Duration of fever and other symptoms after the inhalation of laninamivir octanoate hydrate: A study of the 2017/18 and 2018/19 seasons and comparison with the 2011/12 to 2016/17 Japanese influenza seasons.

Introduction: Large scale investigation of the clinical effectiveness of neuraminidase inhibitors for circulating influenza viruses are important along with the surveillance of virus susceptibility in vitro.

Methods: The duration of fever and other influenza symptoms as markers of the clinical effectiveness of laninamivir octanoate hydrate (laninamivir) were investigated in the Japanese 2017/18 and 2018/19 influenza seasons and compared with the results of the previous six seasons.

Results: Influenza A(H1N1)pdm09, A(H3N2), and B were found in 14, 45, and 52 patients in the 2017/18 season and in 22, 62, and 0 in the 2018/19 season, respectively.

Susceptibility of epidemic viruses to neuraminidase inhibitors and treatment-emergent resistance in the Japanese 2019-20 influenza season.

Objectives: To investigate the susceptibility of epidemic influenza viruses to neuraminidase inhibitors (NAIs) and the emergence of resistant viruses after treatment, a prospective, observational study was done in the 2019-20 Japanese influenza season.

Methods: Influenza viruses were isolated before and twice after treatment, the first at day 5 and the second at day 10. The 50% inhibitory concentrations (ICs) to oseltamivir, zanamivir, peramivir, and laninamivir were measured and compared with those of 2010-11 to 2018-19 seasons.

In vitro neuraminidase inhibitory concentration (IC) of four neuraminidase inhibitors in the Japanese 2018-19 season: Comparison with the 2010-11 to 2017-18 seasons.

To assess the extent of susceptibility to the four most commonly used neuraminidase inhibitors (NAIs) of the epidemic viruses in the 2018-19 Japanese influenza season, we measured the 50% inhibitory concentration (IC) of four NAIs, oseltamivir, zanamivir, peramivir, and laninamivir, for influenza virus isolates from patients and compared them with the results from the 2010-11 to 2017-18 seasons. Viral isolation was done with specimens obtained prior to and after treatment, and the type/subtype was determined by RT-PCR using type- and subtype-specific primers. The IC was determined by a neuraminidase inhibition assay using a fluorescent substrate.

Duration of fever and PA/I38X-substituted virus emergence in patients treated with baloxavir in the 2018-2019 influenza season.

Duration of fever and virus persistence after baloxavir administration were investigated in 81 outpatients, 16 with A(H1N1)pdm09 and 65 with A(H3N2) in the Japanese 2018-2019 influenza season. Only eight cases of A(H3N2) viruses were detected post-dose. PA/I38T-substituted viruses were detected in four (6.

In vitro neuraminidase inhibitory concentration (IC) of four neuraminidase inhibitors in the Japanese 2017-18 season: Comparison with the 2010-11 to 2016-17 seasons.

To assess the extent of susceptibility to the four most commonly used neuraminidase inhibitors (NAIs) of the viruses epidemic in the 2017-18 Japanese influenza season, we measured the 50% inhibitory concentration (IC) for influenza virus isolates from patients and compared them with the results from the 2010-11 to 2016-17 seasons. Viral isolation was done with specimens obtained prior to treatment, and the type and subtype was determined by RT-PCR using type- and subtype-specific primers. The IC was determined by a neuraminidase inhibition assay using a fluorescent substrate.

Duration of fever and other symptoms after the inhalation of laninamivir octanoate hydrate in the 2016/17 Japanese influenza season; comparison with the 2011/12 to 2015/16 seasons.

The duration of fever and symptoms after laninamivir octanoate hydrate (laninamivir) inhalation were investigated in the Japanese 2016/17 influenza season and the results were compared with those of the 2011/12 to 2015/16 seasons. A total of 1278 patients were evaluated for the duration of fever and symptoms in the six studied seasons. In the 2016/17 season, the influenza types/subtypes of the patients were 6 A (H1N1)pdm09 (2.

In vitro neuraminidase inhibitory concentration (IC) of four neuraminidase inhibitors in the Japanese 2016-17 season: Comparison with the 2010-11 to 2015-16 seasons.

To assess the extent of susceptibility to the four most commonly used neuraminidase inhibitors (NAIs) in the viruses epidemic in the 2016-17 Japanese influenza season, we measured the 50% inhibitory concentration (IC) of these NAIs for influenza virus isolates from patients and compared them with the results from the 2010-11 to 2015-16 seasons. Viral isolation was done with specimens obtained prior to treatment, and the type and subtype was determined by RT-PCR using type- and subtype-specific primers. The IC was determined by a neuraminidase inhibition assay using a fluorescent substrate.

Duration of fever and other symptoms after the inhalation of laninamivir octanoate hydrate; comparison of the 2011/12 to 2015/16 Japanese influenza seasons.

The duration of fever and symptoms after laninamivir octanoate hydrate (laninamivir) inhalation were investigated in the Japanese 2015/16 influenza season, and the results were compared with those of the 2011/12 to 2014/15 seasons. A total of 1068 patients were evaluated for the duration of fever and symptoms in the five studied seasons. The influenza types/subtypes were 125 A(H1N1)pdm09 (62.

In vitro neuraminidase inhibitory concentration (IC) of four neuraminidase inhibitors in the Japanese 2015-16 season: Comparison with the 2010-11 to 2014-15 seasons.

To assess the extent of susceptibility to the four most commonly used neuraminidase inhibitors (NAIs) in the viruses epidemic in the 2015-2016 influenza season in Japan, we measured the 50% inhibitory concentration (IC) of NAIs for influenza virus isolates and compared them with the results from the 2010-11 to 2014-15 influenza seasons. Viral isolation was done with specimens obtained prior to treatment, and the type and subtype of influenza was determined by RT-PCR using type- and subtype-specific primers. The IC50 was determined by a neuraminidase inhibition assay using a fluorescent substrate.

Duration of fever and other symptoms after the inhalation of laninamivir octanoate hydrate for influenza treatment; comparison among the four Japanese influenza seasons from 2011-2012 to 2014-2015.

The duration of fever and other symptoms as markers of the clinical effectiveness of laninamivir octanoate hydrate (laninamivir) were investigated in the Japanese 2014-2015 influenza season and the results were compared with those of the previous three seasons, 2011-2012 to 2013-2014. From these four seasons, the data of 636 influenza A(H3N2) and 128 influenza B patients was available for analysis. No significant difference was found in their baseline characteristics.

In vitro neuraminidase inhibitory concentration (IC50) of four neuraminidase inhibitors against clinical isolates of the influenza viruses circulating in the 2010-2011 to 2014-2015 Japanese influenza seasons.

To assess the extent of viral resistance to the four neuraminidase inhibitors (NAIs), we measured their 50% inhibitory concentration (IC50) for influenza virus isolates from the 2014-2015 influenza season for comparison with those circulating in the 2010-2011 to 2013-2014 influenza seasons. Viral isolation was done with specimens obtained prior to treatment, and the type and subtype of influenza was determined by RT-PCR using type- and subtype-specific primers. The IC50 was determined by a neuraminidase inhibition assay using a fluorescent substrate.

Clinical outcome of laninamivir octanoate hydrate for influenza in the 2013-2014 Japanese season.

The clinical outcome of laninamivir octanoate hydrate (laninamivir) in the Japanese 2013-2014 influenza season was investigated. A total of 235 patients were enrolled, of whom 222 were evaluated for the duration of fever and other symptoms. The types/subtypes were 101 A(H1N1)pdm09 (45.

In vitro neuraminidase inhibitory activity of four neuraminidase inhibitors against clinical isolates of the influenza virus circulating in the Japanese 2013-2014 season.

To assess the extent of viral resistance, we measured the 50% inhibitory concentration (IC50) of neuraminidase inhibitors (NAIs) for the influenza virus isolates in the 2013-2014 influenza season and compared the results to those of the 2010-2011 to 2012-2013 influenza seasons. Viral isolation was done with specimens obtained prior to treatment, and the type and subtype of influenza was determined by RT-PCR using type- and subtype-specific primers. The IC50 was determined by a neuraminidase inhibition assay using a fluorescent substrate.

Continued effectiveness of laninamivir octanate hydrate for influenza treatment in Japan: comparison between the 2011-2012 and 2012-2013 influenza seasons.

The clinical effectiveness of Laninamivir octanoate hydrate (laninamivir) was investigated in the Japanese 2012-2013 influenza season for comparison with that of the Japanese 2011-2012 influenza season. A total of 235 patients were enrolled, of whom 210 were evaluated for the duration of fever and other symptoms. The median durations of fever for A(H3N2) were 32.

In vitro neuraminidase inhibitory activity of four neuraminidase inhibitors against clinical isolates of influenza virus in the Japanese 2012-2013 season.

The neuraminidase inhibitors (NAIs) oseltamivir phosphate (Tamiflu(®)), zanamivir (Relenza(®)), laninamivir octanoate (Inavir(®)), and peramivir (Rapiacta(®)) have been available for the treatment of influenza in Japan since 2010. The emergence of resistant virus to any of the NAIs is a great concern for influenza treatment. To assess the extent of viral resistance, we measured the 50% inhibitory concentration (IC50) of each NAI for influenza virus isolates in the 2012-2013 influenza season and compared the results to those of the 2010-2011 and 2011-2012 influenza seasons.

In vitro neuraminidase inhibitory activity of four neuraminidase inhibitors against influenza virus isolates in the 2011-2012 season in Japan.

The neuraminidase inhibitors oseltamivir phosphate (Tamiflu®), zanamivir (Relenza®), laninamivir octanoate (Inavir®), and peramivir (Rapiacta®) have been available for the treatment of influenza in Japan since 2010. To assess the extent of viral resistance, we measured the 50% inhibitory concentration (IC₅₀) of each drug for influenza virus isolates from the 2011-2012 influenza season. Specimens were obtained from patients prior to treatment.

The duration of fever and other symptoms after the initiation of laninamivir octanoate hydrate in the Japanese 2011-2012 influenza season.

Laninamivir octanoate hydrate (laninamivir) is a long-acting, single inhalation neuraminidase inhibitor that was approved in Japan in 2010 for the treatment of influenza A and B virus infection. We investigated the duration of fever and other symptoms after the initiation of laninamivir in the Japanese 2011-2012 influenza season. Virus isolation was done and the 50% inhibitory concentration (IC₅₀) was measured for the virus isolates at days 1 and 5.

Persistence of pandemic influenza H1N1 virus in young patients after oseltamivir therapy in the 2009-2010 season: a comparison with seasonal H1N1 with or without H275Y mutation.

Comparison of the viral persistence of pandemic H1N1 (H1N1pdm) and seasonal H1N1 with or without H275Y mutation after oseltamivir therapy has not been adequately done. Virus was isolated before and on days 4-6 from the start of oseltamivir treatment for 158 cases of seasonal (2007-2008 and 2008-2009 seasons) or pandemic (2009-2010 season) H1N1 influenza. Sequence analysis was done for each season and NA inhibition assay (IC(50)) was done in the 2009-2010 season.

The post-infection outcomes of influenza and acute respiratory infection in patients above 50 years of age in Japan: an observational study.

Objectives: Influenza can be a serious illness, especially for older people, and reducing the impact of influenza in elderly is important. The objective of this study was to estimate the prevalence and postinfection outcomes of influenza among the over-50 population in Japan.

Design: An observational study was designed to ascertain the proportion of influenza cases in a population aged ≥ 50 years with acute respiratory infection (ARI) and to determine the postinfection outcomes of their illness during the 2008-09 influenza season in Japan.

Clinical effectiveness of oseltamivir and zanamivir for treatment of influenza A virus subtype H1N1 with the H274Y mutation: a Japanese, multicenter study of the 2007-2008 and 2008-2009 influenza seasons.

Background: Influenza A virus subtype H1N1 with the H274Y mutation emerged and spread worldwide. However, the clinical effectiveness of the neuraminidase inhibitors, oseltamivir and zanamivir, has not been adequately reevaluated.

Methods: Data from 164 patients with H1N1 virus infection and 59 patients with H3N2 virus infection during the 2008-2009 influenza season and 68 patients with H1N1 virus infection during the 2007-2008 influenza season who received a neuraminidase inhibitor were analyzed.

Clinical effectiveness of oseltamivir for influenza A(H1N1) virus with H274Y neuraminidase mutation.

Objective: To evaluate the clinical effectiveness of oseltamivir therapy started within 48h of the onset for influenza A(H1N1) virus with H274Y neuraminidase (NA) mutation.

Methods: Virus was isolated before and four to six days after starting oseltamivir treatment from 73 outpatients with influenza A(H1N1) virus in the 2007-2008 and 2008-2009 seasons. NA inhibition assays (IC(50)) and sequence analyses were done using influenza viruses isolated from these patients.