The hantavirus test case

Most public health experts have concluded the virus that killed 3 aboard a Dutch cruise ship poses no general threat. At least one isn't so sure.

Do you know what to think about the hantavirus that struck a Dutch cruise ship last month and now has 18 Americans quarantined in bio-safe facilities in Omaha and Atlanta? I don’t.

Here’s a sampling of the analyses offered by public health experts over the past week about the evolving hantavirus situation:

“Hantavirus is not spread by people without symptoms, transmission requires close contact, and the risk to the American public is very low.” — Jay Bhattacharya, interim Director of the Centers for Disease Control and Prevention, quoted in The Hill

“It’s important to understand this is not Covid. No matter how this virus plays out, its transmissibility is going to be very different than Covid. I don’t see a large, global pandemic coming out of this.” — Dr. Ashish Jha, Senior Fellow at the Harvard Kennedy School and Covid coordinator during the Biden administration, on the PBS NewsHour

“Andes (the name given the hantavirus strain first identified in Argentina) has mitigating characteristics that distinguish it from influenza or SARS-CoV-2, and prolonged, close personal contact is required for transmission. All in all, large-scale outbreaks are now unlikely given the control measures in place.” — Gregg Gonsalves, PhD, associate professor of epidemiology, Yale School of Public Health, writing in The Nation

"There is no chance this will become a pandemic. You have no risk of contracting hantavirus, unless you decide to sweep mice droppings in New Mexico.” — Dr. Vinay Prasad, fired from the Food and Drug Administration, writing on the Sensible Medicine Substack

However, there is at least one cautious dissenter:

“From the moment this latest outbreak hit the news last month, public health officials have been claiming that this virus is spread through ‘prolonged close contact.’ The evidence is not nearly so reassuring… This outbreak is not likely to spark a pandemic, mostly because the hantavirus is less contagious than influenza, measles, and SARS-CoV-2. But given just how little experience we have with this virus, any certainty is hubris.” — Joseph Allen, professor, Harvard School of Public Health writing in The Atlantic

Allen based his conclusions on a “meticulously documented” study of an outbreak in a remote Argentine village in 2018-19, which appeared in the New England Journal of Medicine. The report’s conclusions, written in 2020 by scientists from Argentina, the U.S. military and Centers for Disease Control and Prevention, contradict claims that “prolonged close contact” is required for transmission.

Allen is an expert in indoor air quality. In 2020 he chaired the Lancet’s Covid-19 Safe Work, Safe School, and Safe Travel task force, which modeled the early 2020 outbreak on the Diamond Princess cruise ship that brought Covid to the U.S. The task force was among the first to report that 90% of the spread on the ship was through aerosols, not contaminated surfaces. The CDC didn’t update its guidance until late 2020, long after the disease had spread through the general population.

“I am alarmed to see the same pattern playing out now,” he wrote in the Atlantic this week.

Allen interviewed the physician on board the MV Hondius who treated infected passengers after the ship’s official doctor got sick after coming in close contact with the first patient. But the others who got sick, three of whom died? “They had merely shared space in the dining room and the lecture hall and had not had close contact,” he reported. “We’re now at 10 confirmed cases from the ship, which aligns with the prior outbreak dynamics (as reported in NEJM): one person infecting many, no close contact required.”

I read that NEJM study about the Argentine outbreak yesterday. Here’s a direct quote from its conclusions:

“On the basis of both the epidemiologic and genomic investigations of person-to-person transmission events, it appears that inhalation of droplets or aerosolized virions may have been the routes of infection. … The super-spreading capability of the (Andes) strain shows a facility for sustaining continuous chains of transmission if no control measures are enforced.”

Now, it wouldn’t be fair to say no control measures are being enforced by the current administration in Washington and two agencies primarily responsible for responding to infectious disease outbreaks, the CDC and the National Institutes of Health. They moved quickly to airlift and isolate the exposed Americans.

Photo: University of Nebraska Medicine

Europeans have taken similar precautions. According to EuroNews, 26 Dutch passengers have been quarantined either at home or in facilities; 14 Spanish passengers and 5 from France were airlifted to hospitals in their home countries, with at least one having been confirmed as catching the disease on board the ship. They all face up to seven-week quarantines where they will be continuously monitored with PCR testing.

Why seven weeks? The Andes hantavirus, the only variant known to spread from humans to humans, can take that long to generate the respiratory disease that can prove fatal. The Argentine strain had a reported fatality rate of 30% to 40%, but that number is highly suspect. The dominator in the percentage is based on those who tested positive for the virus. The real rate is unknown because many more people in the remote village may have been exposed yet never developed symptoms and were never tested to see if they carried the virus.

Are we ready?

After my brief review, I came away somewhat concerned about the prospects for a broader hantavirus outbreak but generally agree the prospect of a population-wide pandemic is unlikely. However, thanks to a good summary provided by Gonsalves in his Nation article, here’s the state of U.S. preparedness for the next viral threat that reaches U.S. shores — an inevitability in our warming world:

• The White House eliminated the Office of Pandemic Preparedness and Response Policy;

• The Trump administration closed 10 Centers for Research in Emerging Infectious Diseases that study zoonotic pathogens that jump from animals to humans, like the hantavirus;

• The Trump administration gutted the STOP Spillover Project, a USAID-funded network that tracked “menacing animal viruses across seven countries”;

• The Trump administration paused research on high-risk pathogens at the Integrated Research Facility in Frederick, Maryland;

• The CDC has an acting director without medical experience as does the Division of High-Consequence Pathogens;

• The administration has wound down NIH research on mRNA vaccines, which could be used for a hantavirus vaccine;

• The president’s 2027 proposed budget sharply cuts state and local preparedness grants to health departments and hospitals around the country; and, in a final irony,

• Its DOGE cuts from a year ago eliminated the CDC’s cruise ship inspectors and port health workers.

Bhattacharya, in his public statements, has repeatedly said the U.S. is cooperating fully with international agencies in the current outbreak. Yet the U.S. no longer belongs to the World Health Organization, which, as Gonsalves points out, “leaves us flying solo without a key source of international collaboration and coordinated planning.”

Is the U.S. prepared for the next serious emerging viral threat? I think the answer is obvious.