- A hantavirus outbreak linked to the MV Hondius cruise ship has inspired unproven claims that ivermectin can treat or cure the virus.
- Health agencies say there is no approved cure for hantavirus pulmonary syndrome, and treatment relies on urgent supportive care.
- Ivermectin was widely promoted during Covid-19 despite weak evidence, and experts say there is no clinical evidence that it works against hantavirus.
A serious hantavirus outbreak linked to the MV Hondius cruise ship has already become fodder for a familiar false-cure claim that ivermectin can treat, prevent, or cure a dangerous viral infection.
As of 6 May, the European Centre for Disease Prevention and Control (ECDC) said seven cases had been reported in a hantavirus-associated cluster on the ship, including three deaths, one critically ill person, two symptomatic people, and one person whose status was unknown.
At least two patients tested positive for hantavirus by PCR, and one additional sample tested positive for Andes virus, a South American hantavirus strain that can cause hantavirus pulmonary syndrome and, unusually for hantaviruses, has been documented to spread between people through close, prolonged contact.
That unusual feature has fuelled some alarm online. And with it, it has also revived a Covid-era misinformation pattern presenting ivermectin, an anti-parasitic drug, as a broad antiviral solution.
On X, one post claimed: “Hantavirus is an RNA virus, and ivermectin should work against it.” A former US congresswoman was quick to respond favourably to the claim.
Another user on X, Bret Weinstein, who, among other things, describes himself as “Prof in Exile”, relied on an artificial intelligence conspiracy theory to support his claims:
“When I first saw the hantavirus story I thought: given it’s a single stranded RNA virus, Ivermectin is very likely to work – because IVM is effective with RNA viruses generally. Look what happened when I pursued it with Claude.”
He posted a screenshot of a Claude safety filter being activated after asking the AI chatbot a question about its possible efficacy, and said: “It clammed up, for ‘safety’ reasons. Buckle up!”
But Dr Roger Seheult, a US-based critical care doctor, addressed some of these claims directly, saying he had found “no clinical trials of ivermectin for hantavirus” and no clear in vitro evidence for hantaviruses either.
Evidence does not support ivermectin as a cure for hantavirus
Public health agencies say there is no approved specific antiviral treatment for hantavirus pulmonary or cardiopulmonary syndrome.
The World Health Organisation said that although ribavirin has shown some efficacy against hantavirus haemorrhagic fever with renal syndrome, it has not been effective for hantavirus cardiopulmonary syndrome and is not licensed for its treatment or prevention.
The ECDC’s assessment of the cruise ship cluster was similarly blunt. It said:
No effective antiviral treatment is available; supportive care is key for a better chance of survival.
It recommended early medical evacuation, testing, isolation, appropriate protective equipment, and symptom monitoring, not ivermectin.
The US Centres for Disease Control and Prevention also says there is “no specific treatment” for hantavirus infection. Patients with suspected hantavirus pulmonary syndrome need urgent emergency care, preferably in an intensive care unit, where treatment can include oxygen, intubation, mechanical ventilation and careful management of shock and organ failure.
A throwback to Covid-19
Ivermectin’s reappearance in the hantavirus discussion follows its much larger rise during Covid-19.
During the pandemic, the drug was promoted online and by some political and medical influencers as a treatment for Covid, despite weak and disputed evidence.
The WHO recommended in 2021 that ivermectin be used for Covid-19 only within clinical trials.
The global nonprofit health network, Cochrane, later found no evidence to support ivermectin for treating Covid-19 or preventing SARS-CoV-2 infection. The US Food and Drug Administration also said it had not authorised or approved ivermectin for preventing or treating Covid-19, and that available clinical trial data did not show it was effective against Covid-19 in humans.
Ivermectin misinformation has not only been ideological, but it has also created a market.
South Africa’s medicines regulator, Sahpra, said that during the Covid-19 demand surge, there were reports of illicit ivermectin-containing products entering the South African market and of people using veterinary ivermectin products.
The current hantavirus outbreak is still under investigation, but the claim that ivermectin is a cure is not grounded in clinical evidence. The available public health guidance points instead to rapid recognition, isolation where appropriate, and intensive supportive care.
*At News24, facts matter. This article was produced by the News24 Fact Check Desk and supported by Truth First. If there is something you’d like us to check out, debunk or uncover, send an email to our desk at debunk@news24.com.
