Map Database
Per-state records that drive the map layer on the homepage. Each entry carries a risk tier, a primary reservoir species, and a historical case-context number — never as a real-time count, always as a longitudinal signal.
Key facts
Every state in the map dataset carries the same shape, so the legend stays meaningful as you scan.
The tiers are signal categories for scanning the map, not clinical risk scores.
Reservoir species shape which hantavirus is most relevant in a given region. Deer mouse country dominates the western U.S. signal map; cotton rat and rice rat country picks up across the Southeast; the white-footed mouse extends across much of the eastern and central U.S.
A state being marked elevated does not mean ongoing transmission, and a baseline state is not a safe-zone label. Hantavirus exposure is local — it tracks specific structures, specific rodent populations, and specific cleanup behavior, not state borders.
The natural next step is ingesting state health-department feeds where they exist, alongside CDC's NNDSS weekly tables, so the state layer can carry a date-stamped 'last updated' value per record rather than a single editorial snapshot.
Related on HantaScan
Primary Sources