Hantavirus: Symptoms, spread, treatment, prevention — the story so far

A Dutch cruise ship, MV Hondius, remains anchored off Cape Verde's coast after a hantavirus outbreak killed three passengers and sickened others among its 147 passengers and crew.

The cruise ship sails Antarctic routes where rodent exposure risks may arise from ports or wildlife contact, according to the Harvard Medical School publication.

Experts at the World Health Organisation (WHO) noted that the 'Andes' strain detected in MV Hondius is a rare hantavirus variant endemic to parts of South America — especially Argentina and Chile.

The MV Hondius cruise ship, site of the recent outbreak, sails Antarctic routes where rodent exposure risks may arise from ports or wildlife contact.

Hantaviruses, part of the Bunyavirales order, cause severe respiratory diseases like hantavirus pulmonary syndrome (HPS) after exposure to infected rodents' urine, faeces, or saliva.

First identified near Korea's Hantaan River, a US strain emerged in 1993's Four Corners outbreak, linked to deer mice booming after drought-rain cycles; it killed several healthy adults in the before the US Centres for Disease Control and Prevention (CDC) identified it.

Early signs mimic flu: fatigue, fever, muscle aches (thighs, back), headaches, chills, nausea, vomiting, and diarrhea, appearing 1-8 weeks post-exposure. Later, coughing and shortness of breath signal fluid-filled lungs, leading to shock.

Most hantaviruses are spread to people from rodents, not from person to person. The Andes variant (suspected here due to South America ties) enables rare person-to-person spread via close contact in prodromal phases, as in Argentina clusters.

WHO experts pointed out that unlike most hantavirus strains, the Andes strain has occasionally shown limited human-to-human transmission among close and prolonged contacts, they added.

WHO experts and officials, including Director-General Tedros Adhanom Ghebreyesus, stress that the overall global risk of an Andes strain outbreak remains "low".

The MV Hondius departed Ushuaia, Argentina, on April 1, 2026, en route to the Canary Islands via remote Atlantic stops including Antarctica and Saint Helena.

Illnesses began April 6 with fever, diarrhoea, and respiratory distress; by May 4, WHO reported seven cases — two confirmed hantavirus, five suspected — including three deaths and one critically ill patient in South Africa.

No specific antiviral exists; ribavirin aids some kidney strains but not HPS. Care focuses on oxygen, ventilation, fluids, and ICU support — early intervention boosts survival from up to 50% fatality.

While there is no specific treatment for hantavirus infection, the Harvard Medical School stated that an antiviral drug called ribavirin is sometimes recommended as it has proven effective for a specific type of hantavirus that causes kidney failure.

"However, it has not been proven effective for lung and heart involvement," according to the article reviewed by Dr Robert H Shmerling, Senior Faculty Editor, Harvard Health Publishing and Editorial Advisory Board Member of Harvard Health Publishing.

There are a number of practical ways to prevent their spread:

Human-to-human spread of hantavirus is "unusual," as per the Harvard Medical School publication.

The WHO has stated that hantavirus infections are not considered a significant risk to the public because of how rare they are and how rarely the virus spreads from person to person.