Browsing by Author "Lackenby, Angie"
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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.
- Global update on the susceptibility of human influenza viruses to neuraminidase inhibitors, 2014-2015Publication . Hurt, Aeron C.; Besselaar, Terry G.; Daniels, Rod S.; Ermetal, Burcu; Fry, Alicia; Gubareva, Larisa; Huang, Weijuan; Lackenby, Angie; Lee, Raphael T.C.; Lo, Janice; Maurer-Stroh, Sebastian; Nguyen, Ha T.; Pereyaslov, Dmitriy; Rebelo-de-Andrade, Helena; Siqueira, Marilda M.; Takashita, Emi; Tashiro, Masato; Tilmanis, Danielle; Wang, Dayan; Zhang, Wenqing; Meijer, AdamThe World Health Organization (WHO) Collaborating Centres for Reference and Research on Influenza (WHO CCs) tested 13,312 viruses collected by WHO recognized National Influenza Centres between May 2014 and May 2015 to determine 50% inhibitory concentration (IC50) data for neuraminidase inhibitors (NAIs) oseltamivir, zanamivir, peramivir and laninamivir. Ninety-four per cent of the viruses tested by the WHO CCs were from three WHO regions: Western Pacific, the Americas and Europe. Approximately 0.5% (n = 68) of viruses showed either highly reduced inhibition (HRI) or reduced inhibition (RI) (n = 56) against at least one of the four NAIs. Of the twelve viruses with HRI, six were A(H1N1)pdm09 viruses, three were A(H3N2) viruses and three were B/Yamagata-lineage viruses. The overall frequency of viruses with RI or HRI by the NAIs was lower than that observed in 2013-14 (1.9%), but similar to the 2012-13 period (0.6%). Based on the current analysis, the NAIs remain an appropriate choice for the treatment and prophylaxis of influenza virus infections.