ABSTRACT
Objective To infer its transmission origin and route through studying the feature of molecular epidemiology of an HCV outbreak in Guangzhou.Methods Serum samples 192 cases in an HCV outbreak incident were analyzed for 2a and 6a subtypes.Appropriate genotypes were selected as control group.Informatics software were used in the evolutionary analysis to construct time scale trees and infer the origin time of HCV infection.Results Of 119 patients in the HCV outbreak,66 cases were 2a and 110 cases were 6a subtype.No other genotypes were found.The evolutionary analysis indicated the isolates of 2a group and 6a group both originated from 2 ～ 5 years ago.Both of 2a group and 6a group were in line with the characteristics of iatrogenic infection.Conclusion 2a and 6a were the main sub-genotypes in the Guangdong HCV outbreak investigation and they were originated from 2 to 5 years ago,which were in line with the characteristics of iatrogenic transmission.With the extension of time,a large number of cases accumulated and led to outbreak.
ABSTRACT
Os vírus Influenza A infectam um largo espectro de hospedeiros e causam epidemias anuais. São vírus com alta variabilidade genética e RNA segmentado, que podem sofrer rearranjos entre os genes de diferentes vírus. Em 2006, foram analisadas 521 amostras de crianças menores de 5 anos atendidas no HU-USP e 25 foram positivas para Influenza A, sendo H3N2 o mais prevalente (68%). Cinco genes de 18 amostras foram seqüenciados e obtivemos 13 sequencias de HA, 12 da NP, 12 de NA, 14 da M e 10 da NS. Verificou-se a presença de várias mutações, especialmente na HA e NA, que favoreceram a substituição da cepa vacinal naquele ano. Todas as amostras H3N2 apresentaram sítios de resistências aos inibidores da M2. Diferentes linhagens circularam no mesmo ano, tanto de H1 como de H3, favorecendo rearranjos entre elas. Foram verificados, também rearranjos envolvendo os genes da HA e NP, indicando o complexo mecanismo de evolução desses vírus e enfatizando a necessidade de monitoramento da circulação e caracterização de seus genes.
Influenza A virus infects a wide range of hosts and cause annual outbreaks. RNA segmented virus has high genetic variability and may have rearrangements between the genes of different viruses. In 2006, 521 samples of children younger than 5 years were analyzed and 25 tested positive for Influenza A virus, of which the subtype H3N2 is the most prevalent (68%). Five genes of 18 samples were sequenced and 13 sequences of HA, 12 of NP, 14 of M and 10 of NS obtained were. The presence of this several mutations, especially in the HA and NA genes probably helped the replacement of the vaccine strain in that year. All H3N2 subtype samples showed points of resistance to M2 inhibitors. The phylogenetic analysis revealed the circulation of different lineages in the same year, for both H1 and H3, and the presence of two rearrangements involving the HA and NP genes. These results indicate the influence of rearrangements in the evolution of the virus and emphasize the need for monitoring of circulation and characterization of genes.