[Tick-borne diseases and changes in the ecosystem in Lorraine].

The number of persons suffering from tick-borne diseases has notably increased in the French region of Lorraine since the mid 1990s. Greater awareness of the pathology is insufficient to explain such an increase in incidence. Instead, the proliferation of ticks is a major factor in the increased incidence of cases, and is mainly due to a modification of the ecosystem. Prophylaxis is based upon appropriate information for persons concerned and requires a sound understanding of the biology and habits of the vector ticks. Numerous factors--anthropogenic, natural, social--may contribute to the destabilisation of a well-balanced ecosystem, but all are more or less the direct result of human activity. The geographic specificities of this region may be an additional factor in the emergence of tick-borne diseases.