The new superbug

[PHP Nepal Vol 3 Issue 1 Jan 2013] | “What exactly is this Clostridium difficile (C. difficile)?” Given the amount of media sensation this super-bug has created, it is not surprising that as an Internal Medicine specialist, I get asked this question a lot.  With all justified press coverage this topic is getting, this is a reasonable and, in fact, a very important question to ask. To take a step back, there are several billion bacteria that reside in our colons, called gastrointestinal “microbiome”. These bacteria talk to each other and to our colon and our immune system in very complicated ways to create a mutually dependent relationship.

This allows every party, consisting of you, your colon, your microbiome, to exist in a happy balance.  This healthy interaction prevents overtake of our guts by disease-causing bacteria, a concept known as “colonization resistance”. Taking certain antibiotics, like clindamycin, ciprofloxacin etc, kills off good bacterial species and decrease the diversity of our microbiome. All this means that small amounts of bad bacteria, which were being suppressed and were waiting in the sidelines for their moment in the limelight, get their chance. Colonization resistance fails and these species take over. 

C. difficile, a kind of bacteria, is one such opportunist. Its spores are everywhere and we come across them in hospitals, clinics and other health care facilities. Lack of hand-washing hygiene is one of the most important ways in which spores of C. difficile spread. Those of us with a disturbed gut microbiome fall prey to the infection. The usual suspects are hospitalized patients, nursing home residents, the elderly and those with recent exposure to antibiotics, though increasingly frequent occurrence of this infection in people with no contact with the healthcare system (so called “community-dwellers") is getting concerning. The incidence of C. difficile infections has increased alarmingly across the globe, especially in Western countries with half a million cases being reported annually in USA itself. Billions are being spent every year in controlling, diagnosing, treating and preventing this infection and this problem has taken on a public health scale. 

It is not a happy experience to come across C. difficile. Once it infects the colon, it can cause anywhere from mild to extremely severe, even life-threatening disease. Pain in the belly, bloating, cramps, and diarrhea are some of the milder manifestations. Severe dilation of the colon requiring emergency surgery, very high fever, and even death can occur.  Treatment mostly consists, believe it or not, of antibiotics! Metronidazole and vancomycin are two of the most commonly used treatments. Unfortunately, even if treated, C. difficile infection can recur in anywhere from 20 to 66% patients after initial infection. This trend of severe infection that relapses makes this bacterium very costly to Governments and healthcare systems globally. New drugs and even vaccines are being developed in a bid to find some way to stop this tide. There is tremendous interest is figuring out low-cost, non-traditional ways to treat this infection.

One such unorthodox method, also getting lots of media attention presently, is stool transplantation. Transplanting a very small amount of stool from a healthy donor to a recipient, a person with several bouts of C. difficile infection usually via a routine colonoscopy, although esthetically challenging, has seemed to work wonders. In fact, within weeks the gut microbiome of the recipient starts resembling the donor. With about 30 years of experience in stool transplantation procedure, called Fecal Bacteriotherapy (FBT) and Intestinal Microbiota Transplantation (IMT), the results have been astounding with an almost 90% total cure rate for cases of recurrent C. difficile colitis. However, the studies from which these data are gleaned have been case-series and, as of yet, randomized data is not available to substantiate the results. Several questions remain before this treatment can become standard of care for recurrent C. difficile infection. Who is the ideal donor, potential for transmitting diseases via FBT, pre-screening for donors, role of FBT in initial C. difficile infection episode etc., are some of those questions. With more and more research into the field of gastrointestinal microbiome using high throughput, non-culture, and molecular-based methods the day might not be far when the questions above can be answered and we can be well on our way of finding a cure for this menace. In the meantime though, wash your hands vigorously with soap and water every time you are around patients in hospitals and clinics – we have not found the magic bullet yet!

Itishree Trivedi, M.D., Department of Internal Medicine, University of Michigan

Milanchowk, Hemja, Pokhara-Lekhnath Metropolitan City - 25, Kaski 33700, Nepal    +977-61400323