Table 2 Proposed alert signals (triggers for early response) as suggested by the WHO-TDR expert meeting (June 2012)
Trigger | Evidence or expert opinion** | Feasibility | Further research needed*** |
|---|---|---|---|
New predominant serotype introduced | +++ | Most countries | +++ |
Changes in age group distribution | ++ | Most countries | +++ |
Increased number of hospitalised/outpatient fever cases/probable dengue* | +++ | Most countries | +++ |
Increase in vector presence | ++ | Most countries | +++ |
Increase in news reporting dengue outbreaks, social network comments | + | Few countries | ++++ |
Climate changes: increase in rainfall/temperature/humidity | ++ | Most countries | +++ |
Increase in % positive serology* | ++++ | Most countries | + |
Increase internal displacement/population mobility | + | Context dependent | ++++ |
Cluster identified through GIS mapping | ++ | Few countries | ++ |
Identification of outbreak in a neighboring geographical unit (state, district, province, country)* | ++++ | Most countries | ++ |