(A) P. berghei sporozoite trajectories obtained with manual (left) and automated (right) tracking methods. (B) Image processing and automated tracking method. Shown are images illustrating each step of automated tracking: The raw data image shows the first frame of time-lapse microscopy of P. berghei sporozoites (red) after intradermal inoculation, followed by the same image after background subtraction and thresholding using Fiji software. Spot detection was run using ICY software and the final image shows the overlay with tracks generated using the spot tracking plugin of ICY software. Scale bars, 50 μm. (C) Apparent speed of sporozoites 5 to 120 min after intradermal inoculation, obtained with manual and automated tracking methods. Data is displayed in box and whisker plots with whiskers showing 10 to 90 percentiles and values below and above the whiskers shown individually. Horizontal line indicates the median speed. No statistically significant differences between the corresponding timepoints of manual and automated tracking methods were found (Kruskal-Wallis test). (D) Displacement of sporozoites 5 to 120 min after intradermal inoculation, obtained with manual and automated tracking methods. To normalize between tracks of different duration, displacement is displayed as final displacement per 30 seconds interval. Data is displayed in box and whisker plots with whiskers showing 10 to 90 percentiles and values below and above the whiskers shown individually. Horizontal line indicates the median. The only statistically significant difference in sporozoite displacement between the manual and automated tracking methods was at 120 minutes (Kruskal-Wallis test, ****p<0.0001). For panels C&D, a varying number of videos were processed for each time point: C: 5 min (3 videos/37 manual tracks/203 automated tracks), 10 min (6 videos/112 manual tracks/292 automated tracks), 20 min (4 videos/95 manual tracks/184 automated tracks), 30 min (6 videos/63 manual tracks/235 automated tracks), 60 min (7 videos/77 manual tracks/162 automated tracks), and 120 min (6 videos/44 manual tracks/151 automated tracks). D: 5 min (3 videos/61 manual tracks/203 automated tracks), 10 min (6 videos/74 manual tracks/292 automated tracks), 20 min (4 videos/47 manual tracks/184 automated tracks), 30 min (6 videos/53 manual tracks/235 automated tracks), 60 min (7 videos/65 manual tracks/162 automated tracks), and 120 min (6 videos/48 manual tracks/151 automated tracks). 