Does Oseltamivir Work against Influenza B?

The article by Sugaya et al. [1] in the current issue of Clinical Infectious Diseases, “Lower Clinical Effectiveness of Oseltamivir against Influenza B Contrasted with Influenza A Infections in Children,” is of interest for several reasons. The primary message is that, in young children, oseltamivir it not nearly as effective against influenza B as it is against influenza A. Although it reports on an observational trial with retrospective controls, the validity of the careful clinical observations are supported by sustained shedding of influenza B in spite of oseltamivir therapy and by laboratory data documenting the high concentrations of oseltamivir necessary to inhibit the circulating influenza B strains. It is remarkable that such precise data on duration of fever can be accumulated in a clinical setting. For this, we can only compliment the investigators and the Japanese parents and their children who kept such careful clinical records. The authors are to be commended for the quality of their clinical observations and their use of laboratory documentation to bolster their findings. A second point of interest is the observation that there are remarkable differences in the approach to the treatment and prevention of influenza in children between Japan and the United States. It is clear that, in Japan, antivirals play a major role in the treatment of influenza and that, in support of their use, there is a major effort made to diagnose influenza using rapid antigen techniques. The Japanese approach is, at least in part, designed to limit the overall impact of influenza. They have previously demonstrated that childhood vaccination limits spread of illness to the adult population [2]. The broad scope of influenza in children and the limited clinical suspicion of pediatric influenza in the United States was recently pointed out by Poehling et al. [3]. Finally, these international differences in the approach to clinical care encourage us to devote time to understanding such disparities in healthcare delivery and, through that exercise, to define optimal care. Such disparities have been examined quite extensively in the United States, particularly in the realms of surgical procedures and therapeutic medicine [4]. However, disparities in medical practices between nations have not undergone the same scrutiny. We look forward to further studies from this group defining the importance of pediatric influenza and instructing all of us in the optimal management of this disease. Acknowledgments