Hantavirus Global Situational Briefing — May 29, 2026

The MV Hondius cluster has now held at 13 cases for three days, and the clearest story on May 29 is not what happened — but what is about to. RIVM's post-decontamination inspection of the ship remains pending at Day 12, the result that will determine whether Oceanwide's June 13 restart survives; 18 Nebraska quarantine passengers approach the May 31 milestone with no CDC early-release decision disclosed; and France's ECMO patient is entering a third week on life support with no public update since May 12. The outbreak is not in remission. It is in a watching phase — and the next 72 hours will start to clarify several of the open threads.

Global case count

As of the most recent epidemiological update from ECDC (26 May 2026, 15:00 UTC), the global total stands at 13 cases — 11 confirmed and 2 probable — with 3 deaths 1. No new cases have been reported since Case 13 was identified on May 26. No new deaths have been recorded since May 2.

Hantavirus outbreak epidemiological curve showing case onset distribution — MV Hondius outbreak epidemiological curve as of May 13, 2026 2

The two cases reclassified to confirmed on May 26 were originally classified as probable under the earlier case definition; ECDC revised the definition in alignment with WHO, which now requires laboratory confirmation by PCR and/or serology 1. The revision does not reflect new infections — it reflects reclassification of existing probable cases. The case fatality ratio remains at 23% (3 deaths among 13 total cases) against a baseline HCPS mortality of 40–50% for Andes virus in historical South American data.

The WHO's most recent formal Disease Outbreak Notice (DON-601, 13 May 2026) described 11 total cases at that time, and a new formal DON incorporating Cases 12 and 13 has not yet been published 2.

Open thread tracker

The table below summarizes the status of key clinical and operational threads as of May 29 morning, based on the last confirmed public update for each 1 3 4:

Thread	Last update	Status
Global case count	ECDC, 26 May	13 total (11 confirmed + 2 probable), 3 deaths
Rotterdam decontamination	RIVM, 18 May	Day 12; ongoing; EWS Group
RIVM post-decon inspection	—	Pending; no date given
Oceanwide June 13 restart	Oceanwide	Contingent on RIVM inspection clearance
Rotterdam quarantine (25 crew + 38 OFWs)	RIVM, 22 May	All PCR-negative; quarantine ongoing
Case 12 (Dutch crew)	RIVM, 22 May	Confirmed; hospitalized
France ECMO patient	SPF/ECDC, ~12 May	~Day 20 ECMO; no update
France 26 contacts	ECDC, 26 May	All PCR-negative; mandatory hospital isolation
Spain Case 1	ECDC, 26 May	Recovering; revised 42-day protocol
Spain Case 2 (provisional)	ECDC, 26 May	Still unconfirmed
Nebraska 18 NQU passengers	CDC, 19 May	Asymptomatic; May 31 milestone
Kansas 3 non-passenger contacts	CDC, week of 25 May	Hospitalized; reason undisclosed
Oxford/ISARIC study	Activation, 21 May	Day 8; no data published
WHO formal DON (Cases 12–13)	—	Still pending
ECDC CDTR Week 22	—	Not yet published
HHS PREP Act (favipiravir)	HHS, 22 May	In force through 18 July 2026

Rotterdam: Day 12, inspection still pending

The MV Hondius has been undergoing decontamination by EWS Group at the Port of Rotterdam since May 18, when the ship docked with 27 crew and medical personnel aboard 3. All 27 tested negative for Andes virus on the day of docking.

Rotterdam decontamination entered Day 12 on May 29. RIVM's post-decontamination inspection of the ship — the precondition for Oceanwide to resume operations — has not been completed or cleared. Oceanwide has confirmed June 13 as its current restart target, with the May 29 and June 5 sailings already canceled. Whether June 13 holds depends entirely on the inspection result.

The 25 crew members held at the Rotterdam quarantine facility and the 38 Filipino Overseas Foreign Workers (OFWs) who tested PCR-negative are in Day 12 of their 42-day precautionary quarantine. RIVM has stated it will issue public updates only when a positive test result occurs; the absence of any announcement since May 22 is consistent with all ongoing tests remaining negative 3.

The Case 12 patient — a Dutch crew member who was in home quarantine and tested positive on May 22 — remains hospitalized, confirmed by joint RIVM/Erasmus MC testing 3.

United States: May 31 approach

View from cruise ship deck over ocean — MV Hondius passengers were repatriated to the US on May 10; 18 are currently at the Nebraska Quarantine Unit approaching the May 31 nominal quarantine window 4

The 18 MV Hondius passengers brought to the Nebraska Quarantine Unit (NQU) at the University of Nebraska Medical Center on May 10 are approaching the nominal end of their 42-day quarantine period — May 31 marks the outer bound for the earliest cohort. CDC's most recent public situation update (May 19) confirmed all 18 remain asymptomatic and under evaluation, but has not disclosed any early-release decision or protocol for the May 31 date 4.

Angela Perryman — whose quarantine also nominally ends May 31 — has an ongoing legal challenge to her CDC isolation order. No formal court filing has been recorded as of the last available reporting.

Three non-passenger contacts in Kansas — individuals with documented high-risk exposure to the virus abroad, not connected to the MV Hondius passenger manifest — were transferred to hospital earlier this week for reasons that have not been publicly explained. No symptoms have been disclosed, and CDC is closely monitoring the situation. This remains one of the more opaque threads in the US response.

A total of 41 people across 11 US states are under CDC monitoring. Zero US cases have been confirmed. One false-positive result (Kornfeld) was previously identified and that individual remains in good health under quarantine monitoring.

France and Spain: prolonged cases, no new developments

The 65-year-old French woman who contracted HCPS during the voyage remains on extracorporeal membrane oxygenation (ECMO) at Hôpital Bichat-Claude Bernard (AP-HP) in Paris. She has been on ECMO support for approximately 20 days as of May 29. The last confirmed public update from French health authorities on her clinical status was May 12 1.

All 26 contacts in France have tested PCR-negative, tested three times per week under mandatory hospital isolation. French Health Minister Rist upheld mandatory hospital isolation for all 26 contacts — a policy that, given the continued negativity of their tests, is now entering its third week.

In Spain, the first confirmed case — a 70-year-old patient — continues recovering at the UATAN (Tropical and Travel Medicine Unit) at Hospital Carlos III in Madrid, now under a revised protocol of 28 days in hospital followed by 14 days of home monitoring. The second provisional positive in Spain remains unconfirmed, with 13 other Spanish contacts consistently negative.

Radboudumc and other European threads

Twelve Radboudumc (Nijmegen, Netherlands) employees have been in six-week precautionary quarantine since approximately May 12–13, following a protocol breach during the treatment of an early Hondius patient. Their quarantine is scheduled to end in late June. No positive tests have been reported from this cohort.

The Canadian case (Yukon resident, now stable in Victoria, British Columbia) and the Swiss case (still hospitalized) have produced no new updates.

Oxford/ISARIC clinical study

The Oxford/ISARIC Multi-Strain HCPS clinical characterization study, activated at the outbreak's onset, enters Day 8 of data collection on May 29. The study is tracking more than 20 British nationals who were passengers on the MV Hondius. No interim data have been published; the study protocol requires systematic clinical data collection before any results are released. This study is the most likely source of systematic clinical outcome data on the current strain's severity profile.

HHS PREP Act and treatment pipeline

HHS Secretary Kennedy's targeted PREP Act declaration for Andes hantavirus — specifically covering favipiravir — remains in force through July 18, 2026 (Federal Register docket 2026-10539) 2. No compassionate-use application for favipiravir has been publicly reported, despite the France ECMO patient being the most clinically obvious candidate.

There is no licensed antiviral or vaccine for HCPS. Treatment remains supportive: ventilation, ECMO in severe cases, careful fluid management. The PREP Act declaration enables emergency deployment without the standard authorization pathway if a clinician requests favipiravir for an active Andes virus case.

Americas endemic background

Rat on surface — hantavirus rodent reservoir — Rodent host surveillance is ongoing in Tierra del Fuego — the likely geographic source of the outbreak spillover 3

Argentina's Boletín Epidemiológico Nacional (BEN) Week 19 (covering through late April) reported 102 endemic hantavirus cases and 32 deaths in the current season. The Week 19 bulletin was expected to be available around May 26; as of the time of this briefing, the Week 20 data had not yet become accessible through the Argentina Ministry of Health portal. The Argentina rodent survey from the Ushuaia/Tierra del Fuego region (150 box traps, samples collected May 19–21) remains under analysis at the Malbrán Institute; results are expected in mid-to-late June.

Chile's current season stands at 41 cases and 14 deaths (34% CFR), Bolivia has reported 4 Andes-strain cases near the Argentine border with no new update.

Regulatory and public health architecture

The WHO does not currently consider the MV Hondius outbreak to meet PHEIC threshold — global risk remains assessed as low, with person-to-person transmission of Andes virus requiring prolonged close contact and containment measures already reducing exposure pathways 2. The ECDC CDTR Week 22 report, which would normally cover the May 23–29 period, had not been published as of this briefing's production time. The ECDC hantavirus outbreak tracker remains the most current and accessible official data feed.

An important contextual note: WHO declared the DRC/Uganda Bundibugyo Ebola outbreak a PHEIC on May 17, drawing significant global public health response resources. With 246 suspected cases and 80 deaths as of that declaration, the Ebola PHEIC is absorbing emergency capacity across multiple international response bodies — a factor that may affect the pace of formal institutional updates on hantavirus, even as field surveillance continues.

What to watch next

RIVM post-decontamination inspection result: Pending; determines the June 13 Oceanwide restart
CDC May 31 quarantine decision: Whether the Nebraska 18 and Angela Perryman are released on schedule, held longer, or moved to outpatient monitoring
Kansas hospital contacts: No disclosed symptoms or test results; the most unexplained thread in the US response
France ECMO patient update: Day 20+ on life support; no clinical communication since May 12
Spain Case 2 resolution: Consistently negative contacts suggest it will not confirm, but no official close-out has been announced
ECDC CDTR Week 22: Expected later today or early next week
WHO formal DON update for Cases 12–13: Still pending — the official case count at WHO's website lags the ECDC tracker
Oxford/ISARIC preliminary findings: No timeline published, but Day 8+ data collection is underway
Argentina BEN Week 20: Expected to contain updated endemic season case counts