De geografische verspreiding van tekenbeten en erythema migrans in Nederland

To determine the geographic distribution of tick bites and erythema migrans in the Netherlands and to identify ecological risk factors.

Design

Retrospective study.

Setting

All general practitioners in the Netherlands.

Methods

In April 1995, all general practitioners in the Netherlands were asked to complete a postal questionnaire on the number of tick bites and erythema migrans patients seen in 1994 and the size of the practice. Reminders were sent to nonresponders. Information on ecological risk factors per municipality was obtained from a geographic information system.

Results

The response rate was 79.9. In 1994, general practitioners reported seeing approximately 33,000 patients with tick bites and 6500 with erythema migrans. The incidence of erythema migrans was estimated at 4.3 per 10,000 population. Ecological risk factors for both tick bites and erythema migrans were the sizes of the areas covered by woods and by sandy soil and the number of tourist nights per inhabitant. Tick bites were also associated with dry uncultivated land and sheep population density, and erythema migrans with cattle population density.

Conclusions

Using simple methods, a rough estimate of the incidence of erythema migrans was obtained rapidly, and high risk areas were identified. Lyme borreliosis appears to be an important problem in the Netherlands.