Hantavirus Outbreak: Why Experts Say It’s Serious But ‘Not the Next COVID’

The recent hantavirus cases linked to a cruise ship have made headlines, but health experts are delivering a clear message: this is not the start of a new global pandemic like COVID-19. Still, they are urging caution because of the potential number of people who may have been exposed—especially during a flight from St. Helena to Johannesburg where a symptomatic passenger was on board.

“Other people were sitting close to that passenger and if she was as sick as it seems she was … that could spark a pretty serious chain of transmission,” said Jeanne Marrazzo, MD, MPH, the CEO of the Infectious Diseases Society of America (IDSA), during a recent press briefing.

A flight attendant on that same trip who went to the hospital with possible symptoms has since tested negative for hantavirus, offering some relief. But the situation remains under close watch by public health officials worldwide.

What Exactly Is Hantavirus and Why Should You Care?

Hantavirus is a family of viruses spread mainly by rodents, but certain strains—like the Andes virus involved in this outbreak—can spread from person to person. This is rare, but it is what makes the current situation concerning.

For most people, hantavirus is something they will never encounter. However, when outbreaks do occur, the consequences can be severe. The disease can cause hantavirus pulmonary syndrome (HPS), a serious respiratory illness that can be fatal. According to experts cited in the briefing, the case fatality rate for confirmed cases can be as high as 30%. That means roughly one in three people who get sick enough to be diagnosed may not survive.

Dr. James Lawler, MD, MPH, of the University of Nebraska Medical Center’s Global Center for Health Security in Omaha, warned that while the overall risk is low, it is not zero. “I don’t think you want to be the one who encounters the outlier with a disease that has a 30% case fatality rate,” he said.

How Many People Were Exposed?

One of the biggest challenges in this outbreak is tracking everyone who may have been exposed. Dozens of passengers who were potentially exposed to hantavirus on the cruise ship got off at St. Helena on April 24 and traveled back to their home countries, including the United States.

One Swiss national who disembarked has already been hospitalized with symptoms that were confirmed to be caused by the Andes virus strain. This shows that the virus traveled beyond the ship, making international coordination essential for containment.

Experts like Marrazzo say the level of concern should be high, but she added that this is “not going to be a situation where it’s going to start an outbreak everywhere in the world … from probably these little kindling cases.”

Can Hantavirus Spread Like COVID-19?

This is the question many people are asking, and the answer from experts is a reassuring “no.” The Andes virus does not have the same contagiousness or transmissibility as COVID-19 or the flu. It does not spread easily through casual contact or through the air like respiratory viruses do.

Dr. Carlos del Rio, MD, of Emory University in Atlanta, summed it up during the IDSA briefing: “Is this going to become another pandemic? No. Are we learning a lot? Yes.”

Still, there are unknowns. Experts have expressed optimism that the virus is most contagious when a person is showing symptoms. However, Dr. Lawler pointed out that there is still much we do not understand about the virus.

What Scientists Are Still Learning About the Virus

A case report published in the New England Journal of Medicine about a 2018-2019 outbreak of Andes virus in Argentina revealed something troubling. During that outbreak, three “superspreader events” occurred because people who were in the very early stages of their illness were out socializing. This means that even before they felt very sick, they may have been able to spread the virus to others.

Additionally, some studies of household clusters have found that people can have detectable levels of hantavirus in their blood for more than a week before symptoms ever appear. This raises important questions.

“If you have virus in the blood, how do we know that you don’t have virus that you’re secreting from respiratory mucosal surfaces?” Lawler asked. This uncertainty is why public health officials are taking the situation seriously, even if the overall risk to the general public remains low.

Is There a Treatment for Hantavirus?

Currently, there is no specialized treatment or cure for hantavirus. There is no vaccine, no antiviral drug specifically designed to fight it. The only option available is what doctors call “best supportive care.” This means that patients are treated for their symptoms—often with oxygen, fluids, and breathing support in a hospital intensive care unit—while their bodies fight off the infection on their own.

This lack of a targeted treatment is one reason why prevention and early detection are so important. If you think you may have been exposed, seeking medical care immediately is critical.

What About the Virus Mutating?

One piece of good news comes from studying past outbreaks. Marrazzo noted that during the 2018-2019 outbreak in Argentina, there was not a significant number of mutations in the virus over time. “That’s very different from some respiratory viruses … that mutate very rapidly, where we’re looking at different strains constantly,” she said. “Hopefully that won’t happen with this.”

This stability is encouraging because it means the virus is less likely to change into a form that spreads more easily or becomes more dangerous.

What Does This Mean for You?

For the average person, the risk of catching hantavirus remains extremely low. Maria Van Kerkhove, PhD, the World Health Organization’s top pandemic expert, told the Associated Press that the risk to the public is still low. “This is not the next COVID, but it is a serious infectious disease,” she said. “Most people will never be exposed to this.”

Still, the outbreak is a reminder that infectious diseases can emerge in unexpected places. Here are some practical takeaways:

• Stay informed but don’t panic. This is a localized outbreak, not a global pandemic. Public health agencies are monitoring the situation closely.
• Know the symptoms. Early symptoms of hantavirus include fever, muscle aches, fatigue, and dizziness. As the disease progresses, it can cause coughing and shortness of breath.
• If you were on the affected cruise or flight, monitor your health closely and contact a healthcare provider if you develop any symptoms. Be sure to mention your potential exposure.
• Avoid contact with rodents and their droppings in general, as this is the most common way hantavirus spreads.
• Trust expert guidance. The top U.S. official responsible for public health on cruise ships announced he was stepping down, according to STAT, but this does not change the ongoing response efforts.

The Bottom Line

While the hantavirus outbreak linked to the cruise ship is serious and deserves attention, it is not the next COVID-19. The virus does not spread easily, it does not mutate rapidly, and most people will never be exposed to it. However, for the small number of people who are at risk, the consequences can be severe. Public health officials are working to track exposures, provide care, and prevent further spread. As Dr. Lawler put it, the risk is low—but it is not zero. And with a disease that has a 30% fatality rate in confirmed cases, that is enough reason to stay vigilant.

Source: MedPage Today