RESUMO
The present study aimed to provide a molecular characterization of circulating rotavirus (RVA) strains in Rio Branco, Acre, in the post-rotavirus vaccination period, particularly with regard to the emerging, increasingly prevalent G12P[8] genotype. A total of 488 fecal specimens from diarrheic and non-diarrheic children were obtained between January and December 2012. RVA detection was initially performed using enzyme-linked immunosorbent assay (ELISA) method, followed by reverse-transcription polymerase chain reaction (RT-PCR) using specific primers. RVA was detected in 18.3% (44/241) of the children with acute diarrhea and in 1.2% (3/247) of the non-diarrheic children (P < 0.001), with overall RVA-positivity of 9.6% (47/488). The most common genotype was G2P[4] with 43.2% (19/44) of the diarrheic cases, followed by G12P[8] (27.3%, 12/44), G3P[6] (18.2%, 8/44), G3P[8] (4.5%, 2/44), and G12P[6] (2.3%, 1/44). G12 samples belonged to lineage III and were from children aged 4-52 months. All of these children had acute diarrhea associated with fever (83.3%, 10/12) and vomiting (66.7%, 8/12). Most of the cases occurred in August (58.3%, 7/12), 75% (9/12) of which having received the full vaccination scheme with Rotarix™. For the first time G12 was reported at relative high prevalence in Brazil. Our findings warrant further monitoring studies on the molecular characterization of circulating RVA strains after rotavirus vaccine introduction in Brazil and elsewhere, since the occurrence of either unusual our emerging genotypes may pose a challenge to vaccination strategies.
Assuntos
Genótipo , Infecções por Rotavirus/epidemiologia , Infecções por Rotavirus/prevenção & controle , Vacinas contra Rotavirus/administração & dosagem , Rotavirus/classificação , Rotavirus/genética , Brasil/epidemiologia , Pré-Escolar , Ensaio de Imunoadsorção Enzimática , Fezes/virologia , Feminino , Humanos , Lactente , Recém-Nascido , Masculino , Epidemiologia Molecular , Prevalência , Reação em Cadeia da Polimerase Via Transcriptase Reversa , Rotavirus/isolamento & purificação , Infecções por Rotavirus/patologia , Infecções por Rotavirus/virologia , Estações do AnoRESUMO
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.
Assuntos
Anticorpos Antivirais/imunologia , Gastroenterite/prevenção & controle , Infecções por Rotavirus/prevenção & controle , Vacinas contra Rotavirus/administração & dosagem , Administração Oral , Anticorpos Antivirais/genética , Pré-Escolar , Método Duplo-Cego , Feminino , Gastroenterite/virologia , Genótipo , Humanos , Lactente , Masculino , Infecções por Rotavirus/virologia , Vacinas contra Rotavirus/efeitos adversos , Vacinas contra Rotavirus/imunologia , Índice de Gravidade de Doença , Vacinas Atenuadas/administração & dosagem , Vacinas Atenuadas/efeitos adversos , Vacinas Atenuadas/imunologiaRESUMO
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.
Assuntos
Pré-Escolar , Feminino , Humanos , Lactente , Masculino , Anticorpos Antivirais/imunologia , Gastroenterite/prevenção & controle , Infecções por Rotavirus/prevenção & controle , Vacinas contra Rotavirus/administração & dosagem , Administração Oral , Anticorpos Antivirais/genética , Método Duplo-Cego , Genótipo , Gastroenterite/virologia , Infecções por Rotavirus/virologia , Vacinas contra Rotavirus/efeitos adversos , Vacinas contra Rotavirus/imunologia , Índice de Gravidade de Doença , Vacinas Atenuadas/administração & dosagem , Vacinas Atenuadas/efeitos adversos , Vacinas Atenuadas/imunologiaRESUMO
Noroviruses, a major cause of acute gastroenteritis outbreaks worldwide, are constantly evolving. This ability is reflected in the speed and efficiency with which these viruses spread and remain in the human population. The present study reports the detection of a novel recombination event among norovirus genotypes in Brazil in 2008. A strain detected in a stool sample from a child with norovirus-associated gastroenteritis, residing in an African-descendant semi-closed community of Pará State, was characterized as a novel intergenotype recombinant, GII.7/GII.20, as determined by partial sequencing and SimPlot analysis.
Assuntos
População Negra , Infecções por Caliciviridae/virologia , Gastroenterite/virologia , Norovirus/classificação , Norovirus/genética , Vírus Reordenados , Sequência de Bases , Brasil/epidemiologia , Infecções por Caliciviridae/epidemiologia , Fezes/virologia , Gastroenterite/epidemiologia , Humanos , Lactente , Dados de Sequência Molecular , FilogeniaRESUMO
To study enteropathogens, 100 fecal samples were collected from a Brazilian human immunodeficiency virus (HIV)-seropositive population, with or without diarrhea. Giardia lamblia and calicivirus were significantly associated with diarrhea as were severe immunosuppression and the presence of at least one enteropathogen. No sample was positive for rotavirus and only one asymptomatic individual carried the astrovirus. We concluded that there is a great diversity of pathogens and opportunistic infections in the studied population, with a high prevalence of mixed colonization/infection. Our findings pave the way for future molecular studies related to the expression of virulence factors and to the possibility of pathogen-pathogen interactions, especially between G. lamblia and calicivirus. These findings are relevant to the improvement of therapies and controlling diarrhea in the HIV-seropositive population.
Assuntos
Infecções por Caliciviridae/complicações , Diarreia/parasitologia , Diarreia/virologia , Giardíase/complicações , Infecções por HIV/complicações , HIV , Adulto , Animais , Brasil/epidemiologia , Caliciviridae/isolamento & purificação , Infecções por Caliciviridae/epidemiologia , Feminino , Giardia lamblia/isolamento & purificação , Giardíase/epidemiologia , Infecções por HIV/epidemiologia , Soropositividade para HIV , Humanos , MasculinoRESUMO
The prevalence and potential zoonotic transmission of group C rotavirus (RVC) were examined by testing fecal samples collected from children during a longitudinal study that was carried out in the outskirts of Belém, Brazil, from December 1982 to March 1986. The study involved a group of 30 children who were followed from birth to 3 years. Of the 77 samples tested from 29 children, 5 (6.5%) were positive for human and 3 (4%) for porcine RVC by using nested PCR assay with primers specific for VP6 gene of human or porcine RVC and by Southern hybridization using a probe specific for VP6 gene of both human and porcine RVC. In addition, a total of 59 fecal specimens from the 30th child were tested, 1 (1.7%) and 14 (23.7%) were positive for human and porcine RVC, respectively. Partial nucleotide sequences of VP6 gene demonstrated that the six human strains detected in Brazil were homologous with other human RVC, and 14 of the 17 porcine RVC strains examined showed a complete homology among themselves but differed slightly from the porcine Cowden strain, suggesting that a single porcine RVC strain was circulating in Belém. This study is the first to provide evidence for transmission of RVC from swine to human. They also indicate that both human and porcine RVC were endemic in Belém.
Assuntos
Infecções por Rotavirus/transmissão , Rotavirus/classificação , Rotavirus/isolamento & purificação , Zoonoses/transmissão , Zoonoses/virologia , Animais , Antígenos Virais/genética , Southern Blotting/métodos , Brasil/epidemiologia , Proteínas do Capsídeo/genética , Pré-Escolar , Primers do DNA/genética , Fezes/virologia , Humanos , Lactente , Recém-Nascido , Estudos Longitudinais , Epidemiologia Molecular , Dados de Sequência Molecular , Filogenia , Reação em Cadeia da Polimerase/métodos , Rotavirus/genética , Infecções por Rotavirus/epidemiologia , Análise de Sequência de DNA , Homologia de Sequência do Ácido Nucleico , Doenças dos Suínos/virologia , Zoonoses/epidemiologiaRESUMO
Human astroviruses (HAstV) are worldwide recognized as important viral enteropathogens during childhood. This study aims to determine the incidence, genetic diversity and intertype variability of HAstV-1 in children less than 5 years of age enrolled in several studies conducted in Belém/Pará, and São Luís/Maranhão, Brazil, from December 1982 to May 2000. Using EIA and RT-PCR, an overall positivity of 6.1% (155/2.534) was achieved, of these, 140 were positive by RT-PCR. The analysis of a 348bp ORF2 fragment revealed that HAstV-1 was the predominant genotype (85/140, 60.7%) throughout the 18 years of study. Phylogenetic analysis was performed for 81 of these strains, and 76 (93.8%) were genetically classified as HAstV-1a. The remainder of strains (n=5) were assigned to possible new lineages, 1e and 1f. Four of these five strains were detected in 1983 and 1984, and the lineage 1a circulated during 10 consecutive years (1990/2000). Genome sequence variation was found among the HAstV-1 strains involving all lineages, but only five nucleotide changes translated into aminoacid changes over this period, suggesting that HAstV-1 was very stable. The data obtained in this study should be useful for further studies at molecular level, including improvement of disease surveillance based on molecular diagnostic tools, and vaccine development.
Assuntos
Infecções por Astroviridae/epidemiologia , Infecções por Astroviridae/virologia , Gastroenterite/epidemiologia , Gastroenterite/virologia , Mamastrovirus/genética , Epidemiologia Molecular , Sequência de Bases , Brasil/epidemiologia , Pré-Escolar , Diarreia Infantil/epidemiologia , Diarreia Infantil/virologia , Variação Genética , Genótipo , Humanos , Lactente , Recém-Nascido , Mamastrovirus/classificação , Mamastrovirus/isolamento & purificação , Dados de Sequência Molecular , FilogeniaRESUMO
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% were detected, and in ORF2 96-99%. Considering the sequence variation (7%) observed in ORF2 region, it was suggested that HAstV-8 strains could be divided in three different lineages.
Assuntos
Infecções por Astroviridae/virologia , Diarreia Infantil/virologia , Mamastrovirus/genética , Infecções por Astroviridae/epidemiologia , Brasil/epidemiologia , Diarreia Infantil/epidemiologia , Fezes/virologia , Feminino , Humanos , Lactente , Mamastrovirus/classificação , Mamastrovirus/isolamento & purificação , Fases de Leitura Aberta , Reação em Cadeia da Polimerase Via Transcriptase ReversaRESUMO
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.
Assuntos
Humanos , Feminino , Lactente , Infecções por Astroviridae/virologia , Diarreia Infantil/virologia , Mamastrovirus/genética , Infecções por Astroviridae/epidemiologia , Brasil/epidemiologia , Diarreia Infantil/epidemiologia , Fezes/virologia , Mamastrovirus/classificação , Mamastrovirus/isolamento & purificação , Fases de Leitura Aberta , Reação em Cadeia da Polimerase Via Transcriptase ReversaRESUMO
OBJETIVO: Determinar a segurança, imunogenicidade e eficácia de duas doses da vacina contra o rotavírus em lactentes brasileiros saudáveis. MÉTODOS: Foi realizado um estudo randomizado, multicêntrico, duplo-cego e controlado por placebo no Brasil, México e Venezuela. Os lactentes receberam duas doses orais de vacina ou placebo aos 2 e 4 meses de idade, juntamente com as imunizações de rotina, exceto a vacina oral contra poliomielite (VOP). O presente estudo relata apenas os resultados obtidos em Belém, Brasil, onde o número de indivíduos por grupo e os títulos da vacina viral foram os seguintes: 194 (104,7 unidades formadoras de focos - UFF), 196 (10(5,2) UFF), 194 (10(5,8) UFF) e 194 (placebo). A resposta de anticorpos anti-rotavírus (anti-RV) foi avaliada em 307 indivíduos. A gravidade clínica dos episódios de gastroenterite (GE) foi determinada através de um escore com 20 pontos, onde um valor > 11 foi considerado como GE grave. RESULTADOS: As taxas de sintomas gerais solicitados foram semelhantes tanto nos indivíduos que receberam a vacina como naqueles a quem se administrou placebo. Aos 2 meses após a segunda dose, ocorreu resposta em termos de IgA sérica para RV em 54,7 a 74,4 por cento dos vacinados. Não houve interferência na imunogenicidade das vacinas de rotina. A eficácia da vacina contra qualquer gastroenterite por rotavírus (GERV) foi de 63,5 por cento (IC95 por cento 20,8-84,4) para a maior concentração (10(5,8) UFF). A eficácia foi de 81,5 por cento (IC95 por cento 44,5-95,4) contra GERV grave. Em sua maior concentração (10(5,8) UFF), a RIX4414 conferiu uma proteção de 79,8 por cento (IC95 por cento 26,4-96,3) contra GERV grave causada pela amostra G9. CONCLUSÕES: A RIX4414 foi altamente imunogênica com baixa reatogenicidade, e não interferiu na resposta sérica à difteria, tétano, coqueluche, hepatite B e antígenos Hib. Duas doses da RIX4414 conferiram proteção significativa contra a GE grave causada pelo RV.
OBJECTIVE: To determine the safety, immunogenicity and efficacy of two doses of rotavirus vaccine in healthy Brazilian infants. METHODS: A randomized, multicenter, double-blind, placebo-controlled trial was conducted in Brazil, Mexico and Venezuela. Infants received two oral doses of vaccine or placebo at 2 and 4 months of age, concurrently with routine immunizations, except for oral poliomyelitis vaccine (OPV). This paper reports results from Belém, Brazil, where the number of subjects per group and the viral vaccine titers were: 194 (10(4.7) focus forming units - FFU), 196 (10(5.2) FFU), 194 (10(5.8) FFU) and 194 (placebo). Anti-rotavirus (anti-RV) antibody response was assessed in 307 subjects. Clinical severity of gastroenteritis episodes was measured using a 20-point scoring system with a score of > 11 defined as severe GE. RESULTS: The rates of solicited general symptoms were similar in vaccine and placebo recipients. At 2 months after the second dose, a serum IgA response to RV occurred in 54.7 to 74.4 percent of vaccinees. No interference was seen in the immunogenicity of routine vaccines. Vaccine efficacy against any rotavirus gastroenteritis (RVGE) was 63.5 percent (95 percentCI 20.8-84.4) for the highest concentration (10(5.8) FFU). Efficacy was 81.5 percent (95 percentCI 44.5-95.4) against severe RVGE. At its highest concentration (10(5.8) FFU), RIX4414 provided 79.8 percent (95 percentCI 26.4-96.3) protection against severe RVGE by G9 strain. CONCLUSIONS: RIX4414 was highly immunogenic with a low reactogenicity profile and did not interfere with seroresponse to diptheria, tetanus, pertussis, hepatitis B and Hib antigens. Two doses of RIX4414 provided significant protection against severe GE caused by RV.