Seasonal characteristics of test utilization and treatment for Lyme borreliosis. Four graphs A, B, C, D in one figure. The smoothed logistic regression curve with 2 standard errors above and below the estimate shows the seasonal variation in the proportion of patients who are IgG antibody positive, IgM antibody positive or treated for Lyme disease. The horizontal line at zero indicates the mean number. Months of the year are abbreviated by the first letter.