Surveillance is the collection, collation, analysis and interpretation of data for public health action. Sentinel surveillance is surveillance based at designated institutions or sites, which have been selected for their geographic location, medical specialty, or ability to accurately diagnose and report high-quality data. Hospital-based Surveillance of bacterial pneumonia and meningitis began in the Americas in 2007. In 2009, the following nine countries reported data to PAHO: Bolivia, Brazil, Ecuador, El Salvador, Guatemala, Honduras, Panama, Paraguay and Venezuela. Argentina, Nicaragua and Peru are in the process of implementing hospital-based surveillance.