This aerial picture of the cruise ship MV Hondius stationary off the port of Praia, the capital of Cape Verde, on May 3, 2026. Photo: CFP

The World Health Organization (WHO) confirmed on Sunday evening that three people had died in a suspected outbreak of a rare hantavirus infection on a cruise ship in the Atlantic Ocean, with at least one of them confirmed as the victim of hantavirus, the Xinhua News Agency reported.

A Chinese expert noted that hantavirus is neither rare nor emerging. Mature prevention and treatment measures are widely available, so the public need not overestimate its spillover risks.

In a statement to Xinhua, the WHO said it is supporting the response to a public health event involving the cruise vessel sailing in the Atlantic Ocean. To date, one case of hantavirus infection has been laboratory confirmed, and there are five additional suspected cases. Three of the six affected individuals have died, and one is currently in intensive care in South Africa.

The agency said detailed investigations are going on, including further laboratory and epidemiological investigations. Medical care and support are being provided to passengers and crew. Sequencing of the virus is also ongoing, it added.

Hantavirus infections are typically linked to environmental exposure (exposure to infected rodents' urine or faeces). While rare, hantavirus may spread between people, and can lead to severe respiratory illness, requiring careful patient monitoring, support and response, according to Xinhua’s report.

WHO is coordinating with member states and the ship's operators for the medical evacuation of two symptomatic passengers, as well as a full public health risk assessment and support to the remaining passengers on board.

According to earlier reports, South Africa's National Department of Health confirmed that two people have died from an acute respiratory infection on board the cruise ship MV Hondius in the Atlantic Ocean.

Previous reports said the MV Hondius was sailing from Ushuaia in Argentina to Cape Verde when it experienced a severe acute respiratory outbreak, resulting in the deaths of an elderly couple. 

Oceanwide Expeditions, which operates the vessel, confirmed that three passengers died during the voyage and that one passenger is being treated in intensive care in Johannesburg. Two crew members on board also require urgent medical treatment, the company said, according to Fox News.

This outbreak has drawn attention mainly due to the unique conditions on cruise ships. The confined spaces and high population density easily facilitate virus transmission. As a mobile means of transportation, cruise ships may also spread the virus to ports of call, prompting stricter quarantine measures at relevant docking locations after this outbreak, Zhuang Shilihe, a Guangzhou-based medical expert, told the Global Times on Monday.

"The spillover risk of the Hantavirus outbreak on this cruise is relatively manageable. In addition, Hantavirus is not a new strain. Taking China as an example, mature guidelines for virus response, including identification, prevention and treatment, have been established. Vaccines are also available for high-risk groups, so there is no need to overstate its spillover risks," Zhuang said.

Although key details such as the source of infection and the specific transmission chain are still under investigation, past cases and practical experience show that rodents, mainly striped field mice and brown rat, serve as the primary natural host of Hantavirus. Hence, rodent prevention and elimination remain the core of prevention and control work, the expert noted. “Different strains of hantavirus lead to distinct clinical diseases. Some only cause mild flu-like symptoms, while others may trigger hemorrhagic fever with renal syndrome (HFRS) or hantavirus pulmonary syndrome (HPS). Overall, the virus features limited transmissibility and a moderate mortality rate, making excessive public concern unnecessary.”