For Kayla Small and Maggie Marcus, being roommates is truly living dangerously.
The two college-age friends have a rare disease that means sitting side by side in a car, sharing a glass or indulging in a bar-side Generation Y-style kiss could put their lives at risk.
Small and Marcus suffer from cystic fibrosis, a genetic disease that affects about 1 in 2,500 white Americans. Other races can be affected, but the majority of cases are found among those of European descent.
CF is characterized by extremely thick mucus that clogs the lungs and digestive tract, causing respiratory and digestive problems.
The viscous sputum can make breathing difficult, but it's the ideal environment for bacteria of all kinds to thrive and form large antibiotic-resistant colonies.
Healthy people don't get sick when exposed to the bacteria of a person with CF. Trouble starts when bacteria is passed from one CF sufferer to another, and the consequences can be deadly.
CF patients generally start off with comparatively mild infections like staph, but as the disease progresses, the strains that take root become progressively more virulent.
Even with regular checkups, one can never be absolutely sure what kind of bacteria is growing at a given moment, and if a person with a particularly vicious bacteria passes it to someone who doesn't have it yet, he or she can inadvertently quicken the other's decline.
The bacteria of concern to CF patients are easily contracted, so doctors advise patients to keep a minimum safe distance of three feet between each other at all times.
"It's a struggle," said Clement Ren, director of the Cystic Fibrosis Center at the University of Rochester. "You want to provide guidelines that work but are not unreasonable. You can't put everyone in spacesuits."
Yet Small, a published writer and a Columbia University graduate, subscribes to a personal philosophy that values intimacy with others who share her experience above all else -- even if it could mean she will get sicker faster.
Bill Taub, a clinical social worker at Duke University Cystic Fibrosis Center, estimates that about 10 percent of CF patients he has worked with have expressed similar feelings.
"We in the field need to accept that some will make that decision," he said. "A patient once told me he didn't want to feel like a leper. Some people feel they need to ignore the restrictions in service to the quality of their lives. I am very sympathetic with her experience. That doesn't mean I agree with it."
Most of the outlaws are young, somewhere between 13 and 25, by Taub's estimate.
The mean life expectancy for CF patients is 37, but doctors say it is becoming increasingly common for patients to live into their 40s and 50s -- an enormous leap in 50-odd years. When the disease was first identified, children who contracted it rarely made it past the age of 2.
But averages don't mean much when you see your friends die young. A girl Small knew as a teenager died at 24, and a boy she met on the Internet died at 22 waiting for a lung transplant.
She says she broke off contact with him out of fear of witnessing the death of one of her best friends.
She's trying to work through her fear. She's even thinking about going to visit an ex-boyfriend with CF who told her to stay away because he'd contracted cepacia -- the category of bacteria that contains the strain that signals the end of the line for many.