruses: NCDV (G6, P1), IND (G6, P5), 69M (G8, P10), and Cr (G10, P11). The P and G type cDNA probes were radiolabeled with [32P]dCTP and hybridized with RNA extracted from reference cell culture-passaged rotavirus strains or the field samples. The field samples were obtained from young diarrheic calves from Ohio, Nebraska, Washington State, and Canada. The cDNA probes were specific for their respective G or P types on the basis of analysis of known P and G type reference strains. The G typing analysis of 102 field samples revealed that 36.3% (37 of 102) were G6, 2.9% (3 of 102) were G8, 12.7% (13 of 102) were G10, and 23.5% (24 of 102) were untypeable. The P typing results for 93 samples indicated that 2.2% (2 of 93) were P1 (NCDV-like), 20.4% (19 of 93) were P5 (UK-like), 9.3% (10 of 93) were P11 (B223-like), and 40.8% (38 of 93) were untypeable. This is the first report of the identification among BRV strains in North America of a G type other than G6 or G10. Our report further confirms that G6, P5 rotaviruses are predominant among the BRV field strains that we examined, and the P types of these strains differ from that of the BRV vaccine strain used in the United States (G6, P1). The large number of untypeable G (23.5%) and P (40.8%) types suggests that other or new P and G types exist among BRV field strains.     

Monitoring of rotavirus infection in a paediatric hospital by RNA electrophoresis

During the spring of 1987 and the autumn of 1988, stool specimens were collected from infants and young children in the paediatric unit at H. F. Verwoerd Hospital, Pretoria, and examined for the presence of rotaviruses to assess the potential for hospital-acquired infection in the paediatric wards. Stool samples were also collected from children admitted to the hospital for causes unrelated to gastro-enteritis to investigate the possible asymptomatic carriage of rotavirus in this population. Hospital-acquired rotavirus infection was determined in only 9% of cases. Very little asymptomatic carriage of the virus was identified. Electrophoretic analysis of the rotavirus strains showed that the majority of the infections (20 of 42) were associated with a particular strain with a long RNA profile, while 7 minor strains co-circulated (5 with a long electrophoretype and 2 with a short one). An apparent small outbreak of nosocomial infection with a single strain was observed to occur in one of the paediatric wards during the spring and early summer.     

Heterotypic protection following oral immunization with live heterologous rotaviruses in a mouse model

A Jennerian approach using live animal viruses to immunize humans is the current lead strategy for developing rotavirus vaccines. This strategy has been modified by incorporating human rotavirus VP7 genes into vaccine strains to induce serotype-specific neutralizing antibodies to human strains. However, the role of homotypic versus heterotypic immunity in protection is unclear. To investigate the importance of serotype-specific immunity in a mouse model, mice were immunized with rhesus rotavirus (RRV: G3, P5[3]), RRV-based modified Jennerian vaccine strains DxRRV (G1, P5[3]), DS1xRRV (G2, P5[3]), or ST3xRRV (G4, P5[3]), or bovine rotavirus NCDV (G6, P6[1]) and challenged with murine rotavirus ECw (G3, P[16]). Mice immunized with modified Jennerian vaccines exhibited complete to near-complete protection from challenge. NCDV-immunized mice also showed partial protection. The protection was correlated with fecal IgA levels to VP6, not serum IgG responses. Modified Jennerian vaccines induce both heterotypic and homotypic immunity in mice.     

Genetic and antigenic analysis of human rotavirus prevalent in Al-Taif, Saudi Arabia

The subgroup, serotype and electropherotype diversity of human rotavirus strains was investigated in Al-Taif, Saudi Arabia. Out of 349 faecal samples collected from diarrhoeic children, 150 (43 percent) tested rotavirus positive by a group-A specific enzyme-linked immunosorbent assay (ELISA). The majority (87 percent) of the infected children were below 2 years of age. Subgrouping and serotyping of rotaviruses with specific monoclonal antibodies showed that of the 150 rotavirus positive specimens, 17 percent belonged to subgroup I, 59 per cent belonged to subgroup II, and 24 percent were neither subgroup I nor subgroup II. The specimens were typed, as serotype 1 (43 percent), serotype 2 (5 percent), serotype 3 (11 percent), serotype 4 (10 percent) or mixed serotypes (3 percent). The remaining 41 (27 percent) specimens were untypeable. None of the serotypes showed association with a particular age group. An electrophoretic analysis of viral RNA revealed 11 distinct patterns (six long and five short). The majority, 78 percent were long patterns and 22 percent were short patterns. Analysis of the specimens for which subgroups, serotypes and electropherotypes were available indicated that a given RNA pattern does not correspond to a particular subgroup or serotype.     

Survey on the distribution of the gene 4 alleles of human rotaviruses by polymerase chain reaction

The presence of six gene 4 alleles (or VP4 genotypes) in human rotaviruses has been recognized. Using 16 representative cultivable human rotavirus strains, we confirmed the specificity of VP4 genotyping by polymerase chain reaction (PCR) using the nested oligonucleotides specific to each of the four representative gene 4 alleles. Using the PCR, we surveyed the gene 4 alleles of 199 human rotaviruses in stools collected in Japan and Thailand. Strains with the gene 4 allele, corresponding to P1A serotype, were shown to be the most prevalent, but two strains with P2 gene 4 allele and one strain with P3 gene 4 allele were detected in Thailand and in Japan, respectively.