Methodology

Every record on this site is tagged with a tier. Tiers determine how a report is treated and whether a case is plotted.

• T1Health authorities. who.int, cdc.gov, ecdc.europa.eu, paho.org, argentina.gob.ar, minsal.cl, rivm.nl, gov.uk, dshs.texas.gov, bag.admin.ch, rki.de, moh.gov.sg. A single Tier-1 report is sufficient to plot a case.
• T2Expert surveillance. promedmail.org, cidrap.umn.edu. Become news items, never standalone cases.
• T3Press. reuters.com, apnews.com, bbc.com, nytimes.com, statnews.com, nature.com, science.org, ft.com, theguardian.com, npr.org. Two independent Tier-3 reports within 72 hours are required to plot a case. Verification method is recorded on the case row as tier1, t3-corroborated, or t3-catchup for one-shot historical fills.

Anything outside the source tiers is dropped at ingestion. Wikipedia, blogs, Substack, social posts, and aggregator sites cannot become a case — even if a model surfaces them as a citation. The cases pipeline maintains a strict ~15-domain allowlist; a separate, broader allowlist is used for the news feed only.

Latitude and longitude come only from the source itself or from Nominatim. We never invent coordinates. Cases that yield no coordinates are kept in the database for transparency but excluded from the globe; they appear in the news feed with country only.

Ingestion runs every four hours via Vercel cron with a hard ceiling of 100K Grok tokens per tick. Endemic background pulls run once daily at 06:00 UTC. The page revalidates every five minutes; the closest-case banner polls the Edge endpoint once a minute. The footer shows the timestamp of the last successful run.

Arcs reflect documented MV Hondius disembarkation events, not the live ship position: Saint Helena (Apr 24, 2026 — 30 passengers disembarked, some onward by air via Johannesburg), Cape Verde (early May 2026 — medical evacuations to European hospitals), and Tenerife (May 9, 2026 onward — post-docking). Cases reported before any disembarkation, or originating before the voyage (e.g. presumed pre-boarding exposure in Argentina), are shown as markers without an arc.

The closest-confirmed-case banner uses the rough latitude/longitude that Vercel attaches to the request at the network edge. We compute the distance, return it, and forget. We never persist your IP, your coordinates, your city, or your country anywhere — not in logs, not in Supabase, not in analytics. Umami, when enabled, only receives a coarse distance bucket (<100, 100-500, 500-2000, >2000).

Data is available under CC-BY-4.0; cite hantavirus.wtf and preserve source links. Found a wrong number, missing source, or incorrect attribution? Email contact@hantavirus.wtf. We treat correction speed as a first-class metric.