Local physician Dr. Richard Mills is researching a vaccine that could prevent C. diff, a dangerous species of bacteria that often infects hospital patients.

If the vaccine works, it could save a lot of lives, time, and money. C. diff, which typically affects patients who have received antibiotic treatment, causes 14,000 fatalities and $4.8 billion worth of acute healthcare costs in the U.S. alone every year, according to the Centers for Disease Control and Prevention. It can cause diarrhea and, in the worst cases, a life-threatening inflammation of the colon known as toxic megacolon. Some nurses claim they can smell a C. diff infection when they walk into a patient’s room.

“One of the reasons I’m interested in this trial is C. diff is probably the most feared infection we see in the hospital setting,” Mills says. “The MRSA stuff has gotten a lot more press, but in terms of which one is on the rise and causing more problems, it’s probably this one.”

C. diff’s full Latin name is Clostridium difficile. That’s difficile as in difficult. It got its name because it was difficult to grow in a laboratory setting, but it has a double meaning: C. diff infections are also exceedingly hard to treat and prevent.

“It results in people getting sicker, having to stay in the hospital longer, and in some cases people die,” Mills says. “It particularly targets those people who are the sickest.”

Although C. diff has traditionally infected older patients and those receiving long-term hospital care, the Mayo Clinic reports that it is increasingly showing up in younger, healthy patients with no history of antibiotic use. And according to a 2008 study published in the New England Journal of Medicine, mutations in the bacteria are making it more prevalent and virulent. Among people who are successfully treated (with further antibiotics) for a C. diff infection, one in five will experience a recurrence of the infection.

Mills practices at East Cooper Internal Medicine and treats patients at East Cooper Medical Center, Roper Hospital, and Roper St. Francis Mt. Pleasant. For the past 11 years, he has also been conducting medical studies for PMG Research, a company inside a modern brick medical office building in Mt. Pleasant. In this case, PMG has a contract with worldwide vaccine giant Sanofi Pasteur to test an experimental injected vaccine called Cdiffense. Mills is the lead investigator for the Charleston area, which is one of 100 U.S. sites conducting randomized, placebo-controlled studies of the vaccine. Worldwide, Sanofi Pasteur aims to test the vaccine on 15,000 adults in 17 countries.

“If it works as promised, the target would be anyone who’s going into a hospital or nursing home,” Mills says. The vaccine, an injection followed up by two booster shots, would need to be administered well in advance of a hospital stay in order for antibodies to develop. For the purposes of the study, test subjects must fall in one of two categories:

1. Patients who have had at least two 24-hour hospital stays and received systemic antibiotics in the past 12 months

2. Patients who are anticipating an inpatient hospitalization of more than 72 hours within the next 60 days for certain types of surgery*

Sanofi Pasteur isn’t the only company working on a C. diff vaccine, but according to Mills, it is the furthest along. The company launched Phase III of its study in August 2013, and if Phase III proves successful, Mills says the FDA could then take 18 months to two years to grant final approval for the vaccine.

C. diff is everywhere, more or less. It can be found in water, air, soil, and even in the digestive tracts of healthy people with no symptoms. But Mills says it doesn’t typically affect humans unless something has wiped out their gut flora — that is, the naturally occurring spectrum of bacteria and microorganisms found in the digestive tract.

“The usual pattern is someone is very sick, they get on broad-spectrum antibiotics, the antibiotics wipe out the normal flora of the gut, and then [C. diff] overgrows that and produces a toxin,” Mills says.

Currently, hospitals have precautions in place to prevent the spread of C. diff, but efforts at prevention have had mixed results. Hospital staff use contact precautions with infected patients, including wearing gloves and setting up barriers.

Some studies have suggested that probiotics can encourage the regrowth of gut flora and help prevent recurrent infections. Another, less appetizing, option is fecal transplantation, which is pretty much what it sounds like. A stool sample is taken from a healthy person and inserted into the C. diff-infected person, often via an enema or a nasogastric tube.

“That’s always a gross one to talk about. That one, thankfully, I haven’t had to use with any of my patients,” Mills says while knocking on a wooden table.

If Cdiffense proves effective, doctors will have one more weapon in the fight against Clostridium difficile — one that doesn’t involve shooting poop up a person’s butt. Mills says it could be used preventatively before a patient ever comes to the hospital.

“You know you’re going to need elective knee or back surgery, female surgery, whatever you’re going to need,” Mills says, “and you get the vaccine in the month leading up to your surgery.”

* To learn more about the study and find out if you are eligible to participate, visit cdiffense.org or pmg-research.com/studies/facility/mt-pleasant. Some test subjects will receive a placebo, and the study is observer-blind, meaning PMG will not know which patients are receiving a placebo.

CORRECTION: The print edition of this story misstated the first criterion for participants in the study, stating that patients needed to have had at least two 72-hour hospital stays in the past 12 months. The terms of the study were modified after the City Paper went to print, so the online edition has been modified to reflect that change.