[Community transmission of pandemic influenza (H1N1) 2009 from School Outbreaks in the Madrid region, Spain: May-June 2009].

Background: The first pandemic influenza (H1N1) 2009 confirmed case acquired in the Madrid Region was diagnosed in May 20th. This was the index case of the first outbreak in a school in the Madrid Region (MR). The aim of this paper is to describe school outbreaks that took place during the spring in 2009, the control measures implemented and the beginning of the community transmission of this virus in the Region.