[Doubling of the number of cases of tick bites and lyme borreliosis seen by general practitioners in the Netherlands].

This research focused on discovering the current distribution and incidence of tick bites and Lyme borreliosis (Lyme disease) in the Netherlands. The study found that cases observed by general practitioners doubled between 1994 and 2001, likely due to changes in ecological factors and human behavior.

Methodology

• The researchers conducted a retrospective questionnaire study using all Dutch general practice clinics as the sampling pool.
• In April 2002, all Dutch general practitioners were asked to complete a questionnaire. It revealed the number of tick bite cases and instances of erythema migrans (a rash often seen in early stages of Lyme disease) they attended to in 2001, as well as their practice size.
• The team then endeavored to find associations with potential risk factors at the municipal level.
• The findings were compared to those of an identical study carried out in 1995.

Results

• A response rate of 64.5% was achieved, with 4730 out of a possible 7330 practitioners participating.
• Collectively, doctors reported seeing around 61,000 patients in 2001 suffering from tick bites and further 12,000 exhibiting erythema migrans.
• The research team estimated the incidence of erythema migrans to be 73 per 100,000 inhabitants.
• Certain areas with higher associated risk factors were identified. These regions were commonly characterized by a large forested area, sandy soil, high population of roe deer, and significant tourist activities.
• Negative associations were found between the incidence of tick bites/erythema migrans and the level of urbanization.
• The study also found a correlation between the upsurge in tick bites and erythema migrans since 1994 with certain factors. Increases in tourist activity, urban forestry projects, and horse populations correlated with a rise in reported cases.

Conclusions

• The study has determined a doubling in the instances of tick bites and erythema migrans seen by general practitioners between 1994 and 2001.
• The increase can be attributed, at least in part, to changes in ecological risk factors and human behavior.
• The researchers suggest that the number of Lyme disease cases can be reduced through preventative information about ticks and their removal. They also propose additional education for patients on recognizing erythema migrans.