FIG. 4.
Ankle swelling in different mouse strains infected with B. burgdorferi. The indicated mouse strains were infected by intradermal injection of 2,000 B. burgdorferi organisms, and ankles were measured weekly as described in Materials and Methods. Data points represent the averages and standard deviations of values for eight infected animals, and results are representative of two separate experiments. Mock-infected animals showed no increase in ankle swelling at any time point (data not shown).