Outbreaks of influenza a among nonvaccinated healthcare workers: Implications for resource-limited settings

We identified 3 outbreaks of influenza A (attack rates, 18%-24%) among Thai healthcare workers in intensive care units. All outbreaks were epidemiologically linked to an index patient with pneumonia due to influenza A virus (subtype H3N2). The investigations of these outbreaks incurred costs that exceeded the estimated costs of healthcare worker influenza vaccination by more than 10-fold.