Hantavirus Outbreak 2026: Complete Timeline of Cases, Deaths, and Global Response

The 2026 hantavirus outbreak is the most consequential New World hantavirus signal since the 1993 Four Corners cluster, and it is the first event since the 2019 Epuyén outbreak to credibly trigger WHO Emergency Committee deliberations. This page is a living chronology of confirmed events, situation-report milestones, and policy moves. Trade against the consensus on the market book.

Phase 1 — Patagonian index cluster (Feb 2026)

• Feb 12: First confirmed ANDV-positive case hospitalized in Bariloche, Río Negro, Argentina. Forty-eight hours later, four additional cases from the same tourism lodge present at regional hospitals.
• Feb 18: Argentine Ministerio de Salud declares a provincial outbreak; PAHO notified under IHR (2005). Initial provincial count rises to eight.
• Feb 25: First probable household secondary case identified — a contact of the index family with no rodent-exposure history. Whole-genome sequencing matches the lodge cluster.

Phase 2 — MV Hondius export event (Mar 2026)

• Mar 4: A passenger on the cruise ship MV Hondius, which had docked at Puerto Madryn three weeks prior, develops HPS- consistent symptoms en route to the South Sandwich Islands. Vessel diverts to Ushuaia.
• Mar 9: Six additional Hondius passengers and two crew test ANDV-positive by RT-PCR. Vessel placed under enhanced surveillance; passenger contact tracing begins across 11 jurisdictions.
• Mar 14: First fatality among Hondius cases — a 74-year-old passenger with comorbidities. Trade the open question on total Hondius deaths by July 1.

Phase 3 — European autochthonous case (Apr 2026)

• Apr 6: A 41-year-old researcher in Norway hospitalized with bilateral pulmonary edema and thrombocytopenia. ELISA positive for ANDV; the patient denies recent travel to South America.
• Apr 11: ECDC issues a Rapid Risk Assessment highlighting the case as "first European patient without an identifiable exposure pathway." Investigation into possible imported rodents at a Bergen veterinary research facility ongoing.
• Apr 19: Spanish health authorities investigate two suspect cases in Asturias; classified probable. The market "Will a second EU country confirm Andes virus by June 15?" opens for trading.

Phase 4 — WHO mobilization (Apr–May 2026)

• Apr 22: WHO publishes Disease Outbreak News (DON) edition 2026-DON-104 on hantavirus, naming ANDV cluster transmission as a "significant emerging risk."
• May 1: WHO Director-General convenes an Emergency Committee under the IHR (2005) to review whether the situation meets PHEIC criteria. What does PHEIC mean?
• May 6: PAHO releases an enhanced surveillance protocol for ANDV and ramps up bilateral support to Argentina and Chile.
• May 9: Cumulative confirmed ANDV cases globally reach approximately 142, with 47 deaths. The market "Will WHO declare a hantavirus PHEIC by Dec 31?" trades around 35¢ YES.

What to watch next

• Sustained R₀ > 1 — current estimates of inter-person R₀ for ANDV remain below replacement, but a doubling would force a PHEIC.
• Second autochthonous European case — a confirmed infection in another EU member state would reset risk priors.
• Vaccine acceleration — early-phase ANDV mAb and DNA-vaccine candidates can be moved to Phase II under emergency frameworks.
• Travel advisories — escalation from "monitor" to "reconsider non-essential travel" by US State or UK FCDO would shift tourism-economy markets.

Live signals

• Map and ticker on /outbreak.
• Full market book at /markets.
• Authoritative source list at /sources.

This timeline is an editorial aggregation of WHO DON updates, ECDC RRAs, PAHO situation reports and Argentine and Chilean health-ministry bulletins. Dates and counts may be revised as authoritative sources update.