A choropleth map visualizes the global share of the population infected with HIV/AIDS for 2017, encoding each country’s prevalence with a sequential yellow-to-red color scale. The map uses a natural Earth projection rendered as SVG via React, with `d3.geoPath` drawing country boundaries, graticules, and interiors. It loads TopoJSON world-atlas data, ISO country codes, and the HIV prevalence dataset through `d3.csv` and `d3.json`, coloring missing regions gray.