Table 1.

Components of laboratory-based, proactive surveillance for dengue and DHFa

Type of surveillanceSamplesbApproach
Sentinel clinic and physician networkBlood from representative cases of viral syndrome, taken 3–15 days after onset of illnessRepresentative samples taken year round and processed weekly for virus isolation and for IgM antibodies
Fever alert systemBlood samples from representative cases of febrile illnessIncreased febrile illness in community investigated immediately; samples tested as above
Sentinel hospital systemc Blood and tissue samples taken during hospitalization and/or at deathAll hemorrhagic disease and all viral syndromes with fatal outcome investigated immediately and tested as above
  • a Emphasis should be placed on the interepidemic period, using a nonspecific case definition. After an epidemic begins and after the virus serotype(s) is known, the case definition should be made more specific and surveillance should be focused on severe disease.

  • b All samples are processed weekly for virus isolation and/or for dengue virus-specific IgM antibodies.

  • c Sentinel sites should be geographically representative.