Oral live attenuated human rotavirus vaccine (RotarixTM) offers sustained high protection against severe G9P[8] rotavirus gastroenteritis during the first two years of life in Brazilian children

In a large Phase III trial conducted in 10 Latin American countries, the safety and efficacy of the live attenuated monovalent rotavirus vaccine RIX4414 was evaluated in 15,183 healthy infants followed up during the first two years of life. Belém was the only site in Brazil included in this multicentre trial. The study in Belém included a subset of 653 infants who were followed up until 24 months of age for protection against severe rotavirus gastroenteritis. These subjects were randomly assigned in a 1:1 ratio to receive two doses of vaccine (n = 328) or two doses of placebo (n = 325) at approximately two and four months of age. Of the 653 enrolled infants, 23 dropped out during the study period. For the combined two-year period, the efficacy of RIX4414 was 72.3% [95% confidence interval (CI) 37.5-89.1%] against severe rotavirus-related gastroenteritis, reaching a protection rate of 81.8% (95% CI 36.4-96.6%) against circulating wild-type G9 rotavirus strains. It is concluded that two doses of RIX4414 are highly efficacious against severe rotavirus gastroenteritis in Belém during the first two years of life and provide high protection against the worldwide emergence and spread of G9P[8] strains.

First detection of a human astrovirus type 8 in a child with diarrhea in Belém, Brazil: comparison with other strains worldwide and identification of possible three lineages

This study describes the genetic relationships of the first human astrovirus type-8 (HAstV-8) detected in Belém-Brazil, during a public hospital-based study. This strain was compared with other HAstV-8 strains identified elsewhere which have sequences available at GeneBank. The regions ORF1a (primers Mon348/Mon340) and ORF2 (primers Mon269/Mon270) were analyzed by nucleotide sequencing and a high similarity rate was observed among the Belém strain and other HAstV-8 strains. In ORF1a, homology values of 93-100 por cento were detected, and in ORF2 96-99 por cento. Considering the sequence variation (7 por cento) observed in ORF2 region, it was suggested that HAstV-8 strains could be divided in three different lineages.

Prevalence and genetic diversity of astroviruses in children with and without diarrhea in São Luís, Maranhão, Brazil

Human astroviruses (HAstV) have been increasingly identified as important etiological agents of acute gastroenteritis in children up to five years old. The aim of this study was to determine the prevalence and genotype diversity of HAstV in children with symptomatic and asymptomatic infections in São Luís, Maranhão, Brazil. From June 1997 to July 1999 a total of 183 fecal samples 84 from symptomatic and 99 from asymptomatic children were tested by enzyme immunoassay for HAstV. Prevalence rates were found to be 11 and 3 percent for symptomatic and asymptomatic children, respectively. Reverse transcription-polymerase chain reaction (RT-PCR) was carried out in 46 specimens (26 symptomatic and 20 asymptomatic) including the 12 samples that were positive by enzyme immunoassay (EIA). The overall positivity yielded by both methods was 8 percent (15/184); of these, 11 percent (9/84) for symptomatic and 5 percent (5/99) for those without symptoms or signs. Sequence analysis of amplicons revealed that HAstV-1 genotype was the most prevalent, accounting for 60 percent of isolates. Genotypes 2, 3, 4, and 5 were also detected, as one single isolate (10 percent) for each type. Variations in the sequences were observed when Brazilian isolates were compared to prototype strains identified in the United Kingdom. No seasonal pattern of occurrence was observed during these two years of study, and peak detection rate was observed in children aged between 3 and 6 months in the symptomatic group, and between 18 and 24 months in the controls.

Rotavirus serotypes and electropherotypes identified among hospitalised children in São Luís, Maranhão, Brazil

De junho de 1997 a junho de 1999, pesquisou-se a infecção por rotavírus entre crianças até 2 anos de idade internadas com quadro diarréico agudo em São Luís, nordeste do Brasil. Coletaram-se 128 espécimes fecais oriundos de pacientes diarréicos. Paralelamente, obtiveram-se 122 amostras de um contingente caracterizado como controle, comparável ao anterior no tocante às idades e distribuição temporal. As freqüências de positividade para rotavírus alcançaram 32,0 por cento (41/128) e 9,8 por cento (12/122), respectivamente (p < 0,001). Procedeu-se à determinação dos sorotipos e eletroferotipos dos rotavírus em 42 (79,2 por cento) das 53 amostras reativas para rotavírus. Identificaram-se eletroferotipos longo e curto em freqüências similares - 38,1 por cento e 40,5 por cento, respectivamente. De um modo geral, caracterizou-se o sorotipo G em 35 (83,3 por cento) das amostras positivas, a maioria, revelando especificidade para o tipo G1. Considerando o conjunto dos eletroferotipos e sorotipos, rotavírus classificados como G1 exibiram padrões eletroforéticos longo e curto nas freqüências de 30,9 por cento e 19 por cento, respectivamente. Todos os rotavírus do tipo G2 apresentaram eletroferotipo de configuração curta. No tocante ao perfil temporal, observou-se que as gastroenterites por rotavírus naquela região ocorrem ao longo de todo o ano, denotando-se tendência quanto à mais expressiva concentração no segundo semestre de vida das crianças, se comparado ao primeiro; em síntese, 45,2 por cento e 26,1 por cento (p = 0,13), respectivamente. As infecções por rotavírus configuraram picos quanto à distribuição durante o segundo semestre de vida, com freqüências de 30,1 por cento e 13,5 por cento, respectivamente. Aqueles do tipo G2 circularam durante todo o período de estudo, enquanto o sorotipo G1 (n = 27) emergiu a partir de junho de 1998. Aliás, detectaram-se 20 (74,1 por cento) das amostras virais com essa última especificidade ao longo de 1998. Os dados acima sustentam a importância dos rotavírus na etiologia das gastroenterites graves no nordeste brasileiro e consubstanciam o conceito de que uma futura vacina contra esses enteropatógenos necessariamente deve conferir proteção frente aos múltiplos sorotipos circulantes.

Nutritional status in relation to the efficacy of the rhesus-human reassortant, tetravalent rotavirus vaccine (rrv-tv) in infants from Belém, Para state, Brazil

The rhesus-human reassortant, tetravalent rotavirus vaccine (RRV-TV) was licensed for routine use in the United States of America but it was recently withdrawn from the market because of its possible association with intussusception as an adverse event. The protective efficacy of 3 doses of RRV-TV, in its lower-titer (4 x 10(4) pfu/dose) formulation, was evaluated according to the nutritional status of infants who participated in a phase III trial in Belém, Northern Brazil. A moderate protection conferred by RRV-TV was related to weight-for-age Z-scores (WAZ) greater than -1 only, with rates of 38 percent (p = 0.04) and 40 percent (p = 0.04) for all- and- pure rotavirus diarrhoeal cases, respectively. In addition, there was a trend for greater efficacy (43 percent, p = 0.05) among infants reaching an height-for-age Z-score (HAZ) of > -1. Taking WAZ, HAZ and weight-for-height Z-score (WHZ) indices <= -1 together, there was no significant protection (p > 0.05) if both placebo and vaccine groups are compared. There was no significant difference if rates of mixed and pure rotavirus diarrhoeal cases are compared in relation to HAZ, WAZ and weight-for-height Z-score (WHZ) indices. Although a low number of malnourished infants could be identified in the present study, our data show some evidence that malnutrition may interfere with the efficacy of rotavirus vaccines in developing countries

Rotaviruses as a cause of nosocomial, infantile diarrhoea in northern Brazil: pilot study

Faecal samples were obtained from 190 children, aged 0 to 5 years, admitted to a public hospital in Belém, Pará, Brazil. These patients were placed in a pediatric ward with 40 beds distributed in six rooms. Case were classified into three groups: (a) nosocomial: children who developed gastroenteritis 72 hr or later after admission; (b) community-acquired: patients admitted either with diarrhoea or who had diarrhoea within 72 hr following admission; (c) non-diarrhoeic: those children who had no diarrhoea three days before and three days after collection of formed faecal sample. Specimens were routinely processed for the presence of rotaviruses, bacteria and parasites. Rotaviruses were detected through enzyme-linked immunosorbent assay (ELISA) and subsequently serotyped/electrophoretyped. Rotaviruses were the most prevalent enteropathogens among nosocomial cases, accounting for 39 porcento (9/23) of diarrhoeal episodes; on the other hand, rotaviruses ocurred in 8.3 por cento (11/133) and 9 por cento (3/34) of community-acquired and non-diarrhoeic categories, respectively. Mixed infections involving rotavirus and Giardia intestinalis and rotavirus plus G. intestinalis and Entamoeba histolytica were detected in frequencies of 8.6 and 4.3 por cento, respectively, in the nosocomial group. The absence of bacterial pathogens in this category, and the unusual low prevalence of these agents in the other two groups may reflect the early and routine administration of antibiotics following admission to this hospital. Rotavirus serotype 2 prevailed over the other types, accounting for 77.8 por cento of isolates from nosocomial diarrhoeal episodes. In addition, at least five different genomic profiles could be observed, of which one displayed an unusual five-segment first RNA cluster. Dehydration was recorded in all cases of hospital-acquired, rotavirus-associated diarrhoea, whereas in only 57 por cento of nosocomial cases of other aetiology. It was also noted that nosocomial, rotavirus-associated diarrhoeal episodes ocurr earlier (7 days), following admission, if compared with those hospital-acquired cases of other aetiology (14 days).

Síndrome da imunodeficiência adquirida: o que sabem colegiais adolescentes acerca do seu mecanismo de transmissäo / Acquired immunodeficiency syndrome: what adolescent students know about its mechanism of transmission?

Questionários apresentado situaçöes diversas no que concerne aos mecanismos de transmissäo da síndrome da imunodeficiência adquirida (SIDA) foram aplicadas a 298 colegiais - adolescentes em sua totalidade -, sendo 81(27,2%) da rede pública de ensino e 217(72,8%) de escolas privadas na área de Belém, Pará. Paralelamente, e a título de referencial, as mesmas questöes foram submetidas 37 professores atuantes nos colégios sob estudo. O percentual de acertos no primeiro grupo foi de 70,9% e, no segundo, de 82,0%; entre os docentes obtiveram-se respostas corretas em 76,9% das situaçöes apresentadas. As mais expressivas freqüências de erro se associaram ao ato de doar sangue: 54,8% dos participantes responderam que a SIDA pode ser transmitida a alguém no ato de doar sangue a um banco de transfusöes; ainda 57,9% caracterizaram os doadores como um grupo sob alto risco de contrair a infecçäo, comparando-os, mesmo, aos homossexuais e viciados em drogas injetáveis

Pesquisa de anticorpos para o virus da AIDS em parturientes com vida sexual promíscua na área de Belém: estudo piloto / Research of antibodies for AIDS's viruses in parturient with promiscuos sexual life in the area of Belém

Estudaram-se 63 parturientes (entre 800 selecionadas) com história de vida sexual promíscua, quanto a presença de anticorpos para o vírus da AIDS. Utilizando-se método imunoenzimático competitivo ("Wellcozyme ant-HTL III")näo se detectaram amostras de soro positivo no grupo sob estudo. Soros do cordäo umbilical dos recém-natos, embora sistematicamente colhidos, näo foram testados face a total negatividade observada nos espécimes maternos

A possible fifth human rotavirus serotype and an unusual serotype 2, subgroup II rotavirus strains

Uma cepa de rotavírus, obtida de criança diarreica com 22 meses de idade, näo reagiu com anticorpos monoclonais para os quatro sorotipos desse agente, emergindo como um possível novo sorotipo. Essa amostra se caracterizou por pertencer ao subgrupo II, exibindo perfil genômico, por eletroforese em gel de policrilamida, tipicamente longo. Detectou-se, ainda, outra amostra de rotavírus, oriunda de criança com 19 meses de idade, assintomática, com características sorológicas que a classificaram como sorotipo 2, monoclonais. Näo se obtiveram padröes de eletroforese nucleica suficientemente nítidos, bem como näo se logrou a replicaçäo virótica dessa cepa em células da linhagem "MA 104", quer a partir da simples suspensäo de fezes, quer após efetuada a purificaçäo em gradiente de cloreto de césio. Ambos os achados acima referidos decorreram de estudo longitudinal envolvendo 88 crianças, habitantes da área periférica de Belém, observados desde o seu nascimento até os três anos de idade

Pattern of acquisition of rotavirus antibody in children followed up from birth to the age of three years

Nine hundred and forty-eight serum samples from 83 children living in Belem, Brazil, collected within their first three years oflife, were tested for the presence of groupspecific rotavirus-antibody by an enzyme-linked immunosorbent assay (Elisa) blocking-test. Passively transferred maternal antibody lasted about two and half months; subsenquentely, low levels of rotavirus antibody started to appear at seven months, reaching a peak at eleven months of age. From one year onwards positivity gradually increased, reaching highest values at 34 months of life. Individual responses were examined in sera from 61 children who were followed up since birth to three years of age: 38 (62,3%) of them developed a long-term immunity following first infection; eleven (18.0%) children developed a short-term immunity after first infection by rotavirus; seven (11.5%) had no antibody response within their first three years of life; and 5 (8.2%) showed positive antibody response from birth to three years old

Atypical rotavirus among diarrhoeic children living in Belém, Brazil

Rotavírus atípicos foram detectados nas fezes de duas crianças diarreícas residentes em Belém, Brasil. Partículas de rotavírus foram visualizadas por microscopia eletrônica nos espécimes fecais de ambos os pacientes, tendo a eletroforese do ácido ribonucleico (ARN) exibido padröes compatíveis com rotavírus do grupo C. Testes imunoenzimáticos (ELISA) foram negativos quanto a presença de antígenos do grupo A. As duas crianças apresentaram três infecçöes sucessivas por esse agente, sendo que, em ambos os casos, os rotavírus atípicos foram excretados por ocasiäo da terceira infecçäo, produzindo sintomas brandos e de pouca duraçäo

Distribuiçäo temporal de perfis eletrofocéticos de Acido nucleico de rotavírus em fezes de crianças em Belém, Pará / Temporal distribution of rotavirus RNA eletrophoretic prolfiles in Belém, Pará

Amostras de rotavírus provenientes de crianças habitantes na periferia de Belém, Pará, foram analisadas por eletroforese em gel de policrilamida (PAGE). As bandas correspondentes aos 11 segmentos de ARN foram detectadas em 46 (76,7%) das 60 amostras de rotavírus. Das amostras classificadas 5 (109%) foram relativas ao subgrupo I, 41 (89,1%) ao subgrupo II e, em 23,3%) näo foi possível classificaçäo face a ausência das bandas 10 e 11. As amostras de rotavírus sub-grupo II e codificadas como "1N2L" foram as mais freqüentes, ocorrendo em 30 (65,2%) das 46 classificadas

Reinfections and Rotavirus serotypes in Belém, Brazil (preliminary report)

Infecçöes sucessivas causadas por rotavírus foram detectadas em quatro crianças habitantes de Belém, acompanhadas desde seu nascimento até os três anos de idade. Em uma delas (Reg. 23.983) três infecçöes sintomáticas foram observadas, duas por sorotipo näo especificado e outra pelo 2: a primeira aos 4 meses, a segunda aos 20, e a terceira aos 27. Outro indivíduo (Reg. 24.384) apresentou dois episódios diarréico, com intervalo de oito meses, o primeiro sorotipo 1 e o segundo por sorotipo näo identificado. Infecçöes também aparentes foram observadas em duas ocasiöes envolvendo a mesma criança (Reg. 24.004), a primeira por sorotipo 1 e, doze meses após, uma segunda pelo 2. Em uma outra criança (Reg. 24.097) duas infecçöes, ambas inaparentes e por sorotipo näo especificado, foram detectadas: a primeira aos 24 meses de vida e a segunda, aos 28