2026 Watch — MV Hondius Cruise Cluster
The current public-health event under active WHO and CDC monitoring is the MV Hondius hantavirus cluster — an Andes-virus investigation linked to a multi-country South American cruise itinerary. As of the most recent WHO Disease Outbreak News update, eleven records are linked to the cluster: eight laboratory-confirmed, two probable, and one inconclusive U.S. repatriated traveler.
Key facts
Following Member State notification on May 2, 2026, WHO has issued three Disease Outbreak News updates describing a hantavirus cluster linked to the MV Hondius cruise vessel and its multi-country South American itinerary. Andes virus is the agent of concern. Eleven records are currently linked to the cluster across confirmed, probable, and inconclusive classifications.
The 11-record total is presented in three separate buckets that should not be silently combined.
CDC is monitoring the cluster through its standard travel-associated surveillance process. The agency has issued clinician-awareness messaging through HAN, asked clinicians to evaluate returning passengers presenting with compatible symptoms, and continues coordinating with state and local health departments. No confirmed U.S. Andes-virus cases linked to the cruise have been reported to date — the single U.S. record remains inconclusive.
The cruise cluster is separate from the U.S. domestic baseline. CDC's Reported Cases of Hantavirus Disease page lists 864 laboratory-confirmed hantavirus pulmonary syndrome cases through 2023 — the most recent year in CDC's annual summary. Most U.S. cases involve Sin Nombre virus and deer-mouse exposure in the rural West, primarily New Mexico, Colorado, Arizona, and California.
Three things to watch as the cluster evolves: whether the inconclusive U.S. record is reclassified after repeat testing, whether additional WHO Member States report linked records, and whether CDC issues updated clinician guidance through HAN. HantaScan tracks each WHO and CDC update as a dated record in the case index.
Authoritative sources are the WHO Disease Outbreak News page (for the cruise cluster), the CDC Hantavirus pages (for U.S. posture), the CDC Reported Cases page (for the cumulative U.S. baseline), and the NNDSS weekly tables (for routine surveillance). If a number on HantaScan disagrees with the underlying source, the underlying source is correct.
CASE INDEX
| Date | Location | Status | Cases | Deaths | Source | Signal |
|---|---|---|---|---|---|---|
| 2026-05-13 | MV Hondius — multi-country South America itinerary International | confirmed | 8 | 3 | WHO | WHO Disease Outbreak News third update on the MV Hondius hantavirus cluster: 11 linked records total — 8 laboratory-confirmed, 2 probable, and 1 inconclusive U.S. repatriated traveler. Andes virus identified as the agent of concern. Investigation continues across multiple Member States. |
| 2026-05-08 | MV Hondius cluster — WHO update International | surveillance | 0 | 0 | WHO | Second WHO Disease Outbreak News update on the MV Hondius cluster raised the confirmed count and described enhanced surveillance for returning passengers across home jurisdictions. |
| 2026-05-05 | United States — CDC monitoring posture United States | surveillance | 0 | 0 | CDC | CDC announced enhanced case-finding for returning MV Hondius passengers and issued clinician-awareness guidance through HAN. No confirmed U.S. Andes-virus cases linked to the cruise to date; the single U.S. record remains inconclusive. |
| 2026-05-04 | MV Hondius cluster — initial WHO report International | surveillance | 0 | 0 | WHO | Initial WHO Disease Outbreak News report on a hantavirus cluster linked to the MV Hondius cruise itinerary following Member State notification on May 2. Two confirmed cases and five suspected cases described at first publication. |
| 2025-03-15 | United States United States | surveillance | 0 | 0 | CDC | CDC and state health departments expanded clinician-awareness messaging on hantavirus pulmonary syndrome following a high-profile case in the rural Southwest that drew renewed national attention. |
| 2023-12-31 | United States — cumulative reported total United States | surveillance | 864 | 311 | CDC | CDC's Reported Cases of Hantavirus Disease page lists 864 laboratory-confirmed cases of hantavirus pulmonary syndrome in the United States through 2023, with historical case-fatality near 36 percent. |
| 2012-08-16 | Yosemite National Park — Curry Village United States | confirmed | 10 | 3 | CDC | Ten confirmed HPS cases were tied to the Signature double-walled tent cabins at Curry Village between June and August 2012. Deer-mouse infestation was identified between the cabin walls; the cabins were dismantled and roughly 22,000 visitors were notified. |
| 1995-07-26 | United States United States | surveillance | 0 | 0 | NNDSS | Hantavirus pulmonary syndrome added to the U.S. list of nationally notifiable diseases, formalizing weekly state-to-CDC case reporting through the National Notifiable Diseases Surveillance System. |
| 1993-11-30 | CDC — Atlanta, GA United States | surveillance | 0 | 0 | CDC | Sin Nombre virus identified as the etiologic agent of the Four Corners outbreak. The deer mouse (Peromyscus maniculatus) confirmed as the primary U.S. reservoir. |
| 1993-05-14 | Four Corners region (AZ · CO · NM · UT) United States | confirmed | 17 | 13 | CDC | Cluster of unexplained adult respiratory deaths in the Four Corners region — primarily on the Navajo Nation — prompted the CDC investigation that led to recognition of hantavirus pulmonary syndrome as a new clinical syndrome. |
Related on HantaScan
Primary Sources