Infectious disease doctor April Pettit of Nashville was puzzled.
She had been caring for a man in his fifties who came to her complaining of headache and neck pain that had continued for more than a week. He also had nausea, fatigue, chills and not much of an appetite.
After examining him and taking a history, she ran a battery of blood tests, did a head CT scan and a lumbar puncture to check his spinal fluid. She admitted him to the hospital and started him on antibiotics, which seemed to help him enough to discharge him.
But the patient returned a week later with a worsening headache and low back pain. When Pettit ordered a second lumbar puncture, she asked the lab to test for a rare organism.
Sure enough, the lab results found the cerebrospinal fluid sample was growing Aspergillus fumigatus.
That was the "A-ha" moment.
The man had a meningitis (inflammation of the brain and spinal cord) as suspected, but it was caused not by bacteria or viruses but a fungus.
Because of that lab test and what followed, Pettit, 34, and in practice just four years, is credited with finding the first case of this rare meningitis that snowballed into this fall's nationwide outbreak of fungal meningitis. At the root were contaminated steroid injections from a Massachusetts compounding pharmacy.
Public health officials say those contaminated injections, filled with methylprednisolone acetate or MPA, may have been given to 14,000 people nationwide.
As of November 26, 2012, 510 cases of fungal meningitis--caused by various types of fungus--have been reported by 19 states to the federal Centers for Disease Control and Prevention. The death toll stands at 36.
If not for that lab test order, public health experts say, the toll could have been much worse.
Soon after the discovery, Pettit granted only two interviews, according to press officers at Vanderbilt University, where she is an instructor in medicine.
Now, she's declining further requests.
So a colleague, Dr. William Schaffner, professor and chair of preventive medicine and a professor of medicine at Vanderbilt, offered to fill in the story for Take Part.
Asking the lab to run specific tests on the cerebrospinal fluid sample that aren't typically done, he says, "was part of her casting a wider net."
When the lab called back to confirm that the test she ordered was, indeed, positive, "It is not a result anyone would expect," Schaffner says.
This type of fungal meningitis is so rare, Schaffner says, that he recalls seeing only one case in his 40 years as an infectious disease specialist.
After that startling lab result was given, the reaction among Pettit and other doctors, he says, was: "Could this be a lab error?"
To figure that out, Pettit circled back to the patient and his family, looking for any clues that might explain the lab finding. "She spoke to the family and in effect started all over again to take the medical history," Schaffner says.
"At one point, a family member said, "Well, about two or three weeks ago, he did have that pain inoculation in his lower back.'" At that point, Pettit suspected there had to be a link.
Next, she fired off an email to official at the Tennessee Department of Health, setting into motion their investigation.
"Now, it switches to a public health response," Schaffner says. "The disease detectives go to work."
By this time, similar cases had emerged in the community. So the public health detectives went to a nearby clinic, where most patients had received their injections.
The team quickly determined that the infection control practices there were excellent, Shaffner says.
So they looked further, eventually narrowing down the infection possibilities to the steroid injections.
At this point, the FDA and Centers for Disease Control are called in to help.
They traced all the steroid injections back to a Massachusetts compounding pharmacy.
By early October, the compounding pharmacy voluntarily recalled all products made at their Framingham site.
But the work was not yet over. "Now we have over 1,000 patients [who had gotten the injections]," Schaffner says. In other locations nationwide, the same scenario was beginning to play out.
Symptoms of this type of meningitis can one to four weeks or even longer to appear, according to the CDC. Many patients weren't out of the woods yet. They needed to know so antifungal treatment could be started if needed.
The public health officials dove in, some setting up sleeping cots in their offices to save precious time, Schaffner says.
The conventional method is to send a certified letter, according to Schaffner. But in Tennessee, the public health officials decided to contact people by phone or visit their homes to be sure they knew about the potential problem as soon as possible.
After 15 days in the hospital, the original patient became more and more unresponsive, succumbing to the meningitis. The family elected to withdraw life support, and he died a week later.
Without Pettit following her gut to order just one more test, however, countless other families may have had to deal with that agonizing decision.
Kathleen Doheny is a Los Angeles journalist who writes about health. She doesn't believe in miracle cures, but continues to hope someone will discover a way for joggers to maintain their pace.