BACKGROUND: Monitoring the emergence of drug-resistant influenza variants is crucial in influenza surveillance programs. OBJECTIVES: Influenza A kinetics and the emergence of drug-resistant strains in hospitalized patients treated with oseltamivir were investigated. STUDY DESIGN: Sequential samples from oseltamivir-treated and -untreated hospitalized patients in the period November 2011 through April 2012 were analyzed. NA gene was sequenced in samples from oseltamivir treated patients. Clonal analysis of the viral population was performed in patients unresponsive to treatment. Viral kinetics was determined in 24 (14 immunocompromised and 10 immunocompetent) A(H3N2)-positive patients treated and 24 (10 immunocompromised and 14 immunocompetent) untreated patients. RESULTS: Viral shedding was significantly reduced in treated vs untreated immunocompromised patients (7 vs 22 days, p<0.05, respectively). Viral load decreased significantly in immunocompromised and immunocompetent treated patients as compared with immunocompromised and immunocompetent untreated patients (0.73 and 0.93 vs 0.47 and 0.45 log10/day, p<0.05). In two (8.3%) treated patients with prolonged virus shedding, the oseltamivir resistance R292K mutation was revealed. In these patients, clonal analysis of the virus population showed the presence of additional oseltamivir-resistant mutants (E119V, N294S and deletion Del247-250). CONCLUSIONS: Oseltamivir resistance is reported for the first time in A(H3N2) virus strains during the 2011-2012 influenza season. Different drug-resistant viruses emerged in hospitalized immunocompromised patients showing prolonged virus shedding.
BACKGROUND: Monitoring the emergence of drug-resistant influenza variants is crucial in influenza surveillance programs. OBJECTIVES: Influenza A kinetics and the emergence of drug-resistant strains in hospitalized patients treated with oseltamivir were investigated. STUDY DESIGN: Sequential samples from oseltamivir-treated and -untreated hospitalized patients in the period November 2011 through April 2012 were analyzed. NA gene was sequenced in samples from oseltamivir treated patients. Clonal analysis of the viral population was performed in patients unresponsive to treatment. Viral kinetics was determined in 24 (14 immunocompromised and 10 immunocompetent) A(H3N2)-positive patients treated and 24 (10 immunocompromised and 14 immunocompetent) untreated patients. RESULTS: Viral shedding was significantly reduced in treated vs untreated immunocompromised patients (7 vs 22 days, p<0.05, respectively). Viral load decreased significantly in immunocompromised and immunocompetent treated patients as compared with immunocompromised and immunocompetent untreated patients (0.73 and 0.93 vs 0.47 and 0.45 log10/day, p<0.05). In two (8.3%) treated patients with prolonged virus shedding, the oseltamivir resistance R292K mutation was revealed. In these patients, clonal analysis of the virus population showed the presence of additional oseltamivir-resistant mutants (E119V, N294S and deletion Del247-250). CONCLUSIONS:Oseltamivir resistance is reported for the first time in A(H3N2) virus strains during the 2011-2012 influenza season. Different drug-resistant viruses emerged in hospitalized immunocompromised patients showing prolonged virus shedding.
Authors: Henju Marjuki; Vasiliy P Mishin; Anton P Chesnokov; Joyce Jones; Juan A De La Cruz; Katrina Sleeman; Daisuke Tamura; Ha T Nguyen; Ho-Sheng Wu; Feng-Yee Chang; Ming-Tsan Liu; Alicia M Fry; Nancy J Cox; Julie M Villanueva; Charles T Davis; Larisa V Gubareva Journal: J Infect Dis Date: 2014-08-14 Impact factor: 5.226
Authors: Alireza Eshaghi; Sarah Shalhoub; Paul Rosenfeld; Aimin Li; Rachel R Higgins; Peter J Stogios; Alexei Savchenko; Nathalie Bastien; Yan Li; Coleman Rotstein; Jonathan B Gubbay Journal: Antimicrob Agents Chemother Date: 2014-09-22 Impact factor: 5.191
Authors: Rubaiyea Farrukee; Celeste Ming-Kay Tai; Ding Yuan Oh; Danielle E Anderson; Vithiagaran Gunalan; Martin Hibberd; Gary Yuk-Fai Lau; Ian G Barr; Veronika von Messling; Sebastian Maurer-Stroh; Aeron C Hurt Journal: PLoS Pathog Date: 2020-06-18 Impact factor: 6.823