The source of the outbreak on the MV Hondius, investigated after some passengers have already returned to their countries of origin. Experts: “Hantavirus is spreading more and more”
Argentine authorities are investigating whether their country is the source of the hantavirus outbreak on the MV Hondius amid reports that some of the passengers have already returned to their countries of origin, including the US, where they are being kept under medical observation, according to The Guardian.
The MV Hondius, the cruise ship hit by the hantavirus outbreak, left on April 1 from the Argentinian city of Ushuaia for Antarctica with almost 150 people on board. Authorities are now trying to determine whether the passengers became infected in Argentina, during a stopover or on board the ship.
Argentina is consistently ranked by the World Health Organization (WHO) as having the highest incidence of this rare, rodent-borne disease in Latin America. Andes virus can cause a serious and often fatal lung disease called hantavirus pulmonary syndrome.
On Tuesday, the country's Ministry of Health reported 101 infections since June 2025, roughly double the previous year.
Three passengers on the MV Hondius have tested positive for the Andes virus, according to authorities. Three passengers died, one is in intensive care in a South African hospital, and three others were evacuated from the ship on Wednesday. Another man who left the ship earlier in the journey tested positive in Switzerland.
Argentina announced on Wednesday that it would send genetic material from the Andes virus, as well as testing equipment, to help Spain, Senegal, South Africa, the Netherlands and Britain detect the virus.
There are also concerns about 23 passengers who allegedly disembarked on the island of Saint Helena on April 23, according to Spanish newspaper El País. They are said to have returned to their countries of origin, including the US, where they are under observation in Georgia, California and Arizona, although none are showing symptoms.
“There are 23 people wandering around and until three days ago, no one had contacted them,” said one passenger on condition of anonymity.
The World Health Organization (WHO) states that the first death recorded on board the cruise ship, that of a 70-year-old Dutch man, took place on April 11. His body was disembarked from the ship almost two weeks later in the island of Saint Helena.
His wife, aged 69, traveled by plane from Saint Helena to South Africa; she collapsed at Johannesburg airport and died in hospital on 26 April. The third passenger, a woman of German origin, died on May 2.
Because of the incubation period, which can be up to eight weeks, it was not possible to determine whether the virus was contracted before the April 1 departure, during a scheduled stopover or during the trip to Antarctica.
Public health experts say rising temperatures and changing ecosystems are allowing rodent carriers to thrive in new areas. Human infection usually occurs through exposure to their excrement, urine or saliva.
“Argentina has become more tropical due to climate change, and this has brought disruptions such as dengue and yellow fever, but also new tropical plants that produce seeds for the proliferation of mice,” said Hugo Pizzi, a renowned Argentine infectious disease specialist
The expert warns: “There is no doubt that as time goes on, the hantavirus is spreading more and more.”
WHO Director-General Tedros Adhanom Ghebreyesus recently relayed on X that the organization is monitoring the situation on board in collaboration with the ship's operators and national health authorities. But he adds that, “at this stage, the overall risk to public health remains low.”
