This bar plot shows the number of illnesses from disease outbreaks by month, with bars colored by the primary transmission mode (food or water). A dropdown menu filters the visualization to display only the selected mode. The chart uses Vega-Lite API and Vega tooltip, with data loaded via d3.csv from a Gist-hosted National Outbreak Public Data Tool. The x-axis sorts months in descending order, while the y-axis aggregates the sum of illnesses.