Hantavirus Global Situational Briefing — June 2, 2026

Five of the 18 Americans at Nebraska's National Quarantine Unit have now left the facility to complete their remaining monitoring at home. The Andes virus cluster from the MV Hondius holds at 13 cases and 3 deaths — a count unchanged for a week — as two unrelated domestic hantavirus cases surface in Colorado and Arizona, illustrating the virus's persistent endemic baseline in North America.

By June 2, at least five Americans have departed the University of Nebraska Medical Center's National Quarantine Unit, according to the Associated Press.1 The first two — residents of Orange County and Westchester County, New York — flew home by non-commercial flight on June 1; the remaining three departed subsequently. All five had completed the mandatory 21-day period, remained asymptomatic, and agreed to home-quarantine conditions: staying in their residence, avoiding contact with others, and accepting daily symptom monitoring by state health officials for the balance of the 42-day window.1

Thirteen passengers remain at the facility. Among those staying is Jake Rosmarin of Boston, who told ABC News he will complete the full six weeks in Nebraska. "I have been traumatized by this whole experience. I'm afraid to leave this room until I know that the chance of me getting sick is 0%," he said. Rosmarin added that a key advantage of staying is twice-weekly PCR testing — testing that stops once a passenger returns home.2 The June 22 monitoring endpoint for the May 11 disembarkation cohort remains in force.

It is unclear whether all 13 remaining passengers are voluntarily staying or subject to quarantine orders. Earlier in the outbreak, US health authorities issued federal quarantine orders against at least two passengers who had sought to leave early.

The official case count remains at 13 total — 11 confirmed and 2 probable — with 3 deaths, all of which occurred before May 2. No new case or death has been reported since May 26.3 The ECDC's outbreak page, last updated May 26, notes that "identification of additional cases after former passengers and crew have returned to their home country is expected given the long incubation period of Andes hantavirus."3

The MV Hondius itself, cleared by Rotterdam's GGD on May 30, moved under its own power to Waalhaven 7 on May 31.4 The June 13 Svalbard restart by Oceanwide Expeditions remains on track. The 25 crew members and 2 RIVM medical staff at the Rotterdam quarantine facility have produced no new positive tests.

The 65-year-old French woman remains on ECMO at Hôpital Bichat AP-HP in Paris, now approximately Day 25 of extracorporeal support. The most recent confirmed clinical status — "no further deterioration" — dates to May 28, reported by Wego health travel monitors.5 No updated bulletin has been issued by Santé Publique France since that date. All 26 of her close contacts continue mandatory hospital isolation and have tested negative by PCR on three-times-weekly schedule; they received a supply of favipiravir tablets via the EU–Japan emergency procurement dispatched May 28.

ECMO at this duration carries cumulative risks including circuit-related complications and secondary infection. At Day 25 — and with no functional hantavirus-specific antiviral proven in human trials — clinicians continue supportive care and compassionate-use favipiravir.

Spain's two confirmed cases remain stable.6 Case 1 (70-year-old) continues recovery in the UATAN isolation unit; Case 2 (confirmed May 25 at Gómez Ulla Military Hospital) is asymptomatic. Under Spain's quarantine protocol — 28 days hospital isolation followed by 14 days at home, contingent on negative PCR testing and absence of symptoms — asymptomatic contacts who cleared the 28-day hospital phase would become eligible for home transition around June 7.

Two newly reported domestic hantavirus infections underscore the endemic background of the virus family in North America, entirely separate from the Andes-strain MV Hondius cluster.

Colorado (Arapahoe County): A resident tested positive for Sin Nombre hantavirus, the strain endemic to the US Southwest carried by deer mice (Peromyscus maniculatus). Arapahoe County Public Health confirmed the individual had known local rodent exposure and had not recently traveled outside the area. The patient is recovering well and has no connection to the MV Hondius outbreak.7 Sin Nombre is not transmissible person-to-person.

Arizona (Mohave County): Arizona's health department confirmed a hantavirus case in the Kingman service area. "The source of exposure for the Kingman service area case could not be determined; however local transmission cannot be ruled out," the department stated.8 The strain and clinical outcome were not disclosed in initial reporting. Arizona typically records a handful of hantavirus pulmonary syndrome (HPS) cases annually, primarily from deer mouse exposure in rural settings.

These two cases carry no epidemiological link to ANDV. They are, however, a reminder that HPS surveillance is year-round work distinct from the current ANDV cluster response.

Diagnostic innovation: A preprint published May 26 on medRxiv by a University of Edinburgh-led consortium describes AI-designed PCR assays targeting the ANDV genome, built in response to the MV Hondius outbreak. The assays demonstrated robust detection in early-stage samples, with an adaptable primer design strategy intended to keep pace with viral evolution.9 Nebraska's NQU separately developed its own in-house ANDV PCR test to enable twice-weekly screening of quarantined passengers, a capability not previously available off-shelf.

Lancet EMED commentary: Published June 1, a Lancet European Medical Electronic Devices comment on adaptable laboratory systems for emerging infections uses the 2026 ANDV cluster as a case study, arguing that the outbreak exposed a critical gap between frontline exposure and the deployment of validated diagnostics.10

Oxford/ISARIC study: The prospective clinical study collecting systematic data on confirmed ANDV cases reaches Day 12 on June 2. No interim results have been released. The study is designed to establish baseline clinical parameters — illness progression, immune kinetics, organ involvement — that would inform future trial design.

EU favipiravir supply: The 1,400 Fujifilm tablets dispatched May 28 to France, Netherlands, and Spain via the EC–Japan cooperation mechanism remain the only experimental antiviral in clinical circulation. The European Commission's emergency procurement for additional doses is ongoing. HHS's PREP Act declaration covering favipiravir use in the US remains in force through July 18, 2026 (docket 2026-10539).

WHO's Rt estimate of approximately 0.7 (published in DON 604 on May 28) continues to reflect declining transmission. The risk to the general public globally remains very low, with no evidence of secondary community spread beyond the original MV Hondius exposure network. ECDC's June 1 homepage lists the ANDV outbreak alongside the DRC/Uganda Ebola situation as its two active outbreak priorities.11