The effect of timing of oseltamivir chemoprophylaxis in controlling influenza B outbreaks in long-term care facilities in Manitoba, Canada, 2017-2018: A retrospective cohort study

Abstract

A retrospective cohort study (n=8) was used to examine the effect of the timing of administration of oseltamivir chemoprophylaxis for the control of influenza B outbreaks among residents in long-term care facilities in Manitoba, Canada during the 2017-2018 influenza season. Delay of oseltamivir chemoprophylaxis was associated with increased odds of influenza-like illness in both univariate and multivariable analyses with an adjusted odds ratio of 1.34 (95% CI: 1.12-1.60) per day for influenza B.