RESUMO
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 (104.7, 105.2 or 105.8 ffu) or placebo at age 2 and 4 months, with routine DTPw-HBV and Hib vaccines. OPV was given separately, at least 2 weeks before or after administration of the study vaccine. A total of 2155 infants were enrolled, of whom 1618 received one of the three vaccine viral concentrations and 537 were given placebo. Analysis of efficacy included diarrheal episodes occurring from 2 weeks after second dose until one year of age. Efficacy rates against any rotavirus gastroenteritis, severe rotavirus gastroenteritis and hospitalizations for rotavirus disease were as high as 70% (46-84%; 95%CI), 86% (63-96%; 95%CI), and 93% (54-100%; 95%CI), respectively. For non-G1 (mainly G9) serotypes, RIX4414 vaccine conferred protection as high as 83% (40-97%; 95%CI) against severe gastroenteritis. A decrease was noted in the incidence of severe rotavirus-related gastroenteritis after first dose. It is demonstrated that two doses of RIX4414 are highly efficacious against severe rotavirus gastroenteritis and hospitalization, including disease caused by non-G1 strains, namely G9 serotypes.
Assuntos
Gastroenterite/prevenção & controle , Infecções por Rotavirus/prevenção & controle , Vacinas contra Rotavirus , Vacinas Atenuadas , Administração Oral , Brasil , Método Duplo-Cego , Gastroenterite/epidemiologia , Hospitalização/estatística & dados numéricos , Humanos , Incidência , Lactente , México , Infecções por Rotavirus/epidemiologia , Vacinas contra Rotavirus/administração & dosagem , Vacinas contra Rotavirus/efeitos adversos , Vacinas contra Rotavirus/imunologia , Vacinas Atenuadas/administração & dosagem , Vacinas Atenuadas/efeitos adversos , Vacinas Atenuadas/imunologia , VenezuelaRESUMO
Las campilobacterias termotolerantes son causa frecuente de enfermedad diarreica aguda en niños en todo el mundo. En el presente estudio se evaluaron dos de los factores de virulencia de importancia en enteropatógenos: la capacidad de adherencia e invasión en células HEp-2 de diferentes especies de campylobacter (C.jejuni subsp. jejuni, C coli y C. lari), aisladas como único enteropatógeno de niños menores de 5 años con diarrea inflamatoria y secretora; además, se incluyeron aislados de niños asintomáticos. Los resultados no revelaron diferencia estadísticamente significativa en la adherencia e invasión de los aislados de ambos grupos de niños (diarrea y asintomáticos), ni entre los asilados de diarrea inflamatoria y secretora. La variación en las manifestaciones clínicas en estos pacientes y la presencia de portadores asintomáticos podría atribuirse a diferencias en el huésped, es decir, participación activa de la respuesta inmune, o al tipo de cepa involucrada, ya que se han descrito otros factores de virulencia en estos microorganismos
Assuntos
Humanos , Masculino , Pré-Escolar , Feminino , Aderência Bacteriana , Campylobacter , Campylobacter coli , Campylobacter jejuni , Diarreia Infantil , Parasitologia , Virulência , MicrobiologiaRESUMO
BACKGROUND: 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. METHODS: A 2-year prospective surveillance for rotavirus-associated medical visits and hospitalizations was conducted during 1997 through 1998 at three large sentinel public hospitals, one each in Argentina, Chile and Venezuela. A common surveillance protocol was implemented at the three sites, and a representative number of nonbloody diarrhea stool samples from children <36 months of age were tested for rotavirus by enzyme-linked immunosorbent assay. RESULTS: For our target age group, acute diarrhea-associated medical visits/hospitalizations represented 41%/2%, 5%/6% and 9%/13% of all medical visits/all hospitalizations at the Argentinean, Chilean and Venezuelan sites, respectively (P < 0.001 for difference among the three sites). Rotavirus detection rates among a total of 5,801/1,256 medical visit/hospitalization diarrhea stool samples tested were 39%/71% in Argentina, 34%/47% in Chile and 29%/38% in Venezuela (P < 0.01 by chi square for difference among the three sites). Rotavirus was associated with a mean of 1.5, 1.8 and 3% of total medical visits and 1.6, 2.8 and 5% of hospitalizations among children <36 months of age at the Argentinean, Chilean and Venezuelan sites, respectively. Seasonality was evident for medical visits at all three sites (although less striking in Chile) with peak activity occurring between November and May. Rotavirus-associated hospitalizations had a marked peak in Venezuela, represented largely by short stays, but not in Argentina and Chile. CONCLUSIONS: Rotavirus was a significant cause of medical visits at all three sentinel sites. Rotavirus caused less hospitalizations than previously reported in Argentina and Chile. On the basis of our findings we estimate that approximately 106,000/ 21,000, 48,000/8,000 and 98,000/31,000 rotavirus-associated medical visits/hospitalizations occur yearly in Argentina, Chile and Venezuela, respectively.
Assuntos
Hospitalização/estatística & dados numéricos , Visita a Consultório Médico/estatística & dados numéricos , Infecções por Rotavirus/epidemiologia , Argentina/epidemiologia , Pré-Escolar , Chile/epidemiologia , Diarreia/virologia , Ensaio de Imunoadsorção Enzimática , Feminino , Hospitais Pediátricos/estatística & dados numéricos , Humanos , Lactente , Recém-Nascido , Masculino , Estudos Prospectivos , Rotavirus/isolamento & purificação , Infecções por Rotavirus/diagnóstico , Infecções por Rotavirus/economia , Vigilância de Evento Sentinela , Venezuela/epidemiologiaRESUMO
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.
Assuntos
Infecções por Rotavirus/epidemiologia , Infecções por Rotavirus/prevenção & controle , Rotavirus/imunologia , Vacinas Virais/farmacologia , Fatores Etários , Animais , Diarreia/epidemiologia , Diarreia/prevenção & controle , Método Duplo-Cego , Feminino , Humanos , Lactente , Macaca mulatta , Masculino , Estações do Ano , Fatores Socioeconômicos , Venezuela/epidemiologiaRESUMO
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. Rotaviruses were the most important agents, both in terms of their frequency (30%) and their association with dehydration (58%). Following in importance were Campylobacter spp. (13%) and Escherichia coli classical O serogroups (9%), but their association with diarrhea was only statistically significant among children less than 3 months old, a fact that is particularly important from the standpoint of treatment. The importance of age was confirmed as a determining factor in the prevalence and severity of diarrhea.
Assuntos
Diarreia/epidemiologia , Doença Aguda , Demografia , Humanos , Fatores Socioeconômicos , Venezuela/epidemiologiaRESUMO
The 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. There was a high prevalence of rotavirus illness, regardless of socioeconomic conditions, but the risk of dehydration was greater among the lower socioeconomic groups. Rotavirus disease occurs year-round, with a slight seasonal pattern. Eighty-five percent of rotavirus-positive diarrheal episodes, as well as 86% of cases of dehydration due to rotavirus, occurred during the first year of life. However, rotavirus illnesses occur less commonly during the first months of life (0-2 months), which may be a result of protection by transplacental antibodies. The pattern of acquisition of rotavirus antibody was consistent with this age distribution of disease and with optimal age for vaccination. Thus, regional epidemiological characteristics of rotavirus infection may affect optimal performance of rotavirus vaccine.
Assuntos
Diarreia Infantil/epidemiologia , Infecções por Rotavirus/epidemiologia , Distribuição por Idade , Pré-Escolar , Diarreia Infantil/induzido quimicamente , Fezes/virologia , Humanos , Programas de Imunização , Lactente , Recém-Nascido , Rotavirus/classificação , Rotavirus/isolamento & purificação , Infecções por Rotavirus/imunologia , Estações do Ano , Sorotipagem , Distribuição por Sexo , Classe Social , Venezuela/epidemiologiaRESUMO
464 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, MÚrida, Venezuela. The presence of the internationally recommended bacterial, parasitary and viral agents was investigated. The commonest bacteria isolated as unique pathogens were: Shigella (42.85), Shigella sonnei, the most found, (66.67), and the thermotolerant Campylobacter, Aeromonas sp. and enteropathogenous Escherichia coli, with 15; 15 and 13.5, respectively. 6.5 of parasites and 24.12 of Rotavirus were also found. It was concluded that in the period of time under study the infectious and mainly, the bacterial origin is an important cause of acute diarrheal disease in Mérida.
Assuntos
Humanos , Masculino , Feminino , Lactente , Pré-Escolar , Diarreia , Fezes , Doença Aguda , VenezuelaRESUMO
464 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. The commonest bacteria isolated as unique pathogens were: Shigella (42.85%), Shigella sonnei, the most found, (66.67%), and the thermotolerant Campylobacter, Aeromonas sp. and enteropathogenous Escherichia coli, with 15; 15 and 13.5%, respectively. 6.5% of parasites and 24.12% of Rotavirus were also found. It was concluded that in the period of time under study the infectious and mainly, the bacterial origin is an important cause of acute diarrheal disease in Mérida.
Assuntos
Diarreia/microbiologia , Fezes/microbiologia , Doença Aguda , Pré-Escolar , Feminino , Humanos , Lactente , Masculino , VenezuelaRESUMO
The 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. Although about 50% of the children studied were seropositive for NV by the age of 5 years, only four (0.4%) of 1120 faecal samples from children with diarrhoea which were tested for the presence of NV antigen by sandwich EIA were found positive. An increase of at least 4-fold in the titre of anti-NV IgA was found in three (5%) of 61 pairs of sera taken during and 1 month after an acute episode of diarrhoea not due to rotavirus. NV was therefore not a predominant aetiological cause of gastro-enteritis in young children in Venezuela between 1993 and 1995, although it can be the cause of diarrhoea in infants.
Assuntos
Infecções por Caliciviridae/epidemiologia , Gastroenterite/virologia , Vírus Norwalk/imunologia , Adolescente , Adulto , Anticorpos Antivirais/análise , Criança , Pré-Escolar , Fezes/virologia , Feminino , Humanos , Técnicas Imunoenzimáticas , Indígenas Sul-Americanos , Lactente , Recém-Nascido , Masculino , Pessoa de Meia-Idade , Vírus Norwalk/isolamento & purificação , Gravidez , Prevalência , Venezuela/epidemiologiaRESUMO
BACKGROUND: 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. METHODS: In this randomized, double-blind, placebo-controlled trial, 2207 infants received three oral doses of the quadrivalent rotavirus vaccine (4x10(5) plaque-forming units per dose) or placebo at about two, three, and four months of age. During approximately 19 to 20 months of passive surveillance, episodes of gastroenteritis were evaluated at the hospital. RESULTS: The vaccine was safe, although 15 percent of the vaccinated infants had febrile episodes (rectal temperature, > or =38.1 degrees C) during the six days after the first dose, as compared with 7 percent of the controls (P<0.001). However, the vaccine gave 88 percent protection against severe diarrhea caused by rotavirus and 75 percent protection against dehydration, and produced a 70 percent reduction in hospital admissions. Overall, the efficacy of the vaccine against a first episode of rotavirus diarrhea was 48 percent. Horizontal transmission of vaccine virus was demonstrated in 15 percent of the vaccine recipients and 13 percent of the placebo recipients with rotavirus-positive diarrhea. CONCLUSIONS: In this study in a developing country, the quadrivalent rhesus rotavirus-based vaccine induced a high level of protection against severe diarrheal illness caused by rotavirus.
Assuntos
Diarreia Infantil/prevenção & controle , Infecções por Rotavirus/prevenção & controle , Vacinas contra Rotavirus , Vacinas Virais , Anticorpos Antivirais/sangue , Desidratação/etiologia , Desidratação/prevenção & controle , Países em Desenvolvimento , Diarreia Infantil/complicações , Diarreia Infantil/virologia , Transmissão de Doença Infecciosa , Método Duplo-Cego , Feminino , Hospitalização , Humanos , Lactente , Masculino , Rotavirus/classificação , Rotavirus/imunologia , Infecções por Rotavirus/complicações , Infecções por Rotavirus/transmissão , Venezuela , Vacinas Virais/efeitos adversos , Vacinas Virais/imunologiaRESUMO
To 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. coli, enteroinvasive E. coli, and enterohemorrhagic E. coli) and their correlation with O:H serotypes. E. coli isolates exhibiting localized and aggregative adherence in the HEp-2 cell assay were significantly more frequently isolated from the patients (8.5 and 26.9%, respectively) than from the controls (1.7 and 15%, respectively). This difference was significant for the group 0 to 2 months of age but for older infants. Regardless of age, E. coli isolates with diffuse adherence were found at similar frequencies in both the patients and the controls. A striking correlation between classic O serogroups and localized adherence was also observed. These findings confirm the pathogenic role of E. coli with localized and aggregative adherence in diarrheal disease, as well as the epidemiological importance of O:H serotyping for characterizing localized-adhering E. coli.
Assuntos
Aderência Bacteriana , Diarreia Infantil/microbiologia , Escherichia coli/fisiologia , Doença Aguda , Fatores Etários , Linhagem Celular , Diarreia Infantil/epidemiologia , Diarreia Infantil/fisiopatologia , Humanos , Lactente , Venezuela/epidemiologiaRESUMO
Information 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.
Assuntos
Infecções por Rotavirus/epidemiologia , Pré-Escolar , Desidratação/epidemiologia , Diarreia/epidemiologia , Gastroenterite/epidemiologia , Hospitalização , Humanos , Incidência , Lactente , Venezuela/epidemiologiaRESUMO
Some aspects of rotavirus humoral immunity were assessed on the basis of distinguishing serotype-specific specificities (VP4/VP7) by using rotavirus reassortants, human and animal strains in neutralization assays in serum samples obtained during the acute phase, and 1, 6 and 12 months after primary natural infection. In this study, all the infecting virus strains were characterized as G type and some also as P type. Primary natural infection induces a significantly greater homotypic neutralization response than heterotypic response. In addition, there was no significant difference in the number of homotypic or heterotypic responses following reinfection. Transplacentally acquired homotypic antibodies were associated with protection against dehydration during rotavirus gastroenteritis.
Assuntos
Anticorpos Antivirais/sangue , Antígenos Virais , Proteínas do Capsídeo , Gastroenterite/imunologia , Imunoglobulina A/sangue , Infecções por Rotavirus/imunologia , Rotavirus/imunologia , Doença Aguda , Animais , Formação de Anticorpos , Capsídeo/imunologia , Linhagem Celular , Desidratação/imunologia , Desidratação/virologia , Fezes/virologia , Seguimentos , Gastroenterite/virologia , Humanos , Lactente , Macaca mulatta , Rotavirus/isolamento & purificação , Infecções por Rotavirus/virologiaRESUMO
We report the identification of rotavirus in stools of newborn infants at the "Hospital Materno Infantil de Caricuao" (HMIC) as well as the infants' serological responses to various rotavirus strains. The serological responses of another group of rotavirus-positive neonates studied previously at the "Maternidad Concepcion Palacios" (MCP) hospital was also evaluated. Fifty-four of 266 (20%) newborns examined at HMIC shed rotavirus. The infection rate was higher among infants admitted to the nursery (75%) than in those "rooming in" with their mothers (7%) (P < .01). Eleven of the 54 neonates (20%) had diarrhea; seven of them experienced mild, short-lived episodes, whereas five had frequent diarrhea bouts or diarrhea lasting for over 3 days; the remaining 43 infants were asymptomatic. Twenty-seven of 28 rotavirus specimens tested at HMIC had VP7 serotype 4 specificity and one belonged to VP7 serotype 1; VP4 typing performed on 24 of the viruses by RNA hybridization showed these viruses to be similar to the M37 strain, a rotavirus previously associated with asymptomatic infections in newborns at MCP. IgA seroresponses were detected in eight of 11 infants born at HMIC (73%), but most failed to developed neutralization responses to homologous or heterologous strains. Newborn infants who had shed the M37 rotavirus strain at MCP reacted similarly: 16 of 24 (67%) developed a rotavirus IgA rise, but only 29% developed a neutralization response.
Assuntos
Anticorpos Antivirais/sangue , Infecções por Rotavirus/imunologia , Rotavirus/imunologia , Colostro/imunologia , Fezes/microbiologia , Feminino , Sangue Fetal , Humanos , Immunoblotting , Imunoglobulina A/sangue , Recém-Nascido , Testes de Neutralização , Hibridização de Ácido Nucleico , Berçários Hospitalares , Gravidez , RNA Viral/análise , Rotavirus/classificação , Rotavirus/isolamento & purificação , Infecções por Rotavirus/epidemiologia , Infecções por Rotavirus/microbiologia , Sorotipagem , Venezuela/epidemiologia , Eliminação de Partículas ViraisRESUMO
The temporal distribution and clinical severity of rotavirus VP7 serotypes 1, 2, 3, and 4 recovered from 427 Venezuelan children with acute gastroenteritis over a period of 11 years were studied. Rotavirus VP7 serotype was established by ELISA serotyping in 298 (69.78%) of the specimens while the serotype of the remaining 129 (30.21%) samples could not be determined. Of the specimens typed, 85 (19.90% of the total) were serotype 1, 43 (10.07%) were serotype 2, 105 (24.59%) were serotype 3, and 65 (15.22%) were serotype 4. Yearly changes in the frequency of individual serotypes were observed. The predominance of a single serotype with minor contribution from others was noted every year. In this study, serotype 1 appears to induce a less severe illness in comparison with serotypes 2, 3, and 4. No apparent association between the proportion of each serotype and the children's age were found.
Assuntos
Antígenos Virais , Proteínas do Capsídeo , Capsídeo/imunologia , Gastroenterite/microbiologia , Infecções por Rotavirus/microbiologia , Rotavirus/classificação , Pré-Escolar , Ensaio de Imunoadsorção Enzimática , Fezes/microbiologia , Humanos , Lactente , Rotavirus/isolamento & purificação , Sorotipagem , Fatores de Tempo , VenezuelaRESUMO
The significance of rotavirus as an agent in acute diarrhea in children is well established, and much effort has been made towards the development of a vaccine for its prevention. In Venezuela, between the years 1985 and 1991, 3 different strategies for a rotavirus vaccine testing in children have been evaluated. The first consisted on the utilization of simian rotavirus (RRV-ser 3). This vaccine was found to be innocuous, immunogenic and induced homotypic protection. However, because there are 4 epidemiologically important virus serotypes, a new strategy was evaluated. This used a reassortant virus that had 10 genes from the simian viral genome and 1 from the human viral genome, that designated the serotype. Three different reassortants with serotypes 1, 2 and 4 were obtained. The studies with these new viruses demonstrated them to be innocuous but, apparently, the immunogenicity was lower when the four serotypes were mixed in a quadrivalent vaccine than when they were applied individually, or in bivalent vaccines. In consequence, a third strategy was tested, using a virus, M37, isolated from a newborn child. This has the advantage with respect to others, that it is from human origin. However the levels of seroresponse to this virus were no very different from those obtained with the quadrivalent vaccine. At the present time, higher concentrations of the quadrivalent vaccine, in 3 doses, are being applied. We hope to develop ta greater response in these children. If this is achieved, we will then evaluate the efficacy of the vaccine to determine the protection against most severe cases of rotavirus diarrhea.
Assuntos
Diarreia Infantil/prevenção & controle , Infecções por Rotavirus/prevenção & controle , Rotavirus/imunologia , Vacinas Virais , Pré-Escolar , Diarreia Infantil/epidemiologia , Humanos , Lactente , Recém-Nascido , Microscopia Eletrônica , Rotavirus/ultraestrutura , Infecções por Rotavirus/imunologia , Fatores Socioeconômicos , Venezuela/epidemiologia , Proteínas Virais/imunologiaRESUMO
We studied 108 children between 3 and 36 months of age with acute diarrhea and dehydration when their diarrhea continued more than 24 hours following initiation of ORT and in whom we measured pH and glucose of stools with strips in all evacuations. According to the average stool pH and glucose in the first six hours, the patients were grouped in pH < or = 5.5 and > 5.5 and a glucose < or = 1+ and > 1+. The pH of stools < or = 5.5 increased significantly (P < or = .0005) in children between > 6-12 hours and by 48 hours, it was similar to those with an initial average pH 6.6 Stool glucose declined considerably between > 12 and 24 hours. Contrary to what we expected to find, children with pH > 5.5 excreted more stools and had a higher ORT intake in the first 24 hours. The systematic studies of pH and glucose of stools did not appear to be useful for children with acute diarrhea who had a satisfactory evolution.
Assuntos
Diarreia Infantil/terapia , Fezes/química , Hidratação , Concentração de Íons de Hidrogênio , Doença Aguda , Peso Corporal , Pré-Escolar , Método Duplo-Cego , Glucose/administração & dosagem , Humanos , Lactente , Fatores de TempoRESUMO
BACKGROUND AND METHODS: The healthy members of a community represent its largest reservoir of bacteria resistant to antimicrobial agents. We compared the resistance to eight agents of Escherichia coli in stool samples from untreated, healthy children in cities on three continents. RESULTS: When screened by a selective method that detected 1 resistant colony in 10,000 colonies, nearly half the children in Boston (18 of 39) had no resistant colonies--a finding consistent with the findings of other surveys performed in developed countries. However, all but 1 of 41 children screened in Caracas, Venezuela, and all but 2 of 53 in Qin Pu, China, carried resistant strains. Only 1 child in Boston but 25 in Caracas and 34 in Qin Pu carried strains resistant to trimethoprim. None of the children in Boston or Caracas but 17 in Qin Pu carried strains resistant to gentamicin. Among 10 colonies selected randomly from each stool sample, the average frequency of resistance in Caracas was 3.6 times greater than in Boston, and that in Qin Pu was 5.3 times greater. There was resistance to five or more antimicrobial agents in 20 percent of the Qin Pu strains and in 6 percent of the Caracas strains but in none of the Boston strains. CONCLUSIONS: In addition to clinical isolates, as reported previously, the bacteria that colonize health children in the community may be resistant far more often in some regions than in others. A low rate of carriage of antimicrobial resistance in the community should become a public health goal.
Assuntos
Escherichia coli/efeitos dos fármacos , Antibacterianos/farmacologia , Boston , Portador Sadio/microbiologia , Criança , Pré-Escolar , China , Escherichia coli/isolamento & purificação , Fezes/microbiologia , Gentamicinas/farmacologia , Humanos , Lactente , Testes de Sensibilidade Microbiana , Trimetoprima/farmacologia , VenezuelaRESUMO
Phase I studies of an oral quadrivalent rotavirus vaccine were conducted in 130 Venezuelan infants 10 to 20 weeks of age. The vaccine consists of a mixture of equal amounts of rhesus rotavirus (RRV) vaccine (serotype 3 [VP7]) and each of three human rotavirus-RRV reassortant strains: D x RRV (serotype 1 [VP7]), DS1 x RRV (serotype 2 [VP7]), and ST3 x RRV (serotype 4 [VP7]). Three different doses of the quadrivalent vaccine (0.25 x 10(4), 0.5 x 10(4), and 10(4) PFU of each component) were evaluated sequentially for safety and antigenicity in placebo-controlled, double-blind trials. Starting the day after vaccination, the infants were monitored by daily home visits for 7 days. Only minor reactions were observed during this period; these were limited to mild transient febrile episodes which began day 2 or 3 after vaccination and lasted 1 to 2 days in 15 to 30% of the infants. Serological studies demonstrated that 68 to 96% of the infants developed a rotavirus serum immunoglobulin A response following vaccination. However, when tested by plaque reduction neutralization assay against individual human rotavirus serotype 1, 2, 3, or 4, the response rates ranged from 4 to 23% with the low dose, 21 to 33% with the medium dose, and 32 to 58% with the high dose. Most (73 to 79%) infants developed neutralizing antibodies to RRV following administration of each dose schedule. Vaccine virus shedding was analyzed by utilizing tissue culture isolation of virus from stool. All of the infants who received the lower of medium dose and 89% of those fed the high dose shed one or more components of the vaccine. Analyses of rotavirus serotypes isolated from the stool of infants who received the 0.25 x 10(4) -PFU dose revealed that DS1 x RRV was the most commonly shed vaccine component, followed by RRV, D x RRV, and ST3 x RRV in that order.