A horizontal bar chart shows the number of hospitalized confirmed COVID-19 patients for the top 20 counties, fetched from a CSV file via `d3.csv`. The chart uses React state and effects to load data, then renders SVG `rect` elements scaled with `d3.scaleBand` for counties and `d3.scaleLinear` for patient counts. Orange gridlines and tick labels are drawn manually, with axes positioned using SVG transforms.