With a fatal hantavirus outbreak setting off public health alarms, could ivermectin be a solution?
As 18 people who were aboard a hantavirus-stricken cruise ship prepared for their May 11 return to the United States, some on social media said the antiparasitic drug ivermectin could be an effective treatment for hantavirus.
Only it’s not. We spoke with four doctors who told us there are no specific drugs or cures for hantavirus, which is spread primarily by rodents. But doctors treat hantavirus patients’ symptoms with supportive care, including providing supplemental oxygen or administering blood pressure medication.
One of the U.S.-based passengers tested positive outside the U.S. but isn’t currently experiencing symptoms; another person is displaying some hantavirus symptoms without a clear cause, health officials said. Most of the 18 people were taken to a quarantine unit at the University of Nebraska Medical Center; two people were moved to a biocontainment unit at Atlanta’s Emory University.
U.S. health officials plan to assess passengers for a few days; they will be monitored for 42 days total, either at home or in one of these medical facilities. Nine other people who’d already disembarked from the MV Hondius or been exposed to a confirmed hantavirus case on an international flight are also being monitored across six states.
American passengers from the cruise ship, MV Hondius that was stricken with hantavirus, arrived in Omaha, Nebraska after flying from Tenerife, Spain, May 11, 2026. (AP)
Q: Is there a treatment for hantavirus infections?
No, there are no specific treatments for hantavirus infections.
There are at least 24 types of hantavirus that cause disease in humans, but most of those cannot be transmitted by humans. The Andes hantavirus linked to the cruise ship outbreak is the only strain known to spread from person to person. It belongs to a group of hantaviruses endemic to the Americas.
Its early symptoms include fever, headache, muscle aches and gastrointestinal symptoms. Andes hantaviruses typically affect the heart and lungs, through a condition called hantavirus cardiopulmonary syndrome. Symptoms progress to include cough, shortness of breath, accumulation of fluid in the lungs and shock.
Some research supports using the antiviral drug ribavirin to treat other types of hantavirus infections that can cause kidney failure, but that’s not the kind found aboard the cruise ship. Ribavirin hasn’t been proven effective for viruses that affect the heart and lungs, Harvard Health reported.
“Some treatments have been studied for different species of hantavirus, but there are no treatments with sufficient evidence to my knowledge at this time,” said Dr. Emily Abdoler, a University of Michigan Medical School clinical medicine professor.
That’s partly because it’s a rare infection.
Annually, there are about 300 hantavirus cases across North and South America, which make it difficult to conduct studies that would establish effective treatments, Abdoler said.
Q: Is there anything doctors can do to help someone with hantavirus?
Yes. We spoke with four physicians who said treatments focus on addressing the complications caused by the illness.
Doctors can’t cure the infection, but they can often support “normal body functions until the immune response controls and then resolves the viral infection,” said Dr. Anna Wald, a University of Washington School of Medicine professor.
During severe hantavirus infections, she said, patients might not be able to maintain normal blood pressure or their lungs might stop delivering oxygen to the body.
“The only treatment we have available is what we call supportive care, such as providing oxygen, monitoring the respiratory status and even intubating the patient if needed,” said Dr. Monica Gandhi, a University of California San Francisco professor of medicine.
If someone’s blood pressure drops — which can happen when shock sets in — Abdoler said doctors might prescribe medications called vasopressors, which constrict blood vessels.
The speed and quality of care people receive will affect their survival, said Dr. Peter Chin-Hong, a University of California San Francisco professor of medicine.
In some cases, patients with severe illness might need advanced life support such as ECMO or extracorporeal membrane oxygenation, which involves pumping blood into a machine outside the body that removes carbon dioxide before sending the newly oxygenated blood back into the person’s body.
Researchers are also investigating experimental therapies including antivirals, convalescent plasma or monoclonal antibodies, Chin-Hong said.
Q: Why can’t ivermectin work as a hantavirus treatment, as some people claimed online?
All four doctors told PolitiFact they knew of no evidence showing that ivermectin would be effective against hantavirus.
“Ivermectin is an excellent medication for parasitic infections but there is no clinical data that it works against viral infections, including hantavirus,” Wald said.
Chin-Hong said some people have theorized that ivermectin could have antiviral uses because it blocks a specific protein that some viruses must bring into the nucleus to reproduce there.
“This is not relevant for hantavirus, which can reproduce in other ways, not involving the nucleus,” such as in a cell’s cytoplasm, he said.
Ivermectin has shown some promising activity in test tubes — not clinical trials — against viruses such as SARS-CoV-2, but not hantaviruses; it hasn’t been studied against hantavirus in any setting, Chin-Hong said.
“I would worry that promoting these messages may lead to false hope and delay access to care,” he said. “In hantavirus, timeliness in receiving care is crucial.”
RELATED: What is hantavirus? What we know about the fatal cruise ship outbreak
This story originally appeared on PolitiFact
