Alarm has been raised on the cruise ship MV Hondius, which was travelling from Ushuaia in Argentina to Cape Verde, after three people on board died following a suspected hantavirus outbreak, while three others have fallen ill, with one already in critical condition. At the same time, questions remain about how the virus initially appeared and spread on the vessel.

According to current available data, a Dutch couple — a 70-year-old man and a 69-year-old woman — are among the dead. The man died upon arrival on the island of Saint Helena, a British territory in the South Atlantic. The woman also fell ill on board and was transferred to South Africa, where she died in a Johannesburg hospital.

The third victim, another man of Dutch nationality, remains on the ship.

According to the WHO, laboratory tests and epidemiological investigations are currently underway, while medical care and support are being provided to passengers and crew.

A British man in critical condition

Meanwhile, a 69-year-old British man is being treated in intensive care in Johannesburg as a confirmed case of the virus. According to South African authorities, he became ill during the journey from Saint Helena to Ascension Island and was subsequently transferred to a private medical facility in Sandton.

Two crew members ill

The operating company Oceanwide Expeditions confirmed that two crew members remain ill and require medical attention. Dutch authorities are already examining the repatriation of the patients from the ship, which is facing a “serious medical situation,” according to the company.

Dutch authorities have taken over coordination of the repatriation operation, if this becomes possible.

The ship remains off the coast of Cape Verde for at least 24 hours without permission to disembark from local authorities, due to concerns about possible spread to the local population.

Possible infection before boarding

Meanwhile, an epidemiologist speaking to the BBC estimated that the passengers who developed symptoms were likely infected before boarding the ship, due to the virus’s long incubation period.

He noted that it is rare for people to contract hantavirus and even more unusual for cases to appear on a cruise ship. He stressed that those showing symptoms must be transported immediately to hospitals with intensive care capability.

He also underlined the need for a thorough investigation to determine whether any preventable factors were involved.

No specific treatment

At the same time, David Safronetz, head of special pathogens at Canada’s National Microbiology Laboratory, told the BBC that there are no specific drugs or vaccines for hantavirus.

As he explained, treatment is mainly supportive care, meaning early diagnosis, immediate medical intervention, and hospitalization in appropriate units.

“There are currently no specific medical interventions to treat the disease,” he concluded.

What is hantavirus

Hantavirus refers to a group of viruses carried by rodents and transmitted to humans mainly through inhalation of airborne particles from dried rodent droppings. Infections usually occur when the virus becomes airborne from urine, feces, or saliva of infected rodents, according to the US Centers for Disease Control and Prevention (CDC). In rare cases, it may also be transmitted through bites or scratches from rodents. In North America, the deer mouse is the most common carrier, according to the Mayo Clinic.

There are two severe diseases caused by hantavirus. The first is Hantavirus Pulmonary Syndrome — the most common strain in the United States. Symptoms often begin with fatigue, fever, and muscle aches, followed by headaches, dizziness, chills, and abdominal issues. If respiratory symptoms develop, the mortality rate is around 38%, according to the CDC.

The second disease is Hemorrhagic Fever with Renal Syndrome, a more severe condition mainly affecting the kidneys.

Only one type of the virus, which is extremely rare, can be transmitted from human to human.