Neuraminidase Inhibitor Treatment for Influenza B-Related Pneumonia

Early neuraminidase inhibitor (NAI) therapy may result in better outcomes in patients hospitalized with influenza B-related pneumonia, according to results of a study published in the European Journal of Microbiology & Infectious Diseases.

Influenza is a contagious respiratory viral illness that causes unavoidable hospitalizations and considerable mortality despite improvement in medical technology development and economic progress. Annually, it is estimated that 1 billion people are infected with this virus globally, with 3 to 5 million experiencing severe illness and 290 to 650 thousand related deaths. These numbers highlight that an influenza epidemic may be one of the greatest threats to global health in this century. In 1999, the United States Food and Drug Administration approved NAIs (represented by oseltamivir) as the anti-flu medication and previous clinical trials showed that early NAI treatment (within 48 hours of disease onset) can reduce the severity of the disease and the duration of symptoms by a median of 70 hours.

Influenza B is frequently overlooked as a result of seasonal influenza A outbreaks, and the pandemics that have been associated with it; however, during the 2017 to 2018 season, influenza B accounted for roughly 40% of all circulating strains of influenza in China. Therefore, this multicenter cohort study was conducted to evaluate the effect of early neuraminidase inhibitor administration on clinical outcomes in patients with laboratory-confirmed influenza B-related pneumonia.

A total of 386 immunocompetent patients with community-onset influenza B-related pneumonia from 2013 to 2019 who received care at 5 teaching hospitals in China were included in the study. All patients received NAI throughout the course of their illness and 153 patients (39.6%) received early NAI treatment, which was defined as any NAI administered within 2 days of disease onset, including oseltamivir, zanamivir, and peramivir. The effects of early NAI administration on clinical outcomes in patients with influenza B-related pneumonia were assessed using univariate and multivariate logistic regression analyses.

The results suggested that in patients with influenza B-related pneumonia, early NAI treatment was associated with decreased risk for admittance to the intensive care unit (odds ratio [OR], 0.425; P =.022), 30-day mortality (OR, 0.416; P =.036), and invasive ventilation (OR, 0.325; P =.023). In addition, multivariate logistic regression analysis suggested that an independent predictor of 30-day mortality in patients with influenza B-related pneumonia was early NAI treatment (OR, 0.306; P =.010). Results also identified several aspects of CURB-65 screening that were associated with poorer outcomes.

Overall, the study authors stated that, “In conclusion, the findings of this study indicate that early initiation of NAI therapy is associated with better outcomes in patients hospitalized with [influenza B-related pneumonia], which supports the recommendations on NAI use in the existing guidelines.”

Reference

Chen L, Han X, Li Y, Zhang C, Xing X. Impact of early neuraminidase inhibitor treatment on clinical outcomes in patients with influenza B-related pneumonia: a multicenter cohort study. Eur J Clin Microbiol Infect Dis. doi:10.1007/s10096-020-03835-6