WHO confirms 11 hantavirus cases linked to cruise ship as deaths rise to three

International health agencies are closely tracking a hantavirus outbreak that has now been confirmed on a cruise vessel, with the World Health Organization reporting 11 cases and three deaths among passengers and crew, as concern grows over possible additional infections during ongoing monitoring efforts.

According to the latest update released on May 12, the affected individuals were all aboard the MV Hondius, a Dutch-registered cruise ship that has remained under global surveillance since illness reports first emerged during its voyage in the Atlantic. Health officials confirmed that out of the 11 cases, nine have been verified while two are still under classification as probable.

“Update on #hantavirus: As of 12 May, 12h00 CEST, a total of 11 cases, including 3 deaths, have been reported. Nine of the 11 cases are confirmed, and the other 2 are probable,” WHO said.

The organisation warned that more cases could still be identified due to the conditions on board and the time it takes for symptoms to appear after exposure.

“We expect more cases given the dynamics of spread on a ship and the virus’ incubation period,” WHO said.

Even with the rising case count, WHO maintained that there is no indication the situation has moved beyond the ship or is developing into a broader outbreak affecting the general population.

“At the moment, there is no sign that we are seeing the start of a larger outbreak,” WHO added.

Passengers and crew members who were on the vessel are now being monitored in their respective countries, with health authorities advised to follow a 42-day observation period starting from the date of disembarkation. Governments have also been urged to stay alert for any symptoms among returning travellers.

The outbreak was first flagged through the International Health Regulations reporting system after several passengers developed serious respiratory symptoms while the ship was sailing in international waters. Early assessments had indicated eight cases and three fatalities before the revised figures were confirmed.

Hantavirus is primarily carried by rodents such as rats and mice. Human infection can occur when people inhale particles contaminated with rodent waste or come into contact with urine, droppings, or saliva. In rare situations, certain strains like the Andes virus can spread between people through close physical contact.

WHO Director-General Tedros Adhanom Ghebreyesus said the organisation is working with global partners, governments, and the cruise operator to manage the situation and support those affected, noting that cooperation has been strong across all parties involved.

He added that passengers and crew continue to be followed up in their home countries as part of ongoing containment measures.

WHO has also emphasised that its response focuses on limiting spread while ensuring care and dignity for those affected, with continued coordination to track any new developments linked to the incident.

The situation is being monitored against the backdrop of increased global attention on infectious diseases linked to travel and confined environments, where transmission can spread more easily.

In Kenya, authorities have confirmed that no infections have been reported but say precautionary systems have been strengthened following the international alert.

On May 8, the Ministry of Health said surveillance systems had been activated to reduce any risk of importation and ensure early detection of potential cases.

“There are currently no reported cases in Kenya. The risk to the general public remains low. Health authorities are closely monitoring the situation and taking precautionary measures,” Director-General for Health Patrick Amoth said in a statement.

He added that border health checks, including at airports and seaports, have been intensified, while hospitals have been placed on alert to identify travellers showing compatible symptoms.

The ministry also urged the public to observe hygiene practices and limit exposure to rodents, which are the main carriers of the virus.

On May 9, Principal Secretary for Public Health and Professional Standards Mary Muthoni said counties had been instructed to boost readiness levels and reinforce infection prevention systems despite the low risk classification.

“Following the reported hantavirus outbreak linked to a cruise ship abroad, counties are advised to enhance surveillance, activate emergency preparedness measures, and strengthen infection prevention and control systems,” Muthoni said.

She noted that while the current risk remains low, maintaining vigilance is important to ensure rapid response in case of any imported infection.

Hantavirus infection often begins with flu-like symptoms such as fever, fatigue, muscle pain, and headaches, but can progress into severe respiratory illness known as Hantavirus Pulmonary Syndrome, which may be fatal.

Health officials have advised travellers returning from affected regions or cruise journeys to monitor their health for up to eight weeks and seek medical care immediately if symptoms such as fever or breathing difficulties develop.

As global surveillance continues, Kenya says its focus remains on prevention, early detection, and public awareness while reassuring the public that the current threat level remains low.