Pathophysiology of C. diff colitis

This week I will be writing about the pathophysiology of C. diff colitis. Basically, what that means is -- what does the little bugger do to make life so horrible?

Here is a visual with some scientific wording to help you understand if you are a visual learner.

Basically what is happening is the following: 

1. C. diff enters the gut usually through from consumption of fecal matter (which can occur unnoticeably) 
2. Without other gut flora to keep C. diff in check, the bacteria proliferates uncontrollably. As the bacteria grows, toxins are released. Most pathogenic C. diff strains release Toxin A and Toxin B. 
3. Toxin A and Toxin B work to cause inflammation (colitis) and to inflict mucosal damage, respectively. 
4. Destruction of the lining ultimately prevents absorption in the gut, leading to the diarrhea that is commonly seen in patients. Prolonged infection can ultimately lead to sepsis (infection of the blood), which can cause systemic organ failure. 

It is thought that there is a hyper-virulent  strain named NAP/BI/027. This strain is thought to cause more severe symptoms and faster acting, in terms of damaging the colon.

Interestingly, neonates, who are often carriers are the C. diff toxin,are aysmptomatic. It is believed that in addition to acquiring maternal antibodies in utero against the C. diff toxins, the immature gut cells of a neonate may lack the intestinal receptors for the C. diff toxins altogether. This prohibits the toxins from eliciting the immune response that ultimately destroys the mucosal lining of the gut.

Need I remind you? ALWAYS WASH YOUR HANDS! 

References

Lamont, T. J. (2015). Clostridium difficile in adults: epidemiology, microbiology, pathophysiology. Uptodate. Retrieved from  uptodate.com/home

Who is at risk?

Before I begin to bore with you with numbers and facts, here is an image from the CDC discussing some key facts about the spread of C. diff.

According to the CDC the populations at greatest risk for acquiring C. diff are patients with:

• antibiotic exposure
• proton pump inhibitors (usually used for patients with GERD --gastroesophageal reflux disorder) -- this reduces the acidity of the stomach, which is essential for destroying pathogenic bacteria, such as certain strains of  C. diff. 
• gastrointestinal surgery or manipulation
• long length of stay in a healthcare setting (including nursing homes)
• a serious underlying illness
• immunocompromising conditions (eg: transplant patients, HIV patients)
• advanced age (65+)

Based in a 2008 study also published by the CDC the following impact of C. diff was determined: 

• Hospital acquired, hospital onset of C diff: 165,000 cases were reported resulting in $1.3 billion in excess costs and ultimately leading to 9.000 deaths annually 
• Hospital acquire post discharge (up to 4 weeks): 500,000 cases were reported resulting in $0.3 billion in excess costs and leading to 3,000 deaths annually
• Nursing home onset: 263,000 reported cases, $2.2 billion in excess costs and 16,500 deaths annually 

These numbers are astounding! Patients and health care providers need to pay better attention to preventing episodes of C. diff as treatment is difficult. While old age and serious illnesses are not always risk factors that can be altered, limiting antibiotic exposure and preventing C. diff exposure can great reduce transmission! 

Don't forget folks, ALWAYS WASH YOUR HANDS! 

References 
Center for Disease Control and Prevention. (2015). Clostridium difficile infection. Retrieved from: http://www.cdc.gov/HAI/organisms/cdiff/Cdiff_infect.html. 

C. Diff defined

Clostridium difficile, or more commonly known as a C. diff, is one of the 1000 types of bacteria that resides in the human gut. The bacteria in our gut help to keep us healthy by aiding in digestion of our food and preventing bad bacteria from taking over our intestines. People who have other illnesses or a prolonged use of antibiotics can have an altered bacterial composition in the gut. During this time patients can get a C. diff infection, where the otherwise harmless bacteria takes over the gut and grows out of control.  This can cause symptoms of diarrhea, belly pain and tenderness and can ultimately lead to Clostridium difficile colitis and possibly sepsis (blood infection). I will discuss these points in later weeks.

C. diff bacteria that does not require oxygen to survive. It takes two forms -- a vegetative and a spore form. It is a fastidious bacteria in its vegetative state, actively releasing toxins. Outside the gut, it lives in a spore form. In this form, the bacteria is resistant to heat, acid, and antibiotics and can live for a very long time. It may be found on things in the environment such as bed linens, bed rails, bathroom fixtures, and medical equipment.  It is a bacteria that is found in feces. Patients get infected when they touch items or surfaces with contaminated feces and then touch their mouth or mucous membranes. It can also spread from person-to-person on the hands of doctors, nurses, and other healthcare providers and visitors. 

Upon diagnosis of C. diff, patients in hospitals are put into "isolation rooms", although some institutions will isolate patients who are suspected of having C. diff until test results come back negative. Placing patients in isolation rooms ensures that healthcare providers and visitors where gloves and gowns to prevent transmission. Studies have shown that spores may be difficult to remove from hands even with hand washing!

Below is a video with more information about C. diff, although I will provide you more details as the weeks go on.



Also, remember:

ALWAYS WASH YOUR HANDS