Hantavirus strain confirmed

The hantavirus-linked outbreak aboard the MV Hondius has entered a more serious phase after authorities confirmed that two local cases involve the Andes strain, the only known hantavirus variant capable of limited human-to-human transmission under conditions of close contact.

The development coincided with mounting political and public health tension in Spain, where the leader of the Canary Islands rejected plans for the virus-hit vessel to dock in Tenerife despite Spain’s central government granting permission for the ship to enter port.

Fernando Clavijo, the president of the Canary Islands regional government, said there was insufficient information to reassure the public or guarantee safety and requested an urgent meeting with Spanish Prime Minister Pedro Sánchez over the decision.

The Dutch-flagged expedition vessel remains off the coast of Cape Verde after a voyage that began in southern Argentina and travelled through remote South Atlantic territories before heading towards Europe.

At least eight suspected cases linked to the outbreak have been identified, including three deaths and three laboratory-confirmed Andes strain infections. A British national is in ICU in Johannesburg, while three people associated with the outbreak are being medically evacuated to the Netherlands.

The department of health confirmed that laboratory testing conducted by the National Institute for Communicable Diseases (NICD) identified the Andes strain in two passengers linked to the vessel: a Dutch woman who died after collapsing at OR Tambo International Airport and a British man currently receiving treatment in Johannesburg. The two Dutch passengers were married and had reportedly travelled in South America before boarding the vessel.

According to the NICD, hantavirus pulmonary syndrome is a rare but severe respiratory disease transmitted primarily through inhalation of particles contaminated with rodent urine, droppings or saliva. Initial symptoms can include fever, headaches, muscle pain and gastrointestinal illness before progressing rapidly to respiratory distress.

The confirmation of the Andes strain changes the investigation because it is the only known hantavirus variant associated with limited human-to-human transmission, although health authorities stress that such spread is rare and generally limited to prolonged, close contact.

“This is the only strain that is known to cause human-to-human transmission but such transmission is very rare and only happens due to very close contact,” the health ministry confirmed in a parliamentary presentation.

The World Health Organisation has indicated that investigators suspect limited transmission might have occurred among close contacts onboard the vessel, including cabin-sharing passengers and caregivers.

Dr Maria Van Kerkhove of the WHO said investigators believed the original infections occurred before passengers boarded the vessel in Argentina, potentially during wildlife-related activities associated with the expedition voyage near Ushuaia.

“With the timing of the incubation period of hantavirus, which can be anywhere from one to six weeks, our assumption is that they were infected off the ship,” she said. 

She said investigators nevertheless believed there “may be some human-to-human transmission” among close contacts onboard, particularly between individuals sharing cabins.

The outbreak has shifted from a suspected environmental exposure event into a more complex investigation involving possible close-contact transmission.

The vessel’s route has become central to that investigation. The cruise travelled from Ushuaia in southern Argentina through isolated South Atlantic islands, including St Helena and Ascension Island, before heading north towards Europe. Authorities are assessing whether exposure occurred before boarding, during shore excursions or onboard.

Expedition cruises present particular challenges for health authorities. Although ships operate as controlled environments, the voyages often involve contact with remote ecosystems and wildlife habitats where environmental exposure risks are more difficult to predict or contain.

The outbreak response onboard has intensified in recent days, with symptomatic passengers isolated, additional protective equipment supplied to medical personnel and close contacts monitored as the vessel prepares to dock in the Canary Islands.

For local health authorities, the immediate response has focused on contact tracing and containment within a limited exposure group. Officials maintain that the broader public risk remains low and stress that hantavirus differs fundamentally from Covid-19 in that it is not easily transmissible between people and does not pose the same pandemic threat.

Health Minister Aaron Motsoaledi has stressed that hantavirus is well understood and significantly less transmissible than Covid-19.

The country previously recorded a laboratory-confirmed imported hantavirus case in 2021 involving a patient who had travelled to Croatia and was believed to have been exposed in a rural setting linked to a horse stable. 

Globally, hantavirus infections are unevenly distributed. The haemorrhagic form of the disease is more commonly reported in Asia and Europe, while hantavirus cardiopulmonary syndrome, the severe respiratory form now under investigation aboard the Hondius, is more frequently recorded in the Americas. 

The outbreak is being managed through coordination between the WHO, local authorities and European governments connected to the vessel’s route and passengers.

Spain’s health ministry said it agreed to receive the vessel after requests from the WHO and the European Union “in accordance with international law and humanitarian principles”.

But opposition from Canary Islands authorities has exposed growing tension between humanitarian obligations, public anxiety and outbreak management.

For now, there is no evidence of sustained local transmission. But confirmation of the Andes strain has altered the nature of the outbreak, placing greater focus on close-contact exposure and intensifying scrutiny of how rare but high-fatality infections move through global travel systems.

All you need to know about  the virus outbreak

The rare virus outbreak linked to an expedition cruise ship has left three people dead and triggered a multi-country public health response. 

Here’s what we know:

What happened on the MV Hondius?

The Dutch-flagged expedition cruise ship MV Hondius departed from southern Argentina and travelled through remote South Atlantic islands before heading towards Europe. During the voyage, several passengers developed severe flu-like symptoms, with at least seven suspected cases linked to the outbreak. 

Three people have died, including a Dutch passenger who collapsed at OR Tambo International Airport while in transit through South Africa.

What is hantavirus?

Hantaviruses are a group of viruses usually transmitted to humans through contact with infected rodent urine, droppings or saliva. 

According to the National Institute for Communicable Diseases, hantavirus pulmonary syndrome is a rare but severe respiratory disease that can progress rapidly to respiratory failure. 

Symptoms often begin with fever, headaches, muscle pain and gastrointestinal illness before affecting the lungs.

Why does the Andes strain matter?

South African authorities confirmed that two passengers linked to the outbreak tested positive for the Andes strain of hantavirus. This is significant because it is the only known hantavirus variant associated with limited human-to-human transmission. 

Health authorities stress that such transmission is rare and generally requires prolonged, close contact between people. 

What is South Africa’s connection?

South Africa confirmed two cases linked to the vessel. 

A Dutch woman died after collapsing at OR Tambo International Airport, while a British man remains in intensive care in Johannesburg. 

The Department of Health has launched contact tracing in Gauteng involving people who might have had close contact with the infected passengers.

Is the public at risk?

Health authorities say the broader public risk remains low. Unlike Covid-19, hantavirus is not easily transmitted between people and does not pose the same pandemic threat. 

The World Health Organisation said investigators believe the original infections probably occurred before passengers boarded the ship, possibly during wildlife-related activities in Argentina. 

Why is the ship at the centre of political tension in Europe?

The outbreak has triggered a dispute in Spain after the leader of the Canary Islands rejected plans for the vessel to dock in Tenerife, arguing there was insufficient information to guarantee public safety. 

Spain’s central government nevertheless granted permission for the ship to dock after requests linked to international health and humanitarian obligations.

Has SA seen hantavirus before?

Yes. South Africa recorded a laboratory-confirmed imported hantavirus case in 2021 involving a patient who had travelled to Croatia and was believed to have been exposed in a rural setting. 

What happens next?

Authorities are continuing laboratory testing, contact tracing and epidemiological investigations linked to the vessel and its passengers. 

The key questions remain where the initial exposure occurred and whether limited onboard transmission took place among close contacts.