Topline
Doctors and public health experts are warning against a viral claim that the anti-parasitic drug ivermectin could treat hantavirus, the disease behind a cruise ship outbreak that has killed three people and sickened a handful of others.
A health worker shows a box containing a bottle of Ivermectin.
AFP via Getty Images
Key Facts
Dr. Dana Mazo, an infectious disease specialist at Tisch Hospital in New York, told Forbes there is no data to support the claim ivermectin can treat hantavirus in human patients and is warning against such “misinformation” that can “cause confusion, prevent people from following the recommendations that can actually help them and can hurt people.”
The idea of treating hantavirus with ivermectin, most commonly used as a dewormer for livestock, has spread online after Dr. Mary Talley Bowden, a doctor who was reprimanded by the Texas Medical Board for prescribing the medicine to a COVID patent in 2021, posted it to X in a tweet that has been viewed 3.5 million times.
Bowden on Wednesday posted that hantavirus is an RNA virus—a category which Mazo says encompasses a “huge group” of very differently behaving viruses—and therefore ivermectin should work against it, but while the drug has shown promise in inhibiting viral replication of RNA viruses in some lab settings, those results have not been proven to work in human patients.
Mazo says it is dangerous to suggest a scientific test in a lab setting will translate to human patients without further study and, that in this case, there has not been any testing of ivermectin against hantavirus specifically, even in lab tests.
Bowden’s claim was amplified online by former MAGA Rep. Marjorie Taylor Greene, who has also suggested with no evidence that pharmaceutical companies somehow manipulated the hantavirus to create an opportunity for profit via future vaccine development.
Other medical professionals also quickly rejected Bowden’s claims: Dr. Krutika Kuppalli, an internal medicine professor at the University of Texas Southwestern Medical Center, said there is “no clinical evidence” supporting ivermectin kills hantavirus and Dr. Neil Stone, infectious disease doctor at the University College London Hospitals in the United Kingdom, tweeted “Ivermectin does NOTHING to treat Hantavirus.”
Crucial Quote
“There are a lot of cases where ivermectin is the right drug, but certainly not hantavirus cases, where we have no evidence it will help,” Mazo said.
Key Background
Ivermectin is an antiparasitic drug that revolutionized the treatment of debilitating diseases, specifically those caused by roundworm parasites. Its discovery won two scientists a Nobel Prize in Physiology or Medicine in 2015 and it has a reputation as a “wonder drug” for parasites. The FDA approves its use for humans in very specific, limited conditions. During the COVID-19 pandemic, a few small studies and observational reports suggested ivermectin could lead to lower mortality and faster recovery for patients, but those studies were fraught with statistical errors and other problems and one influential study was later withdrawn after allegations of fabrication and plagiarism. Despite no Food and Drug Administration approval and no true scientific evidence it would work, some doctors and activist groups aggressively promoted it as a COVID treatment. When the FDA famously tweeted in 2021 “You are not a horse. You are not a cow. Seriously, y’all.” in efforts to discourage its use, many interpreted the message as mocking ordinary patients desperate for help in an uncertain time and the drug went on to become a larger symbol of the distrust between Americans and the government during the pandemic. By 2023, the scientific consensus was that ivermectin did not meaningfully help treat COVID, but personal anecdotes continued to spread.