In a crowded Santa Rosa shelter, Peggy Walsh Goebel is working to keep infectious diseases from spreading.

“We have everything in the shelter from walking well to elderly with fragile medical conditions…we have families with children. You name it, it’s here,” said Goebel, a nurse who is managing medical care at the facility.

Although some people have left – the shelter housed about 1400 at its most crowded – about 800 people, forced from their homes by the Kincade Fire, remain.

Among them are an unusually high number of older adults from skilled nursing facilities in the area, Goebel explained. Elderly people – along with very young children – are at greater risk from infectious disease.

Goebel is aware, and on top, of the risk. She’s ordered 20 portable soap and water stations for the shelter. Hand sanitizer is everywhere. Anyone showing signs of illness is kept separate from the general population.

As California’s current rash of wildfires collides with the onset of flu season, the risk of transmission in shelters – and the possibility of more severe, longer-lived infection – becomes an unfortunate reality. As Goebel puts it, “’tis the season.”

California’s Department of Public Health has requested Tamiflu, an antiviral medication, from Direct Relief, with the goal of preventing a fire-fueled outbreak. Direct Relief also provided personal hygiene kits to shelters housing evacuees.

The state’s infamous blazes, buoyed by fall’s Santa Ana winds, have always overlapped with flu season. But as California’s wildfires grow increasingly frequent and severe, displacing more and more people, the sometimes harsh realities of this common disease may grow harsher still.

Faster spread, slower recovery

Because the flu is so common, it’s easy to conflate it with less-severe colds. But that would be a grave error, according to Dr. Arthur Reingold, a professor of epidemiology at UC Berkeley’s School of Public Health. “It’s a mistake to talk about them in the same breath,” he said. “Influenza infection is really deleterious to the body.”

It’s well documented that people who are crowded together – as in a shelter – are more likely to spread respiratory and other infectious diseases.

“In any environment where you have a lot of people packed together in close proximity, possibly with decreased access to sanitation, or at least to sanitation of services,” viruses have more opportunity to spread, said Dr. Nathaniel Hupert, a professor of healthcare policy and research at Weill Cornell Medical College and co-director of the Cornell Institute for Disease and Disaster Preparedness.

But wildfires may complicate the transmission of flu in other, less expected ways.

For one thing, Dr. Hupert said, the increase in hospitalizations that generally takes place during a wildfire means that hospitals may have a diminished capacity for dealing with flu patients at precisely the moment they most need care. For young children, and even more for frail older patients, that diminished capacity could be devastating.

“The people who end up the sickest, the ones who end up in the hospital, the ones who die, are elderly people and young children,” Dr. Reingold said.

There’s also the likely possibility that “those who have increased susceptibility in normal times to influenza and other respiratory viruses might have that susceptibility even further heightened” by particulates and toxins in the air, Dr. Hupert said.

And for people who come down with the flu, those same particulates and toxins could slow the recovery process, Dr. Hupert explained. “Treatment…might be complicated or prolonged or both by the presence of contaminated air.”

In other words, the fire itself may make people more likely to get sick. Once they’re sick, it may be harder for them to get better.

The future of fires

“Anything that compromises your immune system means you’re less likely to deal with flu,” Dr. Reingold said. The risk of a more severe flu seems to be higher with patients who have diabetes or cardiovascular and pulmonary disease, he explained. It’s also higher for pregnant patients.

But there’s a larger issue, Dr. Hupert said: “We’re into a new normal, which is fires with hurricane-force winds.”

As wildfires grow worse – stronger, faster, larger – we’ll need more resources to deal with precisely these kinds of health issues.

Whether it’s containing an outbreak of flu or increasing access to primary care, according to Dr. Hupert, “all of that’s going to have to change to take into account the new respiratory environment in which we live.”