Figure 1.

Decision tool for determining key criteria in developing a protocol for the selection of sentinel unit locations for vector-borne diseases. ^aSite should have been used for a similar objective. ^bThe variation in the environment is judged significant by the investigators. ^cEarly warning system. ^dIt is also relevant to consider potential important population influx e.g., from tourism, occupational reasons. ^eHuman activities which influence exposure to vectors/vector-borne diseases.