About this tracker

Methodology and Data Sources

Hantavirus Tracker is an independent project. It compiles and cross-checks public information about the 2026 MV Hondius Andes virus outbreak. This page documents what we do, how we update, and how to verify any number we publish.

Update cadence

  • The dataset is manually verified at least twice per day from official sources.
  • Each update sets lastUpdated and lastVerifiedAt — both are shown in the page banner.
  • Headline counts use the most recent WHO briefing as the primary source. ECDC and CDC updates are used for cross-verification and additional detail (e.g. route or individual nationality where publicly disclosed).
  • If a count differs between sources, we publish the WHO figure and note the discrepancy.

Source hierarchy

  1. WHO Director-General briefings and Disease Outbreak News (primary).
  2. ECDC outbreak page and press updates (cross-verification, EU detail).
  3. CDC About Hantavirus, About Andes Virus, and MV Hondius statements (US detail).
  4. National public-health authorities (Spain, France, the Netherlands, UK, US) when those countries publish primary figures.
  5. Wire services and reputable news outlets are used only to corroborate publicly disclosed individual information (such as nationality of a hospitalised patient) and route stops.

Case definitions

We use ECDC/WHO definitions verbatim where available:

Confirmed case
Symptomatic person with laboratory confirmation of Andes virus by RT-PCR or serology.
Probable case
Symptomatic person epidemiologically linked to a confirmed or probable case without lab confirmation.
Suspected case
Person with exposure history aboard MV Hondius and fever plus respiratory, gastrointestinal, or muscle symptoms.

What we do not do

  • We do not publish individual identifying information about cases.
  • We do not provide medical advice. For symptoms, contact a clinician.
  • We do not replicate AIS / vessel-tracking data; route nodes come from official statements about port calls and medical evacuations.
  • We do not paywall the tracker. All data is open.

Open data

The full machine-readable dataset is available at /data/outbreak.json. Reuse is welcome with attribution.

Corrections

To request a correction or report a source we have missed, please file an issue or email the project (contact details will be added on this page as the project stabilises).

Sources currently used