Explainer - The internet is filling with panic about hantavirus, but is it really as dangerous as Covid-19? Here's what we know so far.
Three deaths and several infections on a cruise ship off South America has raised alarms for many, in a world where some are still mentally and physically recovering from the Covid-19 pandemic.
"This is not going to be another coronavirus pandemic, from all we know about this agent," said epidemiologist Michael Baker, a man who knows his pandemics and was one of New Zealand's most prominent experts during Covid-19.
"This is not another Covid," World Health Organisation Director-General Dr Tedros Adhanom Ghebreyesus has also said. "The current public health risk from hantavirus remains low."
US passengers from the Dutch flagged hantavirus-stricken cruise ship MV Hondius are transferred by boat to the industrial port of Granadilla de Abona on the island of Tenerife in Spain's Canary Islands on 10 May, 2026. Photo: AFP
Three people have died and at least six others appear to be infected after an outbreak of hantavirus on the cruise ship MV Hondius, which was travelling around South America last month.
Passengers on the cruise ship have been evacuated in the Canary Islands. One New Zealander has been confirmed to be among them.
That person will eventually return home.
The Ministry of Foreign Affairs and Trade confirmed that "we are providing consular assistance to a New Zealander on board the MV Hondius. This will include repatriation assistance."
MFAT indicated no further information on the New Zealander would be provided for privacy reasons.
"We currently have no reason to believe that any New Zealanders have contracted hantavirus," said Dr Richard Jaine, deputy director of public health for the Ministry of Health.
"However, it is important that we respond appropriately and take all possible steps to manage any potential risk to individuals or the public."
The person may likely face precautions on their return to New Zealand.
"Depending on the risk it is possible this may also include a period of quarantine for any exposed individual on their return to New Zealand."
Hantavirus is typically spread by the inhalation of contaminated rodent droppings.
This particular strain, the Andes virus, is endemic to Argentina, and is the only strain of hantavirus that has been known to have human to human transmission - typically through very close contact such as sharing a bed or food.
Its symptoms typically include fever, headache, muscle aches and gastrointestinal symptoms.
Hantavirus cardiopulmonary syndrome (HCPS), a severe respiratory illness that can develop, has a case fatality rate up to 50 percent. It's the same thing that killed Betsy Arakawa, the wife of the late actor Gene Hackman, last year.
Dr Michael Baker Photo: Supplied / Department of Public Health
"The (hantavirus) in the Americas are particularly dangerous because they have a fatality rate of about 40 percent," Baker told RNZ Afternoons. "They're very unpleasant infections if you get them."
No vaccines or specific treatments exist for hantavirus, but quick hospital care can often prevent symptoms turning deadly.
Hantaviruses are found in small mammals such as rats, mice, voles, shrews and lemmings, but no New Zealand rodents carry these viruses, University of Auckland associate professor of infectious diseases Dr Mark Thomas said.
"The only way a New Zealand resident could become unwell with a hantavirus infection would be as the result of travel to a country where the virus is present."
WHO has said the investigations so far suggest possible exposure to rodents during bird watching activities.
"A Dutch couple, who unfortunately have now died, probably got infected in Argentina, and the other thing that was very bad luck was that the Andean species of this hantavirus is the only one that has occasionally caused person to person transmission," Baker said.
The virus comes from infected rodents. Photo: 123RF
How is it transmitted?
Hantavirus is contracted from direct contact with urine, droppings or saliva of infected rodents, or rarely through rodent bites.
But the Andes variant has shown some ability to move between humans in certain conditions.
"Andes virus has demonstrated limited human-to-human transmission in previous outbreaks, typically occurring among close contacts and within household settings, generally requiring prolonged close exposure," WHO's database states.
However, Covid-19 is a far more efficient airborne respiratory virus that spreads much easier than hantavirus does.
Human-to-human transmission of hantavirus is rare and requires prolonged and direct exposure to a case, Jaine said.
"This isn't like the flu or Covid-19."
Cruise ships have often been incubators for diseases and outbreaks.
Baker said the combination of the Andes hantavirus and cramped quarters on board a ship have made for a "really bad sequence of events".
"The ship environment presents an increased risk due to close living quarters, shared indoor spaces, prolonged exposure, and frequent interpersonal interactions, all of which may facilitate transmission," WHO wrote.
Health authorities in several countries have also been tracking passengers who had already disembarked and anyone who may have come into contact with them.
The lengthy incubation time of the virus - as long as eight weeks - could also complicate efforts to contain the disease.
The general consensus for now is that while it's worrying and health authorities are paying close attention, this isn't the same kind of quick-spreading disease Covid was.
"It has all those echoes from a very tough period in our history," Back said, with an infection that's come from an animal to humans. But it's not the same kind of illness.
"It's very different. They're usually very hard to catch. There are several hundred cases a year but they are linked to rodents."
The images of masked medical workers and return of contract tracing is bringing back memories of the pandemic for many people. "Covid PTSD" is a real thing, with people anxious about a return to lockdowns and cracking dad jokes on social media about stocking up on toilet paper.
So far, the advice is not to panic.
"This is not the start of an epidemic. This is not the start of a pandemic," Dr Maria Van Kerkhove, director of WHO's Department of Epidemic and Pandemic Management, said at a press conference.
"I think it's very important that listeners are not overly concerned about this particular outbreak ... It is being very well managed," Baker said.
Viruses do mutate, so health authorities are taking the hantavirus situation very seriously, Baker said.
"They'll certainly be looking at it to see if it has changed in any way."
For the passengers on the ship, "precautions being taken are very intense," he said.
"Anyone being evacuated is going to be treated as if they are quite infectious."
WHO's emergency alert and response director Abdi Rahman Mahamud told AFP he believed any further spread would be "a limited outbreak" if "public health measures are implemented and solidarity shown across all countries."
WHO has said it advises against implementing any travel or trade restrictions based on current information about the hantavirus.
The majority of the approximately 150 passengers and crew on board the cruise ship appear not to have contracted the virus.
"If it was highly infectious it wouldn't just be maybe half a dozen people infected on this ship," Baker said.
"You'd see a high proportion of people on board showing some evidence of infection."
-RNZ