What is C. diff?

C. diff is a bacterium that can cause diarrhea and more serious intestinal conditions such as colitis. You may see it called other names - Clostridioides difficile (the new name), Clostridium difficile (an older name), and C. difficile. It causes close to half a million illnesses each year.

What causes C. diff infections?

C. diff bacteria are commonly found in the environment, but people usually only get C. diff infections when they are taking antibiotics. That's because antibiotics not only wipe out bad germs, they also kill the good germs that protect your body against infections. The effect of antibiotics can last as long as several months. If you come in contact with C. diff germs during this time, you can get sick. You are more likely to get a C. diff infection if you take antibiotics for more than a week.

C. diff spreads when people touch food, surfaces, or objects that are contaminated with feces (poop) from a person who has C. diff.

Who is at risk for C. diff infections?

You are at more likely to get a C. diff infection if you

• Are taking antibiotics
• Are 65 or older
• Recently stayed in a hospital or nursing home
• Have a weakened immune system
• Have had a previous infection with C. diff or were exposed to it

What are the symptoms of C. diff infections?

The symptoms of C. diff infections include

• Diarrhea (loose, watery stools) or frequent bowel movements for several days
• Fever
• Stomach tenderness or pain
• Loss of appetite
• Nausea

Severe diarrhea causes you to lose a lot of fluids. This can put you at risk for dehydration.

How are C. diff infections diagnosed?

If you have been taking antibiotics recently and have symptoms of a C. diff infection, you should see your health care provider. Your provider will ask about your symptoms and do a lab test of your stool. In some cases, you might also need an imaging test to check for complications.

What are the treatments for C. diff infections?

Certain antibiotics can treat C. diff infections. If you were already taking a different antibiotic when you got C. diff, you provider may ask you to stop taking that one.

If you have a severe case, you may need to stay in the hospital. If you have very severe pain or serious complications, you may need surgery to remove the diseased part of your colon.

About 1 in 5 people who have had a C. diff infection will get it again. It could be that your original infection came back or that you have new infection. Contact your health care provider if your symptoms come back.

Can C. diff infections be prevented?

There are steps you can take to try to prevent getting or spreading C. diff:

• Wash your hands with soap and water after you use the bathroom and before you eat
• If you have diarrhea, clean the bathroom that you used before anyone else uses it. Use bleach mixed with water or another disinfectant to clean the toilet seat, handle, and lid.

Health care providers can also help prevent C. diff infections by taking infection control precautions and improving how they prescribe antibiotics.

C. diff (also known as Clostridioides difficile or C. difficile) is a germ (bacterium) that causes severe diarrhea and colitis (an inflammation of the colon).

It’s estimated to cause almost half a million infections in the United States each year.

About 1 in 6 patients who get C. diff will get it again in the subsequent 2-8 weeks.

One in 11 people over age 65 diagnosed with a healthcare-associated C. diff infection die within one month.

Risk Factors for C. diff

C. diff can affect anyone. Most cases of C. diff occur when you’ve been taking antibiotics or not long after you’ve finished taking antibiotics.

There are other risk factors:

• Being 65 or older
• Recent stay at a hospital or nursing home
• A weakened immune system, such as people with HIV/AIDS, cancer, or organ transplant patients taking immunosuppressive drugs
• Previous infection with C. diff or known exposure to the germs

IsC. diffcontagious?

Yes. To keep from spreading C. diff to to others:

• Wash hands with soap and water every time you use the bathroom and always before you eat.
• Try to use a separate bathroom if you have diarrhea.
• Take showers and wash with soap.

Can I get C. diff again?

Some people get C. diff over and over again.

• One in 6 people who’ve had C. diff will get it again in the subsequent 2-8 weeks.
• If you start having symptoms again, seek medical care.
• For those with repeat infections, innovative treatments, including fecal microbiota transplants, have shown promising results

Clostridium difficile is a gram-positive rod that can be a commensal bacterium as part of the normal microbiota of healthy individuals. When the normal microbiota is disrupted by long-term antibiotic use, it can allow the overgrowth of this bacterium, resulting in antibiotic-associated diarrhea caused by C. difficile. Antibiotic-associated diarrhea can also be considered a nosocomial disease. Patients at the greatest risk of C. difficile infection are those who are immunocompromised, have been in health-care settings for extended periods, are older, have recently taken antibiotics, have had gastrointestinal procedures done, or use proton pump inhibitors, which reduce stomach acidity and allow proliferation of C. difficile. Because this species can form endospores, it can survive for extended periods of time in the environment under harsh conditions and is a considerable concern in health-care settings.

This bacterium produces two toxins, Clostridium difficile toxin A (TcdA) and Clostridium difficile toxin B (TcdB). These toxins inactivate small GTP-binding proteins, resulting in actin condensation and cell rounding, followed by cell death. Infections begin with focal necrosis, then ulceration with exudate, and can progress to pseudomembranous colitis, which involves inflammation of the colon and the development of a pseudomembrane of fibrin containing dead epithelial cells and leukocytes (Figure). Watery diarrhea, dehydration, fever, loss of appetite, and abdominal pain can result. Perforation of the colon can occur, leading to septicemia, shock, and death. C. difficile is also associated with necrotizing enterocolitis in premature babies and neutropenic enterocolitisassociated with cancer therapies.

Clostridium difficile is able to colonize the mucous membrane of the colon when the normal microbiota is disrupted. The toxins TcdA and TcdB trigger an immune response, with neutrophils and monocytes migrating from the bloodstream to the site of infection. Over time, inflammation and dead cells contribute to the development of a pseudomembrane. (credit micrograph: modification of work by Janice Carr, Centers for Disease Control and Prevention)

Diagnosis is made by considering the patient history (such as exposure to antibiotics), clinical presentation, imaging, endoscopy, lab tests, and other available data. Detecting the toxin in stool samples is used to confirm diagnosis. Although culture is preferred, it is rarely practical in clinical practice because the bacterium is an obligate anaerobe. Nucleic acid amplification tests, including PCR, are considered preferable to ELISA testing for molecular analysis.

The first step of conventional treatment is to stop antibiotic use, and then to provide supportive therapy with electrolyte replacement and fluids. Metronidazole is the preferred treatment if the C. difficile diagnosis has been confirmed. Vancomycin can also be used, but it should be reserved for patients for whom metronidazole was ineffective or who meet other criteria (e.g., under 10 years of age, pregnant, or allergic to metronidazole).

A newer approach to treatment, known as a fecal transplant, focuses on restoring the microbiota of the gut in order to combat the infection. In this procedure, a healthy individual donates a stool sample, which is mixed with saline and transplanted to the recipient via colonoscopy, endoscopy, sigmoidoscopy, or enema. It has been reported that this procedure has greater than 90% success in resolving C. difficile infections.

C. diff bacteria is commonly found in the environment, but most cases of C. diff occur while you’re taking antibiotics or not long after you’ve finished taking antibiotics. People on antibiotics are 7 to 10 times more likely to get C. diff while on the drugs and during the month after.

That’s because antibiotics that fight bacterial infections by killing bad germs can also get rid of the good germs that protect the body against harmful infections, like C. diff infection. If you take antibiotics for more than a week, you could be even more at risk.

Other C. diff risk factors include:

• older age (65 and older)
• recent stay at a hospital or nursing home
• a weakened immune system, such as people with HIV/AIDS, cancer, or organ transplant patients taking immunosuppressive drugs
• previous infection with C. diff or known exposure to the germs

You can still get C. diff even if you have none of these risk factors.

What is the microbiome?

The microbiome is the neighborhood of good and bad germs that live in or on your body—including your stomach and intestines, your mouth, and your urinary tract—and on your skin.

Some of those germs can cause illness, but others are very important in keeping you healthy. A healthy microbiome helps protect you from infection, but antibiotics disrupt your microbiome, wiping out both the good and the bad bacteria.

What are the complications of C. diff?

Common complications of C. diff

Dehydration

Inflammation of the colon, known as colitis

Severe diarrhea

Rare complications of C. diff

Serious intestinal condition, such as toxic megacolon

Sepsis, the body’s extreme response to an infection

Death

Is C. diff contagious?

Yes, but most healthy adults who come in contact with C. diff won’t get sick. They won’t pick up the germs or be affected by them at all.

What is colonization?

Sometimes when healthy people come into contact with C. diff, they will begin to carry C. diff germs in or on their body, but they won’t get sick.

In medical terms, they are said to be “colonized” with C. diff. This is also sometimes called “C. diff carriage,” and a person might be said to be a “C. diff carrier.”

Someone who is colonized has NO signs or symptoms.

Colonization is more common than C. diff infection and does not require treatment. Once your body is colonized, you can remain colonized for several months.

If you are colonized with C. diff, you can spread the infection to others.

Some reasons you might become colonized are:

• You’ve recently recovered from C. diff.
• You have a history of taking antibiotics.
• You’ve recently been hospitalized.

Once your body is colonized with C. diff, you can remain colonized for several months. Colonization is more common than C. diff infection and does not require treatment.

Because it’s possible to spread C. diff to others while you’re colonized, it’s important to always practice good hand hygiene, making sure to wash your hands well with soap and water every time you use the bathroom and always before you eat.

Can I get C. diff in the hospital?

Yes. C. diff is more common in healthcare settings, such as hospitals and nursing homes. This is because many people colonized with C. diff are staying or being treated there.

Symptoms might develop within a few days after you begin taking antibiotics.

• Severe diarrhea
• Fever
• Stomach tenderness or pain
• Loss of appetite
• Nausea

What if I have symptoms?

If you have been taking antibiotics recently and have symptoms of C. diff, you should see a healthcare professional.

• Developing diarrhea is fairly common while on, or after taking, antibiotics, but in only a few cases will that diarrhea be caused by C. diff. If your diarrhea is severe, do not delay getting medical care.
• Your healthcare professional will review your symptoms and order a lab test of a stool (poop) sample.
• If the test is positive, you’ll take a specific antibiotic (e.g. vancomycin or fidaxomicin) for at least 10 days. If you were already taking an antibiotic for another infection, your healthcare professional might ask you to stop taking it if they think it’s safe to do so.
• Your healthcare team might decide to admit you to the hospital, in which case they will use certain precautions, such as wearing gowns and gloves, to prevent the spread of C. diff to themselves and to other patients.

Understanding Your Condition

What is a C. difficile infection?

A C. difficile infection (CDI) results from a type of bacteria (or germ) called Clostridium difficile infecting your large intestine. C. difficile bacteria are common and can be found everywhere. These bacteria can be found in the air, in water, or on items such as door knobs, sinks, and countertops. Small amounts of C. difficile bacteria are even found in many people's intestines.

If C. difficile bacteria in your intestines grow out of control, they can cause an infection. This can happen after a person takes antibiotics. Antibiotics are a type of medicine that fight infections caused by bacteria. When you take antibiotics, the normal bacteria in your intestines that help keep you healthy can also be killed. When this happens, bacteria such as C. difficile can grow out of control. When a person has CDI, chemicals called toxins produced by the C. difficile bacteria make him or her sick.

CDI affects about 500,000 people in the United States each year. CDI can be mild to severe. The most common symptoms of CDI include watery diarrhea (three or more times a day for 2 or more days) and cramping in your belly. Some people with CDI can become very sick. In rare cases, severe CDI can be life threatening.

Symptoms of severe CDI may include:

• Having watery diarrhea often (as many as 15 times) throughout the day and night
• Cramping and pain in your belly that may be severe
• Blood or pus (a thick, yellowish substance) in your bowel movements
• Tenderness in your belly
• A swollen belly
• A fever
• Nausea
• Vomiting
• Not enough water in your body (called "dehydration")
• Loss of appetite
• Weight loss

What increases the risk of CDI?

Anyone can get CDI, but some people have a higher risk. You may be at a higher risk for getting CDI if you:

• Have taken antibiotics in the past 30 days.
• Have a weak immune system from an ongoing illness.
• Have been in the hospital or a long-term care facility.
• Are age 65 or older.
• Have inflammatory bowel disease.
• Have had CDI one or more times in the past.
• Take a medicine to lower the amount of acid in your stomach, such as Prevacid®, Tagamet®, Prilosec®, or Nexium®. These medicines are called proton pump inhibitors or PPIs.

Can CDI come back after treatment?

For some people, CDI may return after treatment ends. Out of every 10 people who have had CDI in the past, as many as 3 to 6 people will have CDI again.

Understanding Your Options

How is CDI treated?

There are several treatments for CDI, including:

• Antibiotics to treat your CDI.
• Probiotics to take with an antibiotic to help keep your CDI from coming back.
• Fecal microbiota transplantation if antibiotics do not help your CDI or if your CDI keeps coming back.

What about antidiarrhea medicines?
Talk with your health care professional before taking any over-the-counter antidiarrhea medicines (such as Pepto-Bismol®, Kaopectate®, or Imodium®) for your CDI. These medicines may make CDI worse.

Antibiotics

If your CDI happened after you took an antibiotic, your health care professional may have you stop taking the antibiotic. Your health care professional will likely give you a different antibiotic to help treat your CDI. The antibiotic your doctor recommends may depend on the availability and cost of the antibiotic, what is covered by your health insurance plan, and how severe your CDI is.

Note: You should never stop taking any medicine without first talking with your health care professional.

Your health care professional will likely first recommend one of these antibiotics:

• Metronidazole (Flagyl®)
• Vancomycin (Vancocin®)

If metronidazole (Flagyl®) and vancomycin (Vancocin®) do not work to treat your CDI, your health care professional may recommend a newer kind of antibiotic:

• Fidaxomicin (Dificid®)
  • Fidaxomicin is much more expensive than both metronidazole and vancomycin. The cost to you depends on your health insurance plan.
  • Most health insurance plans will only cover fidaxomicin after you have tried metronidazole and vancomycin and neither one worked.

What did researchers find about antibiotics for CDI?

What are possible side effects of antibiotics to treat CDI?

The U.S. Food and Drug Administration (FDA) lists the following possible side effects of antibiotics to treat CDI. Just because a side effect is possible does not mean you will have it.

Probiotics

To help keep your CDI from coming back, your health care professional may suggest that you take probiotics along with the antibiotic to treat your CDI. Probiotics are healthy bacteria and other microscopic organisms that are normally found in your body. Probiotics are taken as dietary supplements. They come in some foods, such as yogurt, kefir (a drink made from fermented milk), soy drinks, buttermilk, some soft cheeses, and enriched milk. Probiotics also come as a pill you can take by mouth.

Note: The FDA approves the quality and safety of all prescription and over-the-counter medicines. But dietary supplements such as probiotics do not need FDA approval. When considering a dietary supplement, always check the label to see if the supplement has been tested for quality.

What did researchers find about probiotics?

The chart below lists some different types of probiotics and what researchers found about each.

What are possible side effects of probiotics?

Probiotics are usually safe for people who are generally healthy. Possible side effects of probiotics may include gas and bloating.

For people with a weak immune system, S. boulardii may cause severe side effects, such as a life-threatening fungal infection. It is important to always talk with your health care professional before taking probiotics.

Fecal Microbiota Transplantation

Fecal microbiota transplantation (FMT) is a newer type of treatment for CDI. Your health care professional may suggest FMT if antibiotics do not help your CDI or if your CDI keeps coming back. FMT is meant to help put some of the "good" bacteria back into your intestines. To do this, your health care professional takes a small amount of stool containing healthy bacteria from a person who does not have CDI and places it into your intestine. The stool may come from a close family member or from a healthy donor from a stool bank.

What did researchers find about FMT?

Researchers found that FMT appears to help stop diarrhea and to help keep CDI from coming back, but more research is needed to know this for sure.

What are possible side effects of FMT?

There is not much research on the short-term and long-term side effects of FMT. There is a chance of bleeding or infection, but the risk is low.

Other possible side effects of FMT may include:

• Diarrhea
• Stomach cramps
• Nausea
• Belching
• Constipation

What can I do to help prevent CDI?

• Only take antibiotics when your health care professional prescribes them. Take all antibiotics exactly as instructed. Never stop taking an antibiotic without first talking with your health care professional (even if you start to feel better).
• When caring for someone with CDI:
  • Wash your hands often. To help prevent CDI, it is best to use soap and water instead of hand sanitizer.
  • Clean often-touched surfaces such as door knobs, sinks, and countertops with a disinfectant, such as bleach.

Making a Decision

What should I think about when deciding on treatment for my CDI?

You and your health care professional can decide what might be best to treat CDI and help keep it from coming back. Talk with your health care professional about whether this is your first time to have CDI or whether you have had CDI in the past and it has come back.

Ask your health care professional

• If my CDI happened after taking an antibiotic, should I stop taking the antibiotic? Is there a different antibiotic I can take with less risk of causing CDI?
• Which other antibiotic might be best to help treat my CDI?
• What possible side effects of the antibiotic for CDI should I watch for?
• Might probiotics help keep my CDI from coming back?
• If antibiotics do not work or if my CDI keeps coming back, might FMT help?
• What possible side effects from FMT would I need to watch for?

C. diff germs are carried from person to person in poop.

If someone with C. diff (or caring for someone with C. diff) doesn’t clean their hands with soap and water after using the bathroom, they can spread the germs to people and things they touch.

C. diff can also live on people’s skin. People who touch an infected person’s skin can pick up the germs on their hands. Taking a shower with soap and water can reduce the C. diff on your skin and lessen the chance of it spreading.

C. diff germs are so small relative to our size that if you were the size of the state of California, a germ would be the size of a baseball home plate. There’s no way you can see C. diff germs on your hands, but that doesn’t mean they’re not there.

Washing with soap and water is the best way to prevent the spread from person to person.

Remember: you can come in contact with C. diff germs—and even carry them on, or in, your body—and not get sick. But that doesn’t mean you can’t spread the germs to others.

How long can C. diff germs live?

When C. diff germs are outside the body, they become spores. These spores are an inactive form of the germ and have a protective coating allowing them to live for months or sometimes years on surfaces and in the soil.

The germs become active again when these spores are swallowed and reach the intestines.

Healthy people will often not be infected even if the spores reach their intestines, but if your immune system is weakened or you’ve recently taken antibiotics, you could get sick.

How do I make sure I don't spread C. diff?

In a healthcare setting

Make sure all healthcare professionals clean their hands before and after caring for you. Ask your healthcare professionals to clean their hands if you don’t see them do so.

While caring for you and other patients with C. diff, healthcare professionals will use certain precautions, such as wearing a gown and gloves, to prevent the spread of C. diff to themselves and to other patients.

If you’re in the hospital, wash your hands with soap and water every time you use the bathroom and always before you eat. Remind relatives and friends taking care of you to do the same.

At home

Wash your hands with soap and water every time you use the bathroom and always before you eat. Remind relatives and friends taking care of you to do the same.

Try to use a separate bathroom if you have diarrhea. If you can’t, be sure the bathroom is well cleaned before others use it.

Take showers and wash with soap to remove any C. diff germs you could be carrying on your body.

How do I kill C. diff germs at home?

Finding C. diff germs in the home is not unusual, even when no one in the home has been ill with C. diff. Most healthy adults who come in contact with C. diff in the home won’t get sick.

Hospitals use special cleaning products to kill C. diff, but you can make a cleaner at home. Mix 1 part bleach to 10 parts water (for example, 1/4 cup bleach poured into 2 1/2 cups water).

Surfaces

Focus on regularly cleaning items that are touched by hands. These include but are not limited to:

• doorknobs
• electronics (be careful because bleach can damage many electronics and plastics)
• refrigerator handles
• shared cups
• toilet flushers and toilet seats

Laundry

If someone in your house has C. diff, wash items they touch before others use them. These include but are not limited to:

• bed linens
• towels
• household linens
• clothing, especially underwear

If these items have visible poop, rinse them well before washing.

Then launder in a washer and dryer, using the hottest water that is safe for those items. Use chlorine bleach if the items can be safely washed with it.

Consider wearing gloves when handling dirty laundry and always wash your hands with soap and water after, even if you use gloves.

It’s OK to take clothes to a dry cleaner that were worn by a patient infected with C. diff. However, dry cleaning isn’t as effective as other methods at killing the spores. Therefore, this option should be used only for clothes that can’t be machine-washed.

When can I go back to work? When can my children go back to school?

You and your children should return to work or school only when your symptoms have stopped.

Can I still spread C. diff after treatment?

The risk of spreading C. diff after completing treatment is low. But if you’re carrying the germ even without symptoms, you can still spread it to others.

So always wash your hands with soap and water before you eat and after you use the bathroom. Showering and washing with soap is the best way to remove any C. diff germs you might be carrying on your body.

After treatment, can I be tested again to make sure I’m cured?

No, because once you recover from your C. diff infection, you could still be carrying the germs.

A test would only show the germs are still there, but not whether you’re likely to become sick again.

Will I get C. diff again?

About one in 6 people who’ve had C. diff will get infected again in the subsequent 2-8 weeks. This can be a relapse of their original infection, or it can happen when they come in contact with C. diff again.

The best way to be sure you don’t get C. diff again is to work with your healthcare professional to avoid taking unnecessary antibiotics and to wash your hands with soap and water every time you use the bathroom and before you eat anything.

If you’ve had a C. diff infection, tell your healthcare professional. This important information will help them make the best decisions when prescribing antibiotics in the future.

This is as important at your dentist’s office as it is when you see your primary care doctor.

How can I avoid getting C. diff again?

The best way to be sure you don’t get C. diff again is to:

• Work with your healthcare professional to avoid taking unnecessary antibiotics.
• Tell your healthcare professional if you’ve had a C. diff infection. This important information will help them make the best decisions when prescribing antibiotics in the future.
• Wash your hands with soap and water every time you use the bathroom and before you eat anything.

Should I report my C. diff infection to CDC?

No. Hospitals are required to report C. diff infections to CDC’s National Healthcare Safety Network (NHSN). Some states also require other healthcare facilities to report C. diff infections, and the requirements vary from state to state. Contact your local or state health department for information specific to your state.

Marty Katz's quick action got his infection under control

When Marty Katz returned from a vacation to Puerto Vallarta, Mexico, in April 2017, he didn't feel well. He had diarrhea and felt fatigued. Initially, he assumed it was food poisoning or something else related to his trip. But it turned out to be something much more serious.

"At one point, I could hardly get out of the bed to go to the bathroom. It was extremely debilitating."

"I was on my way home after a very long day traveling, felt tired, and I didn't have any other symptoms than diarrhea. But it progressed over the next few days. I started getting weaker, had almost constant diarrhea, my stool became very dark, and I didn't have an appetite," Marty, who is 76 years old, said. He called his gastroenterologist, described his symptoms, and was in the next day for testing.

"At one point, I could hardly get out of the bed to go to the bathroom," Marty said. "It was extremely debilitating."

After performing blood tests, stool tests, and a sigmoidoscopy, a procedure that looks inside your lower colon and rectum using a flexible tube, Marty's gastroenterologist confirmed that he had contracted Clostridium difficile (C. difficile).

Marty was prescribed two antibiotics for an upper respiratory infection before his trip to Mexico. This combination, Marty's gastroenterologist determined, had facilitated the C. difficile. He immediately took Marty off the two antibiotics he was on. He then prescribed another targeted antibiotic to cure the C. difficile and a probiotic to prevent further complications.

"It took about seven to 10 days to get it under control," Marty said. "My gastroenterologist warned me that it can come back, so I've been staying on probiotics ever since and so far, I've been fine."

While many C. difficile patients go to the hospital to improve, Marty was able to go home where his fiancee, Judi, took care of him 24/7. Judi flew down from Philadelphia, where she was living at the time, to stay with Marty in his Hilton Head, South Carolina, home.

"We came back from Mexico on a Tuesday, and by that Saturday, Judi came down to South Carolina because of how sick I was," Marty said. In addition to looking after Marty, Judi kept everything as clean as possible to prevent transmission since C. difficile is highly contagious.

Although Marty didn't know much about C. difficile before contracting it last year, he is no stranger to microorganisms. "My background is in microbiology. I worked for the Food and Drug Administration as a biologist for 35 years and before that, I worked as a research biologist for the U.S. Navy," he said.

Marty's message to others who think they may have C. difficile is to see your provider as soon as possible. "If you start developing constant diarrhea that's black, get yourself to a provider immediately," Marty said. "You need to get it diagnosed as quickly as you can."

With C. difficile out of the way, Marty and Judi can focus on wedding planning and preparing for newlywed life in two cities: Philadelphia in the warmer months and Hilton Head in the cooler ones.

Marty Katz battled a C-diff infection in April 2017.

What is C. diff?

C. diff is a spore-forming, Gram-positive anaerobic bacillus that produces two exotoxins: toxin A and toxin B. It is a common cause of antibiotic-associated diarrhea (AAD). It accounts for 15 to 25% of all episodes of AAD.

What diseases result from C. diff infection (CDI)?

• pseudomembranous colitis (PMC)
• toxic megacolon
• perforations of the colon
• sepsis
• death (rarely)

What are the main clinical symptoms?

• watery diarrhea
• fever
• loss of appetite
• nausea
• abdominal pain/tenderness

Which patients are at increased risk for CDI?

The risk for disease increases in patients with:

• antibiotic exposure (e.g., fluoroquinolones, third/fourth generation cephalosporins, clindamycin, carbapenems)
• gastrointestinal surgery/manipulation
• long length of stay in healthcare settings
• a serious underlying illness
• immunocompromising conditions
• advanced age

What are the differences between colonization and infection?

• Colonization with C. diff is more common than infection. Colonized patients do not have disease caused by C. diff and often exhibit NO clinical symptoms (asymptomatic) of infection (e.g., diarrhea); colonized patients do test positive for the C. diff organism or its toxin.

  Patients with infection exhibit clinical symptoms and test positive for the C. diff organism or its toxin.

Which laboratory tests are commonly used for diagnosis?

• Molecular tests: FDA-approved PCR assays, which test for the genes encoding toxin, are same-day tests that are highly sensitive and specific for the presence of a toxin-producing C. diff organism. Molecular assays can be positive for C. diff in individuals who are asymptomatic and do not have infection. Patients with other causes of diarrhea might be positive, which could lead to over-diagnosis and treatment. When using multi-pathogen (multiplex) molecular methods, the results should be read with caution as the pre-test probability of C. diff infection might be less.

• Antigen detection for C. diff: These are rapid tests (1 hour) that detect the presence of C. diff antigen glutamate dehydrogenase (GDH). Because results of antigen testing alone are nonspecific, antigen assays have been employed in combination with tests for toxin detection, PCR, or toxigenic culture in two-step testing algorithms.
  
• Toxin testing for C. diff:
  • Tissue culture cytotoxicity assay detects toxin B only. This assay requires technical expertise to perform, is costly, and requires 24 to 48 hours for a final result. It does provide specific and sensitive results for CDI. While it served as a historical gold standard for diagnosing clinically significant disease caused by C. diff, it is recognized as less sensitive than PCR or toxigenic culture for detecting the organism in patients with diarrhea.
  • Enzyme immunoassay detects toxin A, toxin B, or both A and B. Due to concerns over toxin A-negative, B-positive strains causing disease, most laboratories employ a toxin B-only or A and B assay. Because these are same-day assays that are relatively inexpensive and easy to perform, they are popular with clinical laboratories. However, there are increasing concerns about their relative insensitivity (less than tissue culture cytotoxicity and much less than PCR or toxigenic culture).
  • C. diff toxin is very unstable. The toxin degrades at room temperature and might be undetectable within two hours after collection of a stool specimen. False-negative results occur when specimens are not promptly tested or kept refrigerated until testing can be done.
    
• Stool culture for C. diff: While this is the most sensitive test available, it is the one most often associated with false-positive results due to the presence of nontoxigenic C. diff strains. However, this can be overcome by testing isolates for toxin production (i.e. so-called “toxigenic culture”). Nonetheless, stool cultures for C. diff are labor-intensive, require an appropriate culture environment to grow anaerobic microorganisms, and have a relatively slow turnaround time (i.e. results available in 48 to 96 hours), making them less clinically useful overall. Results of toxigenic cultures do serve as a gold standard against which other test modalities are compared in clinical trials of performance.

How is C. diff transmitted?

C. diff is shed in feces. Any surface, device, or material (such as commodes, bathtubs, and electronic rectal thermometers) that becomes contaminated with feces could serve as a reservoir for the C. diff spores. C. diff spores can also be transferred to patients mainly via the hands of healthcare personnel who have touched a contaminated surface or item.

How is CDI treated?

In about 20% of patients, CDI will resolve within two to three days of discontinuing the antibiotic to which the patient was previously exposed. The infection can usually be treated with an appropriate course (about 10 days) of antibiotics, including oral vancomycin or fidaxomicin. After treatment, repeat C. diff testing is not recommended if the patient’s symptoms have resolved, as patients often remain colonized.

What are the steps to prevent spread?

If a patient has had ≥ 3 stools in 24 hours:

• Order a C. diff test if other etiologies of diarrhea are ruled out.
• Isolate patients with C. diff immediately, even if you only suspect CDI.
• Wear gloves and gowns when treating patients with C. diff, even during short visits. Gloves are important because hand sanitizer doesn’t kill C. diffand handwashing might not be sufficient alone.
• In patient being evaluated for C. diff, reassess correctness of antibiotics.

If the patient is positive for CDI:

• Continue isolation and contact precautions.
• Use antibiotics judiciously.
• Clean room surfaces thoroughly on a daily basis while treating a patient with C. diffand upon patient discharge or transfer using an EPA-approved spore-killing disinfectant.
• When a patient transfers, notify the new facility if the patient has or had a C. diff infection.

CDIs can be prevented by using infection control recommendations and more careful antibiotic use.

How can CDIs be prevented in hospitals and other healthcare settings?

• Use antibiotics appropriately.

• Use contact precautions for patients with known or suspected CDI:
  • Place these patients in private rooms. If private rooms are not available, they can be placed in rooms (cohorted) with other CDI patients.
  • Wear gloves and a gown when entering CDI patient rooms and during their care.
  • As no single method of hand hygiene will eliminate all C. diff spores, using gloves to prevent hand contamination remains the cornerstone for preventing C. diff transmission via the hands of healthcare personnel.
  • Always perform hand hygiene after removing gloves.
• If your institution experiences an outbreak, consider using soap and water instead of alcohol-based hand sanitizers for hand hygiene after removing gloves while caring for patients with CDI.
• Dedicate or perform cleaning and disinfection of any shared medical equipment between patients.
• Continue CDI precautions at least until diarrhea ceases.
  • Because CDI patients continue to shed the organism for a number of days following cessation of diarrhea, some institutions routinely continue isolation and contact precautions for either several days beyond symptom resolution or until discharge, depending upon the type of setting and average length of stay.
• Implement an environmental cleaning and disinfection strategy.
  • Ensure adequate cleaning and disinfection of environmental surfaces and reusable devices, especially items likely to be contaminated with feces and surfaces that are touched frequently.
    • Ensure daily and terminal cleaning of patient rooms.
  • Use an Environmental Protection Agency (EPA)-registered disinfectant with a sporicidal claim for environmental surface disinfection after cleaning in accordance with label instructions.
  • Follow the manufacturer’s instructions for disinfection of endoscopes and other devices.

What can I use to clean and disinfect surfaces and devices?

Surfaces should be kept clean, and body substance spills should be managed promptly, as outlined in CDC’s Guidelines for Environmental Infection Control in Health-Care Facilities. Routine cleaning should be performed prior to disinfection. EPA-registered disinfectants with a sporicidal claim have been used with success for environmental surface disinfection in those patient-care areas where surveillance and epidemiology indicate ongoing transmission of C. diff.

Note: EPA-registered disinfectants (List K) are recommended for use in patient-care areas. When choosing a disinfectant, check product labels for inactivation claims, indications for use, and instructions.