Could Hantavirus Cause the Next Pandemic? Matthew Pullen, MD, Explains Why the Risk Is Low

As reports of Andes virus infections linked to a cruise ship outbreak have generated concern among travelers and health care professionals, Matthew Pullen, MD, an infectious disease expertsays fears of a hantavirus-driven pandemic are largely unfounded.

During this second installment of an interview with Infection Control Today, Pullen, a member of the ICT editorial advisory board, emphasized that although health care professionals should remain vigilant, the risk of widespread transmission remains extremely low.

When asked whether health care professionals in the Midwest should be concerned about hantavirus infections, Pullen noted that geography remains an important factor.

"Most likely not," he said. "In infectious disease, we always say, 'Never say never.' Just because you haven't seen something doesn't mean it's not around. But especially in the United States, it's very unlikely to see it outside of the Southwest other than someone who's a returning traveler."

Pullen explained that geographically restricted infectious diseases occasionally appear in regions where they are not typically found because patients were exposed while traveling. He cited coccidioidomycosis, commonly known as Valley fever, as another example of an infection primarily found in the Southwest but occasionally diagnosed in Minnesota among travelers returning from Arizona, New Mexico, or California.

Similarly, he said, clinicians should consider hantavirus when evaluating patients with unusual respiratory illnesses and relevant travel histories.

"When you see someone with a compatible pulmonary syndrome that isn't responding to typical therapies and doesn't have positive results on typical tests, you need to start thinking of these more atypical syndromes," Pullen said. "Especially if this person tells you they were on a cruise ship that stopped in Argentina and they have a severe pulmonary syndrome."

Public concern has intensified because hantavirus is often portrayed as a highly lethal disease. However, Pullen said several biological and epidemiological factors make a pandemic scenario unlikely.

"I would say very, very, very low likelihood," he said when asked whether hantavirus could become the next global pandemic.

One reason is that human-to-human transmission of Andes virus remains uncommon and somewhat controversial among researchers.

"It doesn't spread like COVID(-19) does. It doesn't spread like the flu does. It's not that transmissible," Pullen said.

He pointed to estimates suggesting the virus has a reproductive number, or R₀, of approximately 1.2, meaning transmission chains are generally limited and may not sustain widespread community spread.

Pullen also noted that the virus's high mortality rate may actually work against its pandemic potential.

"Diseases that have high case fatality rates, like Ebola, typically will burn out in a population," he said. "They kill so efficiently that they run out of hosts to jump to."

Taken together, limited transmissibility, uncertain person-to-person spread, and a high case fatality rate make hantavirus a serious disease that warrants clinical awareness but is unlikely to become the world's next pandemic threat.