RESUMO
A 4-year (2005-2008) norovirus (NoV) surveillance study was conducted in the state of Rio Janeiro, Brazil, to demonstrate the role of these viruses in outbreaks and sporadic cases of acute gastroenteritis. A cohort of 1,687 fecal samples was obtained from patients with gastroenteritis; 324 were rotavirus-positive. Of the remainder 1,363 rotavirus-negative samples, 1,087 samples were tested for NoV RNA in this study. The study enrolled 267 outpatients from Municipal Public Health Centers and 820 inpatients, whose samples were obtained by active surveillance in Public Hospitals. Fecal samples were tested by reverse transcription (RT) followed by polymerase chain reaction (PCR) using the MON 431-434 set of degenerate primers for NoV GI and GII detection, and there were 35.1% (381/1,087) positive samples for NoV, consisting of 30.2% (248/820) and 49.8% (133/267) from inpatient and outpatient, respectively. Children infected by NoV had significantly more frequent mucus in feces, vomiting and fever. No seasonal pattern in NoV infections was observed in patients admitted to hospital; however, two peaks of NoV infections were observed from ambulatory cases, suggesting that there was an occurrence of outbreaks in those time periods. Molecular characterization revealed GII to be the most prevalent genogroup, totaling 96.3% (104/108) of all sequences analyzed, and GII.4 was the genotype detected most frequently (80.7%), followed by GII.6, 3, 14, 7, and 8. Two GI strains, GI.2 and GI.3, were also observed. The number of outbreaks and sporadic cases described in this study highlights the need to implement diagnosis of NoV in surveillance laboratories.
Assuntos
Infecções por Caliciviridae/epidemiologia , Gastroenterite/epidemiologia , Norovirus/isolamento & purificação , Adolescente , Adulto , Idoso , Idoso de 80 Anos ou mais , Brasil/epidemiologia , Infecções por Caliciviridae/patologia , Infecções por Caliciviridae/virologia , Criança , Pré-Escolar , Primers do DNA/genética , Surtos de Doenças , Fezes/virologia , Feminino , Gastroenterite/patologia , Gastroenterite/virologia , Genótipo , Humanos , Lactente , Recém-Nascido , Masculino , Pessoa de Meia-Idade , Dados de Sequência Molecular , Norovirus/classificação , Norovirus/genética , RNA Viral/genética , Reação em Cadeia da Polimerase Via Transcriptase Reversa , Rotavirus/isolamento & purificação , Análise de Sequência de DNA , Adulto JovemRESUMO
Group A rotaviruses (RV-A) are the major cause of gastroenteritis in infants and young children around the world. Each year RV-A causes approximately 11 million episodes of severe diarrhea, with an estimated of 611,000 deaths. Epidemiologic surveys have identified P[8]G1, P[4]G2, P[8]G3, P[8]G4, and P[8]G9 as the most common global genotypes associated with diarrhea in children up to 5-year old. Surveillance studies and documentation of RV-A G and P genotypes is necessary for a comprehensive evaluation of the evolution of new strains, and assessing the capability of vaccines to provide heterotypic protection. It is known that reassortments are the driving force for genetic diversity through sudden changes in RV-A genome. In this study, we identified two unusual P/G combinations, P[8]G8 and P[4]G8, occurring in Rio de Janeiro during 2002. Results obtained in this study suggest that P[8]G8 RV-A strain originated from a reassortment event that occurred between RV-A P[4]G8 and P[8]G9 strains circulating in Rio de Janeiro in the same year. G8 strains identified in this study, as well as G8 strains detected in Recife by Montenegro et al. [Montenegro et al. (2007) J Med Virol 79: 335-340], showed a close genetic relationship with strains from Africa, where this genotype have become prevalent.
Assuntos
Diarreia/epidemiologia , Vírus Reordenados/isolamento & purificação , Infecções por Rotavirus/epidemiologia , Rotavirus/isolamento & purificação , Brasil/epidemiologia , Diarreia/virologia , Humanos , Epidemiologia Molecular , Filogenia , RNA Viral/genética , Vírus Reordenados/classificação , Vírus Reordenados/genética , Rotavirus/classificação , Rotavirus/genética , Infecções por Rotavirus/virologia , População UrbanaAssuntos
Doenças do Cão/virologia , Fezes/virologia , Picobirnavirus/isolamento & purificação , Infecções por Vírus de RNA/veterinária , RNA Viral/isolamento & purificação , Animais , Cães , Eletroforese em Gel de Ágar/veterinária , Picobirnavirus/genética , Infecções por Vírus de RNA/virologia , RNA Viral/genéticaRESUMO
Human rotavirus strains belonging to genotype G9 or P[9] were detected in a collection of stool specimens from children with diarrhea in two cities of the state of Rio de Janeiro, Brazil, between March 1997 and December 1999. G9 strains were first detected in April 1997 and remained prevalent until the end of the study, at a frequency of 15.9% (n = 157). A high percentage of VP7 nucleotide (99.0 to 99.5%) and deduced amino acid identity (98.6 to 99.1%) was found between three randomly selected Brazilian G9 strains and the American G9 strain US1205. A novel G9:P[4] genotype combination was detected in addition to G9:P[8] and G9:P[6], demonstrating that this G genotype may undergo constant genetic reassortment in nature. The P[9] rotavirus strains constituted 10.2%, the majority of which were detected between April and July 1997. The RNA electrophoretic migration pattern of the G3:P[9] strains resembled that of AU-1 virus (G3:P3[9]), suggesting a genetic similarity between the Brazilian G3:P[9] strains and the Japanese virus, which is similar to a feline rotavirus genetically.