2JUN

Hondius hantavirus cluster hits 12 cases

2 min read

09:17UTC

The Andes hantavirus cluster aboard the cruise ship MV Hondius reached 12 cases and three deaths, with passengers now traced across 12 countries after the ship docked at Rotterdam.

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Key takeaway

A person-to-person hantavirus aboard one ship has become a 12-country tracing exercise.

The Andes hantavirus cluster aboard the cruise ship MV Hondius reached its 12th case, with three deaths, as of 24 May, according to the European Centre for Disease Prevention and Control (ECDC) ¹. The ship docked at Rotterdam on 18 May, and passengers have now been traced across 12 countries; ECDC's surveillance update confirmed one new case since 12 May, when the count stood at 11 across six countries .

Andes virus is the only hantavirus known to pass between people, which is why a single voyage becomes an international tracing exercise rather than a contained shipboard event. The slowing pace, one new case in twelve days against the earlier risk upgrade from low to moderate , suggests the cluster is being tracked rather than running ahead of the response. The open question is the dispersed cohort: a dozen national health systems now each hold a fragment of one passenger manifest.

Deep Analysis

In plain English

The MV Hondius is an Antarctic cruise ship. After its last voyage from Ushuaia, Argentina, several passengers tested positive for Andes hantavirus, a rare lung disease caused by a virus found in rodent droppings in South American wilderness areas. Andes hantavirus is unusual because, unlike other hantaviruses, it can spread between people in close household contact, which is what made this cluster particularly concerning when it first emerged. As of 24 May 2026, 12 passengers are confirmed or probable cases, three have died, and passengers have been traced to 12 countries. The ECDC (the EU's disease agency) confirmed only one new case since 12 May, which suggests the cluster is slowing. People who were on the ship are being monitored, typically for 21 days after last exposure.

Source Landscape

This story draws on neutral-leaning sources

Consensus view: UKHSA's Emerging Infections and Zoonoses team assessed that one additional case since 12 May, against a backdrop of passengers traced to 12 countries, indicates the cluster is plateauing rather than amplifying; Andes virus (the only hantavirus capable of person-to-person transmission) has a 14-38-day incubation window, and with the ship docking at Rotterdam on 18 May, the 21-day post-disembarkation monitoring window extends through early June.

Counter-view: The ECDC's Rapid Risk Assessment noted that the three-case discrepancy between ECDC's count of 11 and WHO DON 600's earlier figure of 8 reflects differing national case-definition thresholds rather than reporting lag alone; the same definitional inconsistency means the 12-case figure as of 24 May may undercount probable cases in countries applying stricter criteria.

Key tension: Whether the single new case since 12 May represents genuine plateau or surveillance lag in countries where suspected cases have not been laboratory-confirmed.

Sources:European Centre for Disease Prevention and Control

Mentions:MV Hondius →ECDC →Rotterdam →Ushuaia →DON 600 →Argentina →UKHSA →World Health Organization →Andes virus →

First Reported In

Update #4 · Ebola triples, response misfires

European Centre for Disease Prevention and Control· 24 May 2026

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Causes and effects

This Event

Hondius hantavirus cluster hits 12 cases

A person-to-person hantavirus on a ship turns a single voyage into a 12-country contact-tracing problem.

Led to

Ship hantavirus cluster is winding down

DON604's 13-case total is an increment from the 12-case cluster recorded at ID:3601, confirming the downward trajectory.

Occurred 28 May 2026

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Different Perspectives

Imperial College London / Cori and Ferguson

Anne Cori and Neil Ferguson place the case-fatality ratio at 30 to 40 per cent and read the 6.8-to-1 suspected-to-confirmed ratio as evidence that the laboratory figure understates true lethality. Many people die before a swab reaches them.

Uganda / Diana Atwine

Diana Atwine's ministry traced the imported Kampala index case and leant on protocols rehearsed in Uganda's 2022 Sudan ebolavirus response, which contained 142 cases in 113 days without a vaccine. Nine confirmed cases now test whether that playbook holds across two districts.

United States / HHS

Washington imposed a 21-day entry ban on DRC, Uganda and South Sudan nationals against WHO advice, and sought a 50-bed quarantine site in Nairobi that a Kenyan court suspended on 29 May. The posture rests on a thin federal bench with vacant senior public-health roles.

WHO / Tedros Adhanom Ghebreyesus

Tedros Adhanom Ghebreyesus called the outbreak 'outpacing us' on 25 May and visited Ituri on 28 May, arguing that stopping transmission depends entirely on humanitarian access. WHO opposes any restriction of travel to or trade with DRC or Uganda.

Africa CDC / Jean Kaseya

Jean Kaseya declared the continental emergency before WHO and opposed the US travel ban as punishment by passport rather than by exposure. The Africa CDC raised nearly $500 million in days and frames the response as African-led, coordinated from Addis Ababa rather than waiting on Geneva.

European Union / ECDC

ECDC activated an EU Health Task Force, assessed European Bundibugyo import risk as very low, and flagged the recombinant clade Ib/IIb mpox strain in four countries as a surveillance watch item. Both calls reflect the same post-2024 IHR mandate: ECDC acts as a continental early-warning layer rather than waiting for WHO Disease Outbreak News guidance.