What Is Clostridium Difficile?

Diarrhea is a common problem in people living with HIV. At times, diarrhea may be a side effect of certain medications used to treat HIV. But, at other times, it is the result of an infection of the gastrointestinal system, with numerous possible agents and causes.

One of the more common causes of diarrhea in people with HIV is a bacteria known as Clostridioides difficile (also referred to as C. difficile.) C. difficile is an organism normally found in the human gastrointestinal tract, accounting for about 3 percent of the bacterial flora in healthy adults.

However, when immune function is compromised, the systems that keep bacterial growth in check can go awry, allowing for C. difficile to increase in population until it can represent anywhere from 10 to 30 percent of the bacterial flora in chronically ill patients. This overgrowth produces toxins that cause both severe infectious diarrhea and inflammation of the large intestine (known as colitis).

Primary symptoms include:

• Watery diarrhea, sometimes with blood or pus
• Fever
• Abdominal pain, cramping, or tenderness

Causes of C. Difficile Diarrhea

In addition to HIV infection, C. difficile-associated diarrhea can be caused by a number of other factors.

• Antibiotic use: When an antibiotic inadvertently kills both "bad" and “good” bacteria in the gastrointestinal tract, overgrowth can occur. In fact, some studies suggest that around 90% of all health-care-associated C. difficile infections are a result of broad-spectrum antibiotic use.
• Anti-ulcer medications: Anti-ulcer medications decrease the acidity of the stomach. In doing so, they can sometimes alter stomach acidity, allowing C. difficile to grow unchecked.
• Long hospital stays: A combination of stress from illness and the potential for patient-to-patient or health-provider-to-patient contamination can increase the likelihood of a C. difficile infection. In fact, C. difficile is the most common cause of hospital-associated diarrhea.
• Older and younger age: People older than 65 years of age are at greater risk, since their immune function tends to be weaker, while younger children and infants can also be subject to infection due to their immature immune response.

How Is C. Difficile Spread?

C. difficile is present in the stool of infected people, forming spores that can lie on toilets, bed rails, towel racks, and so on. However, it is not spread via direct contact between these surfaces and a patient’s skin. Instead, it is spread via fecal-oral transmission—that is, when a patient touches a contaminated surface and then touches his/her mouth, thereby ingesting it.

C. difficile spores can live for up to five months on environmental surfaces. They are not easily killed by traditional disinfectants and often require a 1:10 concentration of chlorine bleach to ensure complete eradication of the spores.

Hand washing is the primary way to prevent the spread of C. difficile from person to person. Surfaces should also be thoroughly cleaned, as well as utensils or personal hygiene items that may have been in contact with ill or hospitalized individuals. Avoid alcohol-based cleansers, since they are less effective in killing C. difficile spores.

How Is a C. Difficile Infection Treated?

Treating a C. difficile infection requires a two-fold approach: treating the symptoms and treating the cause. In some patients, this can prove to be difficult, often require treatment over the course of several months to even a year. The emergence of drug-resistance only complicates the matter further, particularly in patients with severely compromised immune systems.

Therapy can often include:

• Antibiotics such as Flagyl and vancomycin (the latter of which is more effective against drug-resistant strains).
• In cases caused by medication, stopping the antibiotic thought to have caused the infection.
• Oral hydration with water and electrolyte replacement solutions, as well as the intravenous replacement of fluids in severely dehydrated patients.
• Pain-relief medications can be used, but only with caution, because they can sometimes mask abdominal symptoms, thereby delaying diagnosis of an underlying illness. Over-the-counter medications like Tylenol can be used to relieve mild to moderate pain. Narcotics should be used with caution, since they can affect gastric function, while Motrin should be avoided as it can cause further gastrointestinal irritation.

Finally, one of the newer treatments reserved for the most severe cases is the fecal transplant. Is is not commonly used, but involves the process of removing stool from a healthy individual and transplanting into the person with C difficile.

It is considered more of an emerging therapeutic procedure and therefore must be performed by a gastrointestinal specialist experienced in fecal bacteriology.