To have a better knowledge of the epidemiological and clinical aspects of rotavirus (RV) infection treated at out-patient clinics, we carried out a study in five centers (one hospital type I, and four out-patient clinics) of Miranda state, between february 2006 and january 2007. We evaluated 194 children <5 years old with acute diarrhea and analyzed the following characteristics: gender, age, socioeconomic condition, breastfeeding, nutritional status, clinical characteristics, rotavirus diagnosis and typing by Enzyme Linked immuno Sorbent Asssay (EISA) and G typing by RT-PCR, respectively. The population presented the following characteristics: 53% males; mean age, 17.
View Article and Find Full Text PDFBackground: Peak incidence of rotavirus gastroenteritis is seen in infants between 6 and 24 months of age. We therefore aimed to assess the 2-year efficacy and safety of an oral live attenuated human rotavirus vaccine for prevention of severe gastroenteritis in infants.
Methods: 15 183 healthy infants aged 6-13 weeks from ten Latin American countries randomly assigned in a 1 to 1 ratio to receive two oral doses of RIX4414 or placebo at about 2 and 4 months of age in a double-blind, placebo-controlled phase III study were followed up until about 2 years of age.
The feces of 397 patients with acute diarrheal disease (ADD) and of other 121 patients without diarrea (control group) were studied in the state of Mérida, Venezuela, from June 1993 to December 1994. The genus Aeromonas was identified in patients with ADD in 11.83% and in 5.
View Article and Find Full Text PDFUnlabelled: The effect of nutritional status on protective efficacy of a live attenuated human rotavirus vaccine (RIX4414) was studied. Vaccine protection was evaluated through a secondary analysis of data from an efficacy study conducted in Brazil, Mexico, and Venezuela. Vaccine efficacy against rotavirus gastroenteritis (RVGE) was similar in well-nourished and malnourished infants: 74.
View Article and Find Full Text PDFBackground: Hospital-based studies to determine the etiology of deaths from diarrhea are scarce. In this study, we specifically analyzed deaths due to rotavirus to assess the rotavirus impact on diarrhea mortality.
Methods: To determine the rotavirus proportion contributing to mortality due to diarrhea, we analyzed data obtained from a hospital-based mortality surveillance, conducted over 7 years, in the Ciudad Hospitalaria Dr.
Rev Panam Salud Publica
October 2006
Objective: To assess the cost of medical care for rotavirus gastroenteritis and the cost-effectiveness of the antiretroviral vaccine in Venezuelan children under five.
Methods: We used an economic model that comprises epidemiologic information, vaccine efficacy, and the cost of medical care in connection with rotavirus gastroenteritis, viewed from a social perspective. In order to determine the effectiveness of the vaccine, we estimated the number of hospitalized cases, of medical visits, and of deaths averted after vaccination.
Background: The safety and efficacy of an attenuated G1P[8] human rotavirus (HRV) vaccine were tested in a randomized, double-blind, phase 3 trial.
Methods: We studied 63,225 healthy infants from 11 Latin American countries and Finland who received two oral doses of either the HRV vaccine (31,673 infants) or placebo (31,552 infants) at approximately two months and four months of age. Severe gastroenteritis episodes were identified by active surveillance.
The immune response elicited by the rotavirus nonstructural protein NSP4 and its potential role in protection against rotavirus disease are not well understood. We investigated the serological response to NSP4 and its correlation with disease protection in sera from 110 children suffering acute diarrhea, associated or not with rotavirus, and from 26 children who were recipients of the rhesus rotavirus tetravalent (RRV-TV) vaccine. We used, as antigens in an enzyme-linked immunosorbent assay (ELISA), affinity-purified recombinant NSP4 (residues 85 to 175) from strains SA11, Wa, and RRV (genotypes A, B, and C, respectively) fused to glutathione S-transferase.
View Article and Find Full Text PDFBackground: A live attenuated monovalent rotavirus vaccine RIX4414 was developed with a human strain of G1P1A P[8] specificity to reduce the rotavirus burden in children.
Methods: A double blind, randomized, placebo-controlled study evaluated the efficacy, immunogenicity, safety and reactogenicity of 2 oral doses of RIX4414 (10(4.7), 10(5.
An oral, human-derived monovalent (G1P1A) rotavirus vaccine, strain RIX4414, has been developed by GlaxoSmithKline, Rixensart, Belgium. The safety, immunogenicity and efficacy of this vaccine were evaluated in a randomized, double-blind, placebo-controlled, phase IIb trial conducted in Brazil, Mexico and Venezuela. Healthy infants were given two doses of vaccine (104.
View Article and Find Full Text PDFThe need for safe and effective vaccines to reduce morbidity and mortality caused by rotavirus gastroenteritis in children is well-known. A live attenuated monovalent rotavirus vaccine (Rotarix) containing human rotavirus strain RIX4414 of G1P1A P[8] specificity is being developed to meet the global need. An overview of RIX4414 trials in developed and developing settings is presented for 3 selected trials conducted in Finland (pilot study), Latin America (Brazil, Mexico and Venezuela) and Singapore involving 5024 infants.
View Article and Find Full Text PDFUsing an intracellular cytokine assay, we recently showed that the frequencies of rotavirus (RV)-specific CD4(+) and CD8(+) T cells secreting INFgamma, circulating in RV infected and healthy adults, are very low compared to the frequencies of circulating cytomegalovirus (CMV) reactive T cells in comparable individuals. In children with acute RV infection, these T cells were barely or not detectable. In the present study, an ELISPOT assay enabled detection of circulating RV-specific INFgamma-secreting cells in children with RV diarrhea but not in children with non-RV diarrhea without evidence of a previous RV infection.
View Article and Find Full Text PDFBackground: The first licensed rotavirus vaccine was withdrawn from use in the United States because of a low risk of intussusception. Consequently tests of new rotavirus vaccines will require some baseline knowledge of the rates and treatment of intussusception in countries where these vaccines will be tested. Therefore the objective of this study was to assess hospitalization rates and describe the epidemiologic and clinical characteristics of intussusception in Carabobo, Venezuela.
View Article and Find Full Text PDFDuring a phase 3 clinical trial of rhesus monkey rotavirus-based quadrivalent vaccine in Venezuela, 2207 infants received 3 oral doses of vaccine (4 x 105 plaque-forming units/dose) or placebo at ages approximately 2, 3, and 4 months; 219 (14%) of 1537 stools obtained during 1550 diarrheal episodes in postvaccination surveillance were rotavirus-positive by enzyme-linked immunosorbent assay. With the use of various VP7 and VP4 primers for genotyping purposes, 213 of 219 rotavirus-positive stools were analyzed by reverse-transcription polymerase chain reaction. Twenty-nine (14%) of 213 rotavirus-positive stools contained at least 2 distinct rotavirus strains: a low-titered vaccine strain(s) and a second strain that, when possible, was studied further and found to be a wild-type rotavirus strain.
View Article and Find Full Text PDFBackground: Knowledge of the impact of rotavirus-associated disease on the health care systems of South America can aid in defining strategies for diagnosis, management and prevention. Up to date information on the impact of rotavirus disease in South America is scarce.
Aim: To determine prospectively the impact of rotavirus disease as a cause of medical visits and hospitalizations at three large sentinel pediatric hospitals in Argentina, Chile and Venezuela.
This report describes the results of additional analyses of the trial carried out with the rhesus rotavirus-based quadrivalent vaccine in Venezuela. In the present study, we re-examined the data from this previous rotavirus vaccine trial to assess the statistical interaction between vaccine efficacy and (i) the duration of efficacy into the second year of life, (ii) socioeconomic conditions, and (iii) rotavirus seasonality. We found that among Venezuelan children, the rotavirus vaccine confers protection against severe diarrhea during the first 2 years of life independently of socioeconomic conditions and seasonality.
View Article and Find Full Text PDF464 stool specimens from children under 5 with acute diarrheal disease and other 149 specimens from the control group were studied from July, 1993, to May, 1995. The specimens were collected at the Pediatric Emergency Department of the Autonomous Institute of the Teaching Hospital of Los Andes, Mérida, Venezuela. The presence of the internationally recommended bacterial, parasitary and viral agents was investigated.
View Article and Find Full Text PDFThe epidemiological features of rotavirus infection may be quite relevant for evaluation of the performance of a rotavirus vaccine in different settings, as well as for monitoring its impact during vaccination under routine conditions. This article describes some important issues regarding rotavirus epidemiology in Venezuela, where major field trials of rotavirus vaccine have been carried out. Rotaviruses was significantly more frequently observed in inpatient (43%) than in outpatient (21%) consultations for diarrhea in infants and young children.
View Article and Find Full Text PDFRev Panam Salud Publica
September 1999
In four cities of Venezuela a study was carried out to evaluate the epidemiological, clinical, and etiological characteristics of acute diarrhea in children under 5 years of age. The study was done between June 1993 and May 1995 and involved children who were seen in a hospital, 2,552 with diarrhea and 793 controls. The Fisher exact test was used for the statistical analysis of the results.
View Article and Find Full Text PDFThe presence of antibodies against Norwalk virus (NV) was studied in sera from different Venezuelan populations, using an enzyme immuno-assay (EIA) based on recombinant NV protein. Antibodies to NV were found in 47%-53% of urban subjects from Caracas, 83% of rural subjects from the west of the country, and 73%-93% of Amerindian subjects. The prevalences found in the rural and Amerindian groups were significantly higher than that in the urban group.
View Article and Find Full Text PDFBackground: Rotaviruses are the principal known etiologic agents of severe diarrhea among infants and young children worldwide. Although a rhesus rotavirus-based quadrivalent vaccine is highly effective in preventing severe diarrhea in developed countries, in developing countries its efficacy has been less impressive. We thus conducted a catchment study in Venezuela to assess the efficacy of the vaccine against dehydrating diarrhea.
View Article and Find Full Text PDFTo evaluate the epidemiological significance of HEp-2 cell-adherent Escherichia coli isolates in diarrheal disease, we performed a study with 513 Venezuelan infants with diarrhea and 241 age-matched controls to determine the prevalence of enteropathogenic E. coli (enteroadherent E. coli, enterotoxigenic E.
View Article and Find Full Text PDFThe most extensively explored strategy for rotavirus vaccination has been the Jennerian approach, which uses an antigenically related rotavirus strain from an animal host as the immunogen to induce protection against the 4 epidemiologically important group A rotavirus VP7 serotypes. Because this approach has shown limited efficacy, a modified Jennerian approach was developed with the goal of achieving broader antigenic coverage. Four VP7 serotypes were incorporated into a quadrivalent vaccine comprised of three rhesus-human rotavirus reassortants, each with 10 rhesus rotavirus genes and 1 human rotavirus gene that encodes VP7 serotype 1, 2, or 4 specificity; the rhesus rotavirus itself provides coverage for VP7 serotype 3.
View Article and Find Full Text PDFInformation concerning the disease burden of rotavirus, particularly in developing countries, has important implications for the use and for monitoring the impact of rotavirus vaccines. Although rotavirus has been recognized as the most frequent cause of hospitalization in the world, national estimates and specific information about the incidence of hospitalization for rotavirus gastroenteritis are very limited. Consequently, estimates of the incidence of hospitalization among children during the first 2 years of life in Venezuela were determined by extrapolation of data from a community-based study carried out in Caracas.
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