A map of 431 hantavirus case reports from 1993 to 2022 used in the analysis from LANL scientists Andrew Bartlow’s and Morgan Gorris’ study. Most of the cases occur in the western half of the U.S. compared to the eastern half. The thick black outlines separate the western and eastern U.S., illustrating the prevalence of the virus in the western part of the country. Courtesy/LANL

Morgan Gorris

By KIRSTEN LASKEY
Los Alamos Daily Post
kirsten@ladailypost.com

During their 2024 study on Hantavirus Pulmonary Syndrome, Los Alamos National Laboratory (LANL) researchers made new connections between the respiratory illness, geography and human environmental impact.

LANL scientists Andrew Bartlow and Morgan Gorris discovered that the number of hantavirus cases are higher in areas that are drier as well as in geographic areas where human development intersects with natural rodent habitats.

Andrew Bartlow

In a LANL press release, Bartlow explained the increased number of cases isn’t because there are more rodents, which carry the illness, but because of humans encroaching on their habitats.

“This is common with diseases that pass from animals to humans,” he said in the press release. “When humans encroach on animals’ natural habitats, the animals’ stress levels increase, resulting in higher viral shedding, which increases the likelihood that humans become infected. We see this all over the world. It’s why it’s so important to establish buffer zones between human development and animal habitats.”

To form these connections and conclusions, Bartlow and Gorris partnered with the Centers for Disease Control and Prevention (CDC) to study the number of confirmed cases of hantavirus in the U.S. from 1993 to 2022, Bartlow told the Los Alamos Daily Post during an interview Nov. 20.

Gorris noted that most of the confirmed cases are in the western part of the U.S. and New Mexico is not immune to hantavirus.

“(There are) quite a few cases in New Mexico and they are especially concentrated in the Four Corners area,” she said.

In their study, Gorris and Bartlow created a map that identifies where people are at risk for contracting hantavirus in the U.S.

The goal is for their findings to be a resource for public health officials and healthcare professionals, Gorris said.

“We really hope these maps can be used by public health officials to help with disease risk communications to certain communities,” she said. “They can help with advising healthcare workers that hantavirus is a risk to their patients and increase disease awareness. We know scientifically that disease awareness among physicians and communities leads to better health outcomes. Ultimately it is about getting treatment fast and effectively. We also hope these maps can be used by other researchers. While our maps show the average risk of hantavirus, (the) risk fluctuates year to year depending on the rodent population. We anticipate more cases with greater rodent populations. Our maps can help other researchers target areas for future studies.”

Bartlow added that the other hope is that it will reinforce the need for smart land-use planning and to be mindful of human’s effects on the environment.

“In terms of limiting human encroachment into wildlife habitat … it’s not a local issue, it is more of a world-wide problem, which is why we need everyone’s involvement … everybody being on board and understanding the risk,” he said. “We need healthy people, healthy animals and healthy environments.  The more people who know that the better.  Hopefully teaching people about this … will improve strategies in the future.”

While no one from the healthcare fields has reached out to them directly, Gorris said this work has been shared with the New Mexico Department of Public Health and the CDC does have access to their findings. She added that they will be presenting their study during the American Geophysical Conference in December. Gorris said the conference is a great example of tying environmental data, land data and socio-economic data.

“So, we’re excited to network there as well,” she said.

There are precautions individuals can take, too, to reduce exposure to hantavirus.

Bartlow said people should sweep out their barns and sheds and trap mice when they can. He also recommends wearing a mask in areas that are known to be frequented by mice and to keep these areas well ventilated.

“Just be cautious around those areas … and clean up and be safe and wear personal protective equipment,” Bartlow said.

Another effective method is to use household cleaners that contain bleach, Gorris said.

Hantavirus, according to the LANL press release, is an acute respiratory illness with a mortality rate of about 35 percent in the U.S. Humans become infected when they inhale the airborne particles of feces and urine of disease-carrying rodents.

Gorris said the strain of the virus commonly found in New Mexico is Sin Nombre. The common culprits of the virus are deer mice, she said.

She explained how she and Bartlow got involved in this study on the virus.

“This was part of the LANL TED (Technology Evaluation and Demonstration) program,” Gorris said. “Andrew and I have used similar methods for other studies on mosquito populations and the Jemez Mountains Salamander and its endemic range. We partnered with the CDC because we saw an opportunity to demonstrate our capability to look at different diseases, so this was a collaborative effort through the TED program with the CDC.”

Bartlow added that animal-borne illnesses are an interest of his.

“We’ve been working on these types of questions for a long time so this was just another question we thought we could apply our methods to,” he said.