Hantavirus in US? North vs South America — researchers identify three emerging 'hotspots'

The United States (US) has not reported any hantavirus cases linked to the MV Hondius cruise ship outbreak. The country, however, may be witnessing the emergence of new hantavirus hotspots.

As of the end of 2023, the Centers for Disease Control and Prevention (CDC) reported that 890 cases of hantavirus disease had been reported in the US since surveillance began in 1993.

As per the map shared by the CDC, the distribution by state of hantavirus cases in the United States from 1993 through 2023 was as follows:

The majority of hantavirus cases occurred out West, with Colorado and New Mexico reporting 121 and 129 cases, respectively. As many as 92 cases have been reported in Arizona, 79 in California and 61 in Washington.

In contrast, Virginia — one of the hot spots found in Escobar’s research — has reported just two cases, one in 1993 and another in 2021.

A study published in March 2025 in the journal Ecosphere identified Virginia as one of the emerging hotspots of hantavirus in the US. It was followed by Colorado and Texas.

At the state level, researchers collected the largest number of blood sample in Kansas (2014 blood samples), Virginia (1261), and North Dakota (1144).

Virginia exhibited the highest seroprevalence at 7.9% (n = 99 seropositive samples), followed by Colorado at 5.7% (n = 37) and Texas at 4.8% (n = 19), the study showed.

Seroprevalence is the percentage of people in a population who test positive for specific antibodies in their blood. It measures cumulative exposure to a virus or infectious agent—whether from past infections or vaccinations—and is a key tool in public health for tracking disease spread.

"Hantavirus seroprevalence showed an uneven spatial distribution, with the highest seroprevalence found in Virginia (7.8%, 99 seropositive samples), Colorado (5.7%, n = 37), and Texas (4.8%, n = 19)," it stated.

Luis Escobar, an associate professor in Virginia Tech’s fish and wildlife conservation department, was quoted by NBC News as saying, “We see human cases in states like New Mexico, but if you want to capture a rodent that is infected, Virginia emerges as a hot spot."

The study identified 296 seropositive samples across 15 rodent species, including 8 Peromyscus species. It described six new species with hantavirus seropositive samples not previously reported as hantavirus hosts.

Meanwhile, an insight report by Stanford University claimed that hantavirus strains found in North America don’t spread from person to person. Someone may become infected from rodents, but the virus ends there.

The Andes virus, found in South America, is different; it is the only hantavirus documented to occasionally transmit between people. The Andes strain of hantavirus that killed three passengers hasn’t been found in North America.

In 2018, the Andes strain of hantavirus spread throughout a small village in Argentina. Ultimately, the virus infected 34 people and caused 11 deaths.

However rare as it is, hantavirus is not something to take lightly. According to the Stanford report, its fatality rate is much higher than more common viruses such as influenza and COVID-19.

As many as 35 percent of hantavirus cases in the US in recent decades have led to death.

“It clearly affects the lungs,” Jorge Salinas, MD, the medical director of infection prevention at Stanford Health Care, was quoted as saying.

“But it’s not clear how much of that is the virus attacking the lung cells versus the response of our body to the infection," the expert added.

There are no approved vaccines and no specific antiviral therapies proven effective against hantavirus.

Patients who become sick can receive supplemental oxygen; mechanical ventilation; or, in the most severe cases, extracorporeal membrane oxygenation (ECMO), a machine that takes over the work of the heart and lungs while the body fights the infection.

Meanwhile, in a statement on May 15, the WHO said, "As of today, a total of 10 cases, including three deaths, have been reported to WHO, including eight people who were laboratory-confirmed for Andes virus infection and two probable. There have been no further deaths reported since the second of May."

"Because of the long incubation period of up to 6 weeks, more cases may be reported in coming days as passengers return to their countries, where they are being quarantined and tested in specialized facilities or at home," the WHO added.

"This does not mean the outbreak is expanding; it shows that the control measures are working, that laboratory testing is ongoing, and that people are being cared for with support from their governments," the world health body reported.