Sarah Hackbarth knows this much is certain: On July 30, she was injected with one of the contaminated steroids that have killed 33 people.

Since then, she has suffered many of the symptoms that she was warned about: headaches, nausea, numbness.

But one thing she doesn't have is a diagnosis.

Hackbarth, a 24-year-old newlywed from Shakopee, is one of hundreds -- if not thousands -- of people trapped in the gray zone of the national meningitis outbreak.

Months after receiving the contaminated injections, they're still trying to find out if they were infected by a potentially deadly fungus. Many, like Hackbarth, have tested negative for meningitis, yet are struggling with a cascade of unexplained symptoms. And in the absence of hard answers, they fear the worst.

For patients such as Hackbarth, who were living with pain before this happened, it has turned into an endless ordeal. "Any headache that you have, any mild fever that you have ... it terrifies you," she said. "Nobody can give me a straight answer."

Even the experts admit that they've been baffled by the unfolding outbreak. Just last week, Minnesota reported its 13th confirmed case tied to the steroids -- in a young woman who tested negative for meningitis. When doctors discovered that she had a bone infection instead, it was a reminder of what an elusive culprit they've been chasing.

"This is all new to us," said Dr. Tom Chiller, a fungal disease expert with the U.S. Centers for Disease Control and Prevention. "Unfortunately, we're still learning as we go."

'A nightmare'

Hackbarth and her husband, Jake, were on their honeymoon when they learned that she might be in danger. They had gotten married on Sept. 29 and had left for the North Shore of Lake Superior -- oblivious to news reports about the emerging outbreak of meningitis, a dangerous inflammation of the brain or spinal cord, and its link to steroids from a Massachusetts production facility, the New England Compounding Center (NECC).

In early October, the state Department of Health started tracking down nearly 1,000 Minnesota patients who had received the suspect steroid injections at two Twin Cities clinics. Hackbarth was on their list.

She received two steroid shots, records show, from NECC -- one in May and one in July. The second one came from a contaminated lot that was making people sick all over the country.

"It was just kind of a nightmare," she said.

The caller from the Health Department who broke the news asked if she had any suspicious symptoms, such as headache and nausea, that could be a sign of meningitis.

"I answered yes to most of those questions," Hackbarth said, but noted that some of them were not that unusual. Pain, in various forms, has been her constant companion. That's why she was getting the steroid shots, she said; to treat the pain from injuries she suffered from a sexual assault years ago.

But the headaches and nausea persisted, as did a strange numbing sensation. After she returned from her honeymoon, she had a spinal tap to test for meningitis. The test was negative, but she learned that the lab results were slightly abnormal and would be sent for further testing. All she could do was wait.

False alarms?

From the start, health officials say, one of the challenges has been sorting out the danger signs from false alarms, particularly in this group of patients. Many started out with chronic health problems, and the lines between old and new symptoms may blur.

"Headache is really common, especially [for] people in chronic pain," said Dr. David Boulware, a specialist in fungal meningitis at the University of Minnesota. At the same time, he said, news reports about the outbreak probably have fed their anxiety, which "can make a lot of those symptoms worse."

Most of the people exposed to the contaminated steroids were probably able to fight off the fungus naturally, Boulware said.

"There's mold and fungus everywhere in the environment," he noted, and it rarely causes illness. "On a windy day, you might inhale some of this and nothing happens."

The official tally of the meningitis outbreak would seem to bear that out. An estimated 14,000 Americans received the tainted steroids; fewer than 500 cases of illness have been confirmed.

But among patients, the frustration has spilled onto Facebook sites devoted to the meningitis outbreak. "All these people getting tested and coming back negative, and all have had the shots ... Umm, what's wrong with us then?" wrote a woman from Pennsylvania.

Another woman, from California, replied: "I started crying when I read your messages, cause I have been sick w/negative spinal tap and everyone thinks I am crazy!"

Paul Feyereisen, a 48-year-old construction worker from Crystal, says he got contaminated injections in September, and since then, he's run up $11,000 in medical bills in a futile effort to stop his headaches, nausea and vomiting. The medical tests found nothing wrong, said Feyereisen, who is self-employed. "But I'm turning away work because I don't feel good," he said.

Rosalinda Edwards, a 41-year-old single mom from Shakopee, said she started complaining of headaches and eye pain even before she learned that the steroids she got in July were contaminated. But her meningitis test also was negative. "People think, 'Oh you're negative for meningitis, so you're good,'" she said. "You can't see any of the pain or suffering or stress."

Her lawyer, Elliot Olsen, says he represents some two dozen steroid patients in similar situations. "A lot of them seem to be still convinced that they've got something going on," he said. "I think a lot of them will never get an answer."

In limbo for a while

For now, health officials say those in the gray area may remain there for weeks to come. "I wish we could tell people 'you were evaluated, things look good, you can relax,'" said Dr. Ruth Lynfield, the Minnesota state epidemiologist. "We can't."

She said they need to be on the alert for worsening symptoms, and to get them checked out.

"We're obviously not out of the woods," said Chiller, of the CDC.

Back home in Shakopee, Hackbarth says she's trying not to let the uncertainty consume her, and draws strength from her husband, family and support groups.

"I try to keep everything in perspective," she said. "I know in comparison with what other people have suffered, it's not much." Still, she says, "I've really been through a lot the last couple of years. I'm trying to stay positive. But I'm scared."

Maura Lerner • 612-673-7384