Hantavirus Global Situational Briefing — May 28, 2026

The ECDC epidemiological tracker for the MV Hondius Andes hantavirus outbreak was updated on 26 May at 15:00 CET, showing a net gain of one case since the previous report 1.

The revised totals: 11 confirmed, 2 probable, 0 suspected, 3 deaths. The death toll has held at three since early May.

Embedded in that single net addition is a methodological change: ECDC has aligned its confirmed-case definition with WHO, now requiring laboratory confirmation by PCR and/or serology rather than relying solely on PCR. Two cases that had previously sat in the probable category were reclassified to confirmed under the new standard. That reclassification and one genuinely new case together account for the shift from the last-reported count of 12 to 13 1.

ECDC notes that the identification of cases after passengers and crew have dispersed globally is expected given Andes virus's incubation window of up to 42 days. The new 13th case is consistent with that dynamic — an individual who was aboard the ship or in close contact with a confirmed case and who tested positive in the days following their return home. Country of notification for Case 13 has not been publicly disclosed.

The EU/EEA general population risk assessment remains very low 1.

The MV Hondius arrived in Rotterdam on May 18; today marks Day 11 of the ship's decontamination and quarantine operation at the enclosed port facility. EWS Group, the contracted cleaning firm, is conducting the full-vessel decontamination. RIVM provided protocols.

As of this briefing, RIVM has published no announcement confirming that the post-decontamination inspection has been completed 3. The inspection is a prerequisite for Oceanwide Expeditions to proceed with its planned June 13 restart; the May 29 and June 5 voyages remain canceled.

The 25 crew members and 2 RIVM medical staff held at Rotterdam's quarantine facility continue their 42-day precautionary monitoring period, which began May 6. The Dutch crew member confirmed as Case 12 on May 22 remains hospitalized and in isolation. The 38 Filipino Overseas Filipino Workers (OFWs), who had tested PCR-negative as recently as May 25, remain in precautionary quarantine per a 42-day protocol 3.

At Radboud University Medical Center in Nijmegen, 12 employees who entered 6-week precautionary quarantine around May 12–13 following a protocol breach are approximately halfway through that window. Blood tests confirmed none are infectious; quarantine continues as a precautionary measure and is expected to end in late June.

The 65-year-old French woman transferred from the MV Hondius remains on ECMO at Hôpital Bichat AP-HP in Paris. She has been on extracorporeal membrane oxygenation for approximately 17 days, based on the last confirmed clinical update from mid-May 4. No new clinical status report has been published by French health authorities since May 12; she is the cluster's most critical active patient.

France's Health Minister Gilles Rist upheld mandatory hospital isolation for all 26 French contacts. All 26 have remained PCR-negative through triple-weekly testing. The policy — backed by epidemiological modeling — is not under review following the Case 12 announcement.

In Spain, the 70-year-old first Spanish patient continues recovery at the UATAN unit under the revised quarantine protocol (28 days inpatient followed by 14 days home isolation for those who test negative and are asymptomatic). A second provisional Spanish positive has not been confirmed; 13 other Spanish contacts have tested consistently negative.

CDC's May 19 situation page states that 18 passengers brought to the Nebraska Quarantine Unit (Nebraska Biocontainment Unit at UNMC) on May 10 are under 42-day monitoring, with no US cases confirmed to date 5. May 31 marks the nominal end of the 42-day quarantine window for the cohort that first entered quarantine on April 19 (when the ship's exposure period began for the earliest contacts); for passengers monitored from their May 10 repatriation, the 42-day window extends to June 21.

Angela Perryman, who has challenged her CDC federal quarantine order in the courts and whose personal quarantine period ends May 31, has not yet filed a formal court complaint as of the last available reporting. The legal question she raised — whether CDC can classify Andes virus under the "severe acute respiratory syndrome" category for quarantine authorization purposes, given that ANDV is not on the official quarantinable disease list — remains unresolved in court.

Three non-passenger US contacts with documented high-risk exposure abroad were transferred to hospital in Kansas prior to May 25 under circumstances that have not been publicly explained. CDC confirmed it is monitoring these individuals closely; none of the 41 US contacts monitored across 11 states have tested positive 5.

Dr. Stephen Kornfeld, whose initial positive PCR was determined to be a false positive, remains in quarantine monitoring in good health.

The HHS PREP Act declaration signed by Secretary RFK Jr. on or around May 22, authorizing compassionate-use access to favipiravir for ANDV disease (Federal Register docket 2026-10539), remains in effect through July 18, 2026. The declaration covers favipiravir only and applies specifically in the MV Hondius cluster context. No clinical data on favipiravir's efficacy in human ANDV infection has been published; the rationale rests on animal model data showing 100% survival in rodents challenged with lethal Andes virus doses. The teratogenicity risk profile of favipiravir remains a noted constraint on its use.

No compassionate-use application has been publicly reported since the declaration was issued.

The Oxford Partnership for Severe Infections (PSI)/ISARIC standardized clinical study, which enrolled 20+ British nationals following their repatriation from the MV Hondius, is in its seventh day. Institutions involved include the Universities of Oxford, Liverpool, Edinburgh, and Glasgow, with laboratory support from UKHSA RIPL and the MRC Centre for Virus Research at Glasgow. No interim data have been released.

The 150 live-trap survey deployed May 19–21 across Ushuaia and Tierra del Fuego National Park, targeting the rodent reservoirs potentially linked to the ship's zoonotic introduction, has produced samples that are being analyzed at the Malbrán Institute in Buenos Aires. Results are expected within approximately four weeks of collection, placing a probable reporting window in mid-to-late June. A second Argentine field sampling effort in the Ushuaia area is also under way. The genomic evidence from the ship's cluster points to a single zoonotic introduction with ≤1 SNP divergence, consistent with a point-source exposure in Argentina.

Argentina's National Epidemiological Bulletin (BEN) for Epidemiological Week 19 (SE19), expected around May 26, had not been published on accessible government servers as of this writing. The SE18 count stood at 102 cases and 32 deaths. Chile reported 41 cases and 14 deaths (34% case-fatality rate) as of the most recent bulletin, and Bolivia recorded 4 Andes-strain cases near the Argentine border, with no update since the prior reporting cycle.

The next concrete milestone is May 31, when the earliest US quarantine cohort's window nominally closes and Perryman's quarantine ends. The RIVM inspection outcome — which unlocks the June 13 restart — is the outstanding operational bottleneck in the Netherlands. France's ECMO patient remains the most acute clinical marker globally.