An enhanced surveillance system for AFI was established at the Saint Luke's Episcopal Hospital, in Ponce, Puerto Rico. Located ∼45 miles southwest of San Juan, Ponce is one of the 78 administrative municipalities of Puerto Rico and the second largest city (Figure 1). This hospital is a tertiary, acute-care facility that provides healthcare to patients from over 20 municipalities, has more than 54,000 patient visits to its ED annually,15 and is the main teaching affiliate of the Ponce School of Medicine.