The flu descended on Connie Gabaldon like a fog, she recalled, clouding her mind and compromising her judgment. It progressed to chest and back pain, the aches perhaps made worse by a fall the 66-year-old had while riding the bus in Santa Fe, N.M.
Gabaldon is homeless. When she went to the emergency room in late January, doctors told her she also had pneumonia, a sinus infection and the flu.
For the general population, the flu represents a serious health concern. But for the homeless -- who deal with higher rates of chronic illness, fewer resources and crowded conditions in shelters -- catching the flu can be a matter of life or death.
This year, the nation has experienced a vicious flu season on track to break recent records, according to the Centers for Disease Control and Prevention. Although the outbreak has shown signs of decline over the past two weeks, it is ongoing in 45 states and the District of Columbia, thousands of people have been hospitalized, and 114 children have died.
If you're homeless, having the flu "might mean that you can't get up and manage to stay warm. You can't go get food. And if you have a substance abuse disorder and you need to maintain either alcohol or opioid use, then you go into withdrawal," said Eowyn Rieke, a board member of the National Health Care for the Homeless Council.
"The gravity of the flu for people who are homeless is enormous. And I think we often underestimate that."
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Avoiding the flu is just one of many health challenges for those who are homeless. Homelessness worsens depression and cognitive function, said Dr. Margot Kushel, a professor of medicine at the Zuckerberg San Francisco General Hospital and Trauma Center.
Homeless people also have a harder time managing chronic diseases. Roughly two-thirds of the group cope with a chronic condition or a substance abuse disorder. Smoking is common. And 3 in 10 people who are chronically homeless have a serious mental illness, according to the Office of National Drug Control Policy.
William Coleman, a 51-year-old former construction worker who has struggled with cocaine addiction problems, is in counseling and anger management classes at Central Union Mission in Washington, D.C. He is also accessing more preventive health care -- including the flu vaccine, which he got earlier this year.
"I really want to take care of my health," he said, the pungent smell of bleach rising from the bucket and mop beside him, which he uses to clean the sleeping quarters. "I want to live as long as possible."