Health
What to Know About Hantavirus — Local Risk, Response and Readiness
With headlines swirling about a cruise ship outbreak, many around the world have a new concern that’s front of mind — the hantavirus.
As of May 13, the World Health Organization reported eight confirmed cases related to the MV Hondius cruise ship, along with one inconclusive and two probable cases. So far, three patients have died.
Meanwhile, public health officials in Illinois reported a possible hantavirus case in Winnebago County that is unrelated to the cruise ship outbreak. If confirmed, that case would be just the seventh in the state since 1993.
Although rare, hantavirus can cause serious health complications. This has many wondering about the risk Illinoisans face, the response efforts and how we can prepare for emerging diseases.
Hantavirus Across Hemispheres
Hantavirus is not necessarily a new disease, with the Centers for Disease Control and Prevention reporting 890 cases between 1993 and 2023.
Hantavirus typically spreads from animals to humans through rodent feces and urine. In certain places, like abandoned cabins, enough can build up that the virus becomes aerosolized and humans can inhale it.
But the cruise ship outbreak is different from previous cases in North America.
Passengers on the ship, which embarked from Argentina in early April, carry a type of hantavirus known as Andes virus.
“The Andes virus … is a completely different virus, and can transmit person to person,” said Dr. Robert Murphy, a professor of infectious diseases and executive director of the Havey Institute for Global Health at Northwestern University Feinberg School of Medicine.
A 2018 outbreak of Andes virus in Argentina infected at least 34 people, leading to 11 deaths. One analysis of that outbreak found there may have been person-to-person spread of the virus, first at a birthday party and later at a funeral.
Luckily, the type of hantavirus common in North America — the Sin Nombre virus — is not known to spread from person to person.
And despite Chicago’s reputation as one of the “rattiest” cities in America, there’s still a relatively low risk for hantavirus exposure here.
According to Dr. William Sander, a professor of preventive medicine and public health at the University of Illinois, the deer mouse species that typically carries the Sin Nombre virus is not as common in Illinois. The virus is found more often in dry, arid environments like the American Southwest.
Still, the case in Winnebago County near Rockford points to the possibility of contracting the virus outside of the rural, western areas it is most strongly associated with.
Additionally, the relationship between hantavirus and rodents points to bigger health issues that pop up where humans and wildlife meet.
“We’re always concerned about new, emerging diseases,” Sander said. “We had a prime example with COVID-19, where it made that jump (from wildlife) and went human to human.”
Birds, bats and ticks are also common local carriers of diseases. With humans encroaching on nature more and more, Sander recommended treating wildlife with caution.
Is This COVID-19 All Over Again?
Dr. Katrine Wallace, an epidemiologist at the University of Illinois Chicago, made it clear that despite similarities to the early days of the COVID-19 pandemic, today’s outbreak is not the same.
For one, Wallace said, the hantavirus does not spread as easily. SARS-CoV-2 replicates well in the upper respiratory tract and can be spread by talking, laughing and breathing.
Andes virus, on the other hand, targets blood vessels deep in the lungs. According to Wallace, a patient who is coughing the virus up will likely already be showing symptoms of pneumonia.
However, Wallace did find one striking similarity between this outbreak and the COVID-19 pandemic — the spread of misinformation. From hoax claims to unproven ivermectin treatments, she has seen many of the same rumors spread about hantavirus.
“This ecosystem exists, and we can just plug it in to whatever health threat is going on,” Wallace said. “... It’s all stuff that was just recycled from COVID.”
As far as what trajectory the outbreak might take, Wallace said more cases are possible. The virus can take up to 40 days to incubate, so people on the ship are not in the clear yet.
Murphy raised concerns about the role the United States might, or might not, play in the global response.
The U.S. pulled out of WHO earlier this year, cutting off avenues of information sharing. Plus, Murphy said, the U.S. has a lack of leadership at its major health institutions.
“The director of the CDC … is not trained in infectious diseases,” Murphy said. “Typically it’s the feds leading everything, but now it’s the states.”
