Browsing by Author "Andrade, Helena Rebelo de"
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- Antiviral drug profile of seasonal influenza viruses circulating in Portugal from 2004/2005 to 2008/2009 winter seasonsPublication . Correia, Vanessa; Andrade, Helena Rebelo de; Santos, Luís A.; Lackenby, Angie; Zambon, MariaA research project on antiviral drug resistance of influenza viruses circulating in Portugal has been carried out since 2007. Here, the first results obtained regarding the evaluation of susceptibility to amantadine and oseltamivir are presented. Information about antiviral prescription and exposure was available through the National Influenza Surveillance Programme. Amantadine susceptibility was evaluated by pyrosequencing for known resistance markers on 178 influenza A strains from 2004/2005 to 2006/2007. Susceptibility to oseltamivir was evaluated by 50% inhibitory concentration determination on 340 virus strains from 2004/2005 to 2008/2009, 134 of which were further analyzed by sequencing of the neuraminidase gene. This study revealed that influenza antiviral drugs were rarely prescribed at national level. Resistance to amantadine was observed on only A(H3N2) strain isolated during 2005/2006 and on 38 (74.5%) of the 51 A(H3N2) strains from 2006/2007, all carrying the mutation S31N in their M2 sequence. Oseltamivir resistance was observed in 6 (20.7%) of the 29 A(H1N1) strains from 2007/2008 and in all strains from 2008/2009, which exhibited extremely high IC(50) values and carrying the mutation H275Y in their neuraminidase sequence. The national data generated and analyzed in this study may contribute to increase the knowledge on influenza antiviral drug resistance which is a problem of global concern.
- Outbreak of acute respiratory infection among infants in Lisbon, Portugal, caused by human adenovirus serotype 3 and a new 7/3 recombinant strainPublication . Andrade, Helena Rebelo de; Pereira, Cristiana; Gíria, Marta; Prudêncio, Ema; Brito, Maria João; Calé, Etelvina; Taveira, NunoHuman adenoviruses (AdVs) typically cause mild illnesses in otherwise healthy hosts. We investigated a pediatric outbreak of acute respiratory infection with fatal outcomes that occurred in Lisbon, Portugal, in 2004. Biological specimens were collected from 83 children attending two nurseries, a kinesiotherapy clinic, and the household of a nanny. Adenovirus infection was confirmed in 48 children by PCR and virus isolation. Most (96%) isolates were classified as being of subspecies B1. Phylogenetic analysis of fiber and hexon gene sequences revealed that most infants were infected with AdV serotype 3 (AdV3) strains. Infants attending one nursery harbored a new recombinant strain containing an AdV serotype 7 hexon and serotype 3 fiber (AdV7/3). Both the AdV3 and the AdV7/3 strains caused fatal infections. Two different serotype 3 strains were circulating in Lisbon in 2004, and the new AdV7/3 recombinant type originated from only one of those strains. These results demonstrate that recombination leads to the emergence of new adenovirus strains with epidemic and lethal potential.
- Perfil de suscetibilidade do vírus influenza aos antivirais específicos para a gripe de 2004 a 2011Publication . Correia, Vanessa; Santos, Luis André; Andrade, Helena Rebelo de
- Variantes genéticas do gene IFITM3 revelam um potencial modificador da gravidade sintomática da gripePublication . David, Susana; Correia, Vanessa; Antunes, Liliana; Faria, Ricardo; Ferrão, José; Faustino, Paula; Nunes, Baltazar; Maltez, Fernando; Lavinha, João; Andrade, Helena Rebelo deAs epidemias de gripe representam um sério problema de saúde pública com elevados custos económicos. Foi sugerido que um dos alelos do gene IFITM3 (rs12252-C) constitui um impor tante fator de risco de base populacional para as formas graves da gripe por infeção pelo vírus A(H1N1)pdm09. Analisámos variantes do IFITM3 associadas à gravidade da doença em doentes por tugueses (n=41). Foram identificados sete SNPs no amplicão de 352bp do IFITM3 em torno do rs12252. De acordo com HapMap, o SNP rs34481144 per tence ao mesmo bloco de desequilíbrio de ligação (LD) que rs12252, e está em LD com rs6421983. A associação negativa com formas sintomáticas graves em relação a ligeiras obser vada para o alelo rs34481144-A é sugestiva de um efeito protetor no modelo de hereditariedade dominante. Para além disso, o haplótipo Hap4 com rs34481144-A, e sem o rs12252-C, mostrou estar significativamente associado a gripe sintomaticamente ligeira. Por outro lado, apesar de a um nível de significância limiar, o haplótipo Hap1 com rs34481144-G, sem rs12252-C, mostrou-se associado à gripe com sintomatologia grave. Em comparação com a população por tuguesa em geral, foram obser vadas diferenças significativas nas frequências do alelo possivelmente protetor rs34481144-A no grupo com sintomatologia grave, do Hap1 deletério no grupo com sintomatologia ligeira e do Hap4 protetor no grupo com doença grave. A proporção de casos com sintomas graves que poderiam ser evitados se todos os indivíduos da população apresentassem o alelo protetor rs34481144-A foi estimada em 56% e 64%, respetivamente na população em geral e no grupo de indivíduos com doença ligeira. A implicação destas variantes nos fenótipos da doença necessita de estudos de validação, nomeadamente de natureza funcional.