The medical sleuths of the Centers for Disease Control and Prevention have been thrust into the limelight with the recent Ebola epidemic. Charged with chasing diseases and stopping outbreaks, they’re a geeky bunch of young doctors, veterinarians and scientists, who prefer to work behind the scenes.

I can call them geeks because I was one of them. Like many former disease detectives, I attended the 63rd annual conference of the Epidemic Intelligence Service at the CDC in April. At that time, many disease detectives – or Epidemic Intelligence Service Officers as they’re formally called – had already been deployed to West Africa to help with the outbreak response. But that wasn’t the only epidemic on their list. Closer to home, more familiar pathogens were waging war on humans and the disease detectives had their work cut out.

There were discussions on how to use mobile phone apps like Grinder to track outbreaks of syphilis, and presentations on the recent increase in salmonella outbreaks in the U.S. and how they might be linked to the use of diapers for backyard chickens. There was even a satirical review at the end of the convention – a long-standing tradition - where disease detectives did impressions of public health heroes, past and present, and one young doctor donned a face mask that looked a lot like CDC director Tom Frieden.

Epidemic Intelligence Service (EIS) Officer Dr. Leisha Nolen preparing to depart on assignment to West Africa in response to the 2014 Ebola hemorrhagic fever outbreak across Guinea, northern Liberia, Sierra Leone and Nigeria. Pictured atop the Centers for Disease Control and Prevention (CDC) materiel case to her left are some of the requisite medical supplies she would be taking including phlebotomy vials, and disposable face masks. (Credit: CDC)

The first time I attended the conference as a newly inducted EIS officer in 2011, I couldn’t believe my luck. I was two years out of medical school and overjoyed to be in the company of hundreds of fellow public health fanatics. But I was also terrified since the conference is where current officers present their work to their peers and, even scarier, to eagle-eyed EIS alumni, some of whom served in the EIS as early as the 1960s.

Life as an EIS officer had taken me from hospital doctor in London to what would be a thrilling two years as a disease detective in the U.S. My wardrobe suddenly took a turn for the paramilitary. I wore a stab-proof vest and face-shield while investigating an outbreak of paralysis in an Arizona maximum-security prison (it was Thanksgiving and the inmates were brewing their own hooch which turned out to be laced with botulism). I took a trip to the Grand Canyon in my first month at the service, all in the name of public health, and interviewed homeless people on an American Indian reservation during an outbreak of flesh-eating bacteria. During my first EIS conference, I’d had to present some of this work to the shrewd and discerning audience of expert epidemiologists, but this time around, I could relax.

Ebola might not scare EIS officers, but old-school EIS veterans such as Lyle Conrad, a graduate of the EIS class of 1965, and William Baine, a graduate of the EIS class of 1972, incite terror. These guys are known for approaching the microphone after presentations and identifying every tiny error in the officer’s work in front of the esteemed audience. “Baine eviscerated me,” says Doug Hamilton, recent chief of the EIS and a graduate of the class of 1994, recalling an EIS conference in the 1990s. “Baine asked solid epidemiologic questions but that guy just ripped me apart.”

EIS alumni Dr. Lyle Conrad is honored with the 2014 Stephen B. Thacker EIS Excellence in Mentoring Award for his decades of dedication to applied epidemiology training, mentoring, and building public health capacity. Left to right: Dr. Thacker’s daughter Maria Thacker, Dr. Lyle Conrad, and CDC Director of the Center for Surveillance, Epidemiology, and Laboratory Services Dr. Michael Iademarco. (Credit: Charles Lyon/CDC)

Hamilton refers to Baine and Conrad as the godfathers of epidemiology. They’ve earned that title through a lifelong dedication to public health, including diligent attendance at EIS conferences. “I haven’t missed an EIS conference yet,” says Conrad, who wears a tie with the EIS logo. “But things were different back in 1965. There was only one woman in my class of 30 officers and we had the first African American EIS officer, Bernie Challenor. Bernie got into the EIS but he couldn’t find housing near the CDC.”

Thankfully, things have changed. EIS officers nowadays more closely represent the diverse communities they serve, and nearly 75 percent are women.

One of them, Allison Arwady, gave the first presentation of the week: an outbreak of unexplained fever among inmates at an Illinois prison. Arwady described the twists and turns of the investigation explaining how her first presumption, that a virus was causing illness in 85 inmates, turned out be incorrect. She discovered that a fungal infection, histoplasmosis, was to blame. The answer was in the sky. During the investigation, she noticed thousands of European starlings were roosting in trees in the prison yard and littering the soil below with their droppings. Histoplasma capsulatam thrives in soil contaminated with bird droppings and so Arwady pieced together the puzzle: the recent uprooting of a particularly large tree in the yard had disturbed the soil and likely sent fungal spores flying through the prison yard and into the lungs of inmates.

Prison doesn’t seem a likely landing place for your triple-Ivy league educated primary care doctor (Arwady sports a medical degree from Yale and degrees from Harvard and Columbia) but then you don’t expect your vet to tackle ebola epidemics in Uganda either. Ilana Schafer did just that, and only months into her stint as an EIS officer. Since then, she’s investigated outbreaks of Marburg virus, another cause of hemorrhagic fever, and developed a software tool that helps disease detectives track these outbreaks in the field.

EIS officer Miriam Shiferaw is recognized with the 2014 Paul C. Schnitker International Health Award at this year’s EIS conference for her highly notable contributions in international health, serving the most vulnerable populations in Syria, Sudan and Liberia. Left to right: CDC Epidemic Intelligence Service Acting Chief Diana Bensyl, Miriam Shiferaw, and CDC EIS Program Staff Epidemiologist Doug Hamilton. (Credit: Charles Lyon/CDC)

Since its inception in 1951, more than 3,000 EIS officers have responded to outbreaks around the world. I had no idea when I was in medical school that EIS officers had discovered some of the diseases I was studying. Leigonnaires’ disease, a bacterial respiratory infection, caused an outbreak among attendees of an American Legion convention in Philadelphia and was discovered by Dr. Stephen Thacker on his second day as an EIS officer in 1976. Reye’s syndrome, which causes liver and brain damage in children, was linked to aspirin by EIS officer Dr. Lawrence Schonberger in 1971.

It’s a strange calling to spend years in medical or veterinary school, or writing a PhD thesis, and then decide to use that training to rush to the epicenter of an epidemic. It can be a difficult career choice to explain to your family. My aunt in England couldn’t understand why I wanted to run towards an outbreak when, in her words, anyone in his or her right mind would run away.

Miriam Shiferaw knows what I’m talking about. A pediatrician who worked in the south Bronx before joining the EIS, Shiferaw now contends with her mother’s pleas to stay at home when she’s called to places like Liberia and South Sudan for outbreak investigations. “My mom says no don’t go there, every single time,” says Shiferaw. And perhaps for good reason. After a recent trip to Turkey, Shiferaw spent days in the hospital recovering from an unexplained illness. “I had really bad fevers, headaches. It was awful. I’m pretty sure I had aseptic meningitis,” she says, “but we don’t really know.” At the conference, Shiferaw presented her work investigating outbreaks of hepatitis E virus in South Sudan and the re-emergence of polio in Syria.

For all the threats to your health and safety and for all the explanations and assurances you have to give to mothers and spouses, there is an upside to being an EIS officer. There’s the thrill of chasing mysterious microbes, identifying patient zero in an outbreak and the lifelong friendships that are formed along the way. Acting surgeon general Boris Lushniak, a graduate of the EIS class of 1988 and a moderator at this year’s conference agrees. “I’ve always been convinced that the EIS really is the two most exciting years of one’s life.”