Climate change, tick-borne encephalitis and vaccination needs in Sweden - a prediction model

A future, global, climate change may indirectly lead to changes in the transmission and incidence of several vector-borne diseases. This paper presents an example of a modeling tool for projections of possible changes in the incidence of tick-borne encephalitis (TBE), and the subsequent changes in vaccination needs, during the next half-century in Sweden. The model is based on the Hadley Center's regional temperature predictions for the year 2050, taking into account the IPCC IS92 'non-intervention scenario'. The model has been constructed into STELLA, a graphical dynamic-simulation, soft-ware program. The model project an increase in TEE incidence in Stockholm County, a high-endemic region in Sweden, during the next 50 years. According to this simplified model, the annual vaccination rate need to increase by 3-4-fold during the next half century in order to prevent the projected increases in TEE incidence in the region from a climatic change. (C) 1998 Elsevier Science B.V. All rights reserved.