Characteristics of national surveillance systems.

*Case definition used for dengue surveillance was same as World Health Organization Region Office recommended definition: WPRO = Western Pacific Regional Office; SEARO = Southeast Asia Regional Office; Pan American Health Organization;†Method of case ascertainment by national dengue surveillance system: active, passive or sentinel site surveillance;‡Source or location where cases are detected: OP = Outpatient clinics; IP = Inpatient or hospitalized;§Reporting of dengue cases is mandated by law;¶Mosquito surveillance is included as part of the national surveillance system and is not just in response to outbreaks.