A method for active surveillance of selected communicable diseases.

In 1991, an initiative was launched in the Western Pacific Region of WHO to eradicate poliomyelitis by the year 2000. Confirmation of eradication requires a certification process, in which specific criteria must be met. A hospital-based surveillance system was developed. It was sensitive enough to detect, at least one case of acute flaccid paralysis (AFP) per 100,000 children under age 15 per year, which is considered the "background rate" of AFP. This system was instituted in 1997 in most countries in the Pacific, and included measles and neonatal tetanus as well as AFP. By mid-1998, 53 hospitals in the Pacific were submitting monthly forms indicating whether or not AFP, suspect measles, or neonatal tetanus had been seen in the preceding month. Compliance was excellent, with over 80% of forms submitted to WHO in 1998, thus meeting the certification standard. In 1999 a proposal was made to expand this method, in selected countries, to encompass most conditions presenting with acute fever plus rash, thus including, for example, cases of rubella and dengue. Important aspects of such surveillance include the capacity to confirm diagnoses in the laboratory, and to take effective public health action. A coordinated laboratory network had been established previously for virological analysis of stool specimens for conditions causing AFP, but laboratory support for other conditions is currently the responsibility of individual hospitals to arrange.