Hantavirus Patients Are in U.S. Quarantine. There's No Approved Test or Treatment for Them.
No widely approved PCR test. No approved treatment. The most advanced antibody therapy was shelved when its funding expired.
Andes hantavirus is now on U.S. soil
Eighteen passengers from a hantavirus-stricken cruise ship arrived in the United States early Sunday morning. One is in a biocontainment unit in Nebraska after a “mildly positive” PCR test. Two more are at Emory University in Atlanta, one of whom is symptomatic. Fifteen more are in quarantine, and about seven others who returned home earlier are being monitored across five states.
The virus is Andes hantavirus, the only hantavirus known to spread person-to-person. Three people have died in the outbreak linked to the MV Hondius, an expedition cruise ship that spent the Antarctic season in the South Atlantic. Cases are now being tracked in more than a dozen countries.
The public health response is real and moving fast. But two basic tools are missing: a way to diagnose the virus quickly and anything to treat it.
Can U.S. hospitals diagnose Andes hantavirus?
There is no widely available approved PCR test for Andes virus available to U.S. hospitals. The CDC’s own interim guidance from May 10th confirms this.
PCR tests detect the virus itself and are most useful early in illness, when a patient first develops a fever and clinicians need an answer fast. Companies sell hantavirus PCR kits, but they are labeled “research use only.” They have not been validated under CLIA, the federal standard that governs lab testing on patient specimens. That means hospital labs cannot run them on patients and act on the results.
What is available are antibody tests, IgM and IgG, offered through the CDC, some state and academic labs, and Quest Diagnostics. But antibody tests detect the immune response, not the virus. They don’t turn positive until later in the illness, after the immune system has had time to react. They don’t help in the early window when it matters most.
A handful of state labs have filled the gap on their own. California’s viral disease lab has a validated hantavirus PCR originally built for Sin Nombre virus that can also detect Andes. Nebraska’s public health lab developed and validated its own assay specifically for this outbreak. These are state-by-state fixes, not a national system.
If a returning passenger in Texas or Florida develops symptoms tomorrow, their specimens would likely need to ship to the CDC or one of these few state labs. That adds transit time at the exact moment when speed counts.
The Andes hantavirus therapy that was defunded
There is also no FDA-approved treatment for Andes hantavirus. No antiviral. No specific therapy. Care is entirely supportive: oxygen, mechanical ventilation, and in the most severe cases, ECMO, a machine that takes over the work of the heart and lungs.
The most advanced therapeutic candidate was a monoclonal antibody developed at Albert Einstein College of Medicine and the U.S. Army Medical Research Institute of Infectious Diseases at Fort Detrick. It protected hamsters against Andes virus in a study published in 2022. But the NIH funding for that program expired in 2024 and was not renewed. The work was shelved.
Moderna announced an early-stage vaccine collaboration with the Army and Korea University in 2024, but it has not been studied in humans and is years from clinical use. Last summer, the Trump administration pulled funding for Moderna’s broader mRNA vaccine contracts as part of a wider decision to defund the entire BARDA mRNA vaccine portfolio.
If a quarantined patient progresses to the severe cardiopulmonary phase of Andes virus infection, there is nothing specific to give them.
What’s left of the U.S. outbreak response system
The biocontainment capacity is also thin. Nebraska’s unit has five rooms, but one is now a lab. Realistic capacity for Andes virus patients: two to three beds. A broader National Special Pathogen System does exist, with regional treatment centers across the country.
Meanwhile, the federal leadership picture is its own constraint. HHS Secretary Kennedy said, “we’re not worried” about the hantavirus outbreak. But that disregards how many Americans are feeling right now. Prior to taking office, Kennedy said that we needed to take a break from infectious diseases, and he’s waging war against the safest, most effective, and most cost-effective tools we have to combat viruses: vaccines. The CDC director position has been vacant for over eight months. Dr. Jay Bhattacharya, the NIH director, is also moonlighting as acting CDC director. He acknowledged on CNN that it’s hard to wear both hats. The FDA commissioner is reportedly being fired. There is no surgeon general. USAID has been effectively dismantled. The U.S. has withdrawn from the World Health Organization. It took until Friday for the CDC to alert clinicians. And they haven’t felt the need to give the American public regular daily briefings.
That’s the real story here: the science is working, but the institutions meant to translate it into public understanding and confidence, and into coordination and getting things done on the ground, have been gutted. Public health is a lot like the military. It’s about the chain of command, operations, and logistics.
Here’s a concrete example of what’s being gutted: South Africa was able to quickly sequence this virus and confirm what strain it was. They could do that because the U.S. had invested in genomic sequencing infrastructure there through PEPFAR, the HIV program. That same program has now been cut.
We’re lucky hantavirus isn’t good at causing pandemics. Next time, we may not be so lucky.