Balantidiasis is a rare intestinal infection caused by the bacterium, Balantidium coli, a single-celled parasite (ciliate protozoan) that frequently infects pigs but on occasion (rarely) infects humans. Some infected people may have no symptoms or only mild diarrhea and abdominal discomfort but others may experience more severe symptoms reminiscent of acute inflammation of the intestines. Symptoms of Balantidiasis may be similar to those of other infections that cause intestinal inflammation, for example, amoebic dysentery.
Symptoms
Most people with Balantidiasis are asymptomatic or present mild symptoms. Some individuals may become acutely ill with abnormally high temperatures, nausea, vomiting, abdominal pain, and bloody diarrhea. Such conditions may result in the excessive loss of water from the body (dehydration) and extreme exhaustion (prostration), especially if B. coli attacks the intestinal lining causing inflammation and possibly “crater-like” areas of damage (ulceration). In very severe cases, the ulcers may be deep enough to puncture the intestinal wall (perforation) resulting in acute inflammation of the peritoneum, the membrane that lines the abdomen (peritonitis). Occasionally, the ulcer may diminish lung function.
Usually asymptomatic in immunocompetent individuals, the symptoms of balantidiasis include
- Intermittent diarrhea
- Constipation
- Vomiting
- Abdominal pain
- Anorexia
- Weight loss
- Headache
- Colitis
- Marked fluid loss
The most common ones are intermittent diarrhea and constipation or inflammation of the colon combined with abdominal cramps and bloody stools
Causes
Balantidiasis is a rare infectious disease caused by the single-celled (protozoan) parasite Balantidium coli. This parasite may be passed directly to humans by contact with pig feces or indirectly by drinking contaminated water. Poor nutrition, a compromised immune system, or other illnesses may make a person vulnerable to more severe symptoms of this disease.
Transmission
Balantidium is the only ciliated protozoan known to infect humans. Balantidiasis is a zoonotic disease and is acquired by humans via the feco-oral route from the normal host, the pig, where it is asymptomatic. “Contaminated water is the most common mechanism of transmission. Equally dangerous, however, is the ingestion of contaminated food.
Treatment
Balantidiasis can be diagnosed by laboratory testing of the stool. Immature B. coli parasites (trophozoites) are usually recoverable from the stool. A more complex and more invasive diagnostic method involves scraping the ulcer and examining the tissue for trophozoites.
The antibiotic drug most frequently used to treat Balantidiasis is tetracycline. When tetracycline cannot be given (i.e., allergy), replacement drug therapy may include the drugs iodoquinol or metronidazole. It is not necessary to isolate (quarantine) a person who has Balantidiasis. However, the feces of infected individuals must be disposed of so that they do not come into contact with drinking water or food supplies.
FAQ
What is Balantidium coli?
Balantidium coli is an intestinal protozoan parasite that causes the infection called balantidiasis. While this type of infection is uncommon in the United States, humans and other mammals can become infected with Balantidium coli by ingesting infective cysts from food and water that is contaminated by feces. Mostly asymptomatic, Balantidium infection can cause such symptoms as diarrhea and abdominal pain.
Where is Balantidium coli endemic?
Balantidium coli infection in humans is rare in the United States. Balantidium coli is found throughout the world, but it is most prevalent in tropical and subtropical regions and developing countries. Because pigs are an animal reservoir, human infections occur more frequently in areas where pigs are raised, especially if good hygiene is not practiced.
How is Balantidium coli transmitted?
Balantidium coli is transmitted through the fecal-oral route. Humans can become infected by eating and drinking contaminated food and water that has come into contact with infective animal or human fecal matter. Infection can occur in several ways, including the following examples:
- eating meat, fruits, and vegetables that have been contaminated by an infected person or contaminated by fecal matter from an infected animal,
- drinking and washing food with contaminated water, or
- having poor hygiene habits.
What are the signs and symptoms?
Most people infected with Balantidium coli experience no symptoms. Balantidium coli infects the large intestine in humans and produces infective microscopic cysts that are passed in the feces, potentially leading to re-infection or infection of others. People who are immune-compromised are the most likely to experience more severe signs and symptoms. These include persistent diarrhea, dysentery, abdominal pain, weight loss, nausea, and vomiting. If left untreated, perforation of the colon can occur.
Is there a test for Balantidium coli infection?
Yes. Stool samples can be examined by a laboratory. Microscopic examination can detect Balantidium coli in the stool.
Is this contagious?
Yes. Balantidium coli is contagious by the fecal-oral route.
Is there treatment?
Yes. The three medications often used to treat Balantidium coli are tetracycline, metronidazole, and iodoquinol. See your health care provider for treatment.
How can I prevent Balantidium coli?
Balantidium coli infection can be prevented when traveling by following good hygiene practices. Wash your hands with soap and warm water after using the toilet, changing diapers, and before handling food. Teach children the importance of washing hands to prevent infection. Wash all fruits and vegetables with clean water when preparing or eating them, even if they have a removable skin.
Handwashing is one of the best ways to protect yourself and your family from getting sick. Learn when and how you should wash your hands to stay healthy.
How Germs Spread
Washing hands can keep you healthy and prevent the spread of respiratory and diarrheal infections. Germs can spread from person to person or from surfaces to people when you:
- Touch your eyes, nose, and mouth with unwashed hands
- Prepare or eat food and drinks with unwashed hands
- Touch surfaces or objects that have germs on them
- Blow your nose, cough, or sneeze into hands and then touch other people’s hands or common objects
Key Times to Wash Hands
You can help yourself and your loved ones stay healthy by washing your hands often, especially during these key times when you are likely to get and spread germs:
- Before, during, and after preparing food
- Before and after eating food
- Before and after caring for someone at home who is sick with vomiting or diarrhea
- Before and after treating a cut or wound
- After using the toilet
- After changing diapers or cleaning up a child who has used the toilet
- After blowing your nose, coughing, or sneezing
- After touching an animal, animal feed, or animal waste
- After handling pet food or pet treats
- After touching garbage
This list of key times to wash hands was developed based on data from a number of studies. There may be other key times when it is important to wash hands during the COVID-19 pandemic.
To prevent the spread of germs during the COVID-19 pandemic, you should also wash your hands with soap and water for at least 20 seconds:
- Before touching your eyes, nose, or mouth
- After touching your mask
- After leaving a public place
- After touching objects or surfaces that may be frequently touched by other people, such as door handles, tables, gas pumps, shopping carts, or electronic cashier registers/screens
If soap and water are not readily available, use a hand sanitizer with at least 60% alcohol to clean your hands.
Follow Five Steps to Wash Your Hands the Right Way
Washing your hands is easy, and it’s one of the most effective ways to prevent the spread of germs. Clean hands can help stop germs from spreading from one person to another and in our communities—including your home, workplace, schools, and childcare facilities.
Follow these five steps every time.
- Wet your hands with clean, running water (warm or cold), turn off the tap, and apply soap.
- Lather your hands by rubbing them together with the soap. Lather the backs of your hands, between your fingers, and under your nails.
- Scrub your hands for at least 20 seconds. Need a timer? Hum the “Happy Birthday” song from beginning to end twice.
- Rinse your hands well under clean, running water.
- Dry your hands using a clean towel or air dry them.
Use Hand Sanitizer When You Can’t Use Soap and Water
Washing hands with soap and water is the best way to get rid of germs in most situations. If soap and water are not readily available, you can use an alcohol-based hand sanitizer that contains at least 60% alcohol. You can tell if the sanitizer contains at least 60% alcohol by looking at the product label.
Sanitizers can quickly reduce the number of germs on hands in many situations. However,
- Sanitizers do not get rid of all types of germs.
- Hand sanitizers may not be as effective when hands are visibly dirty or greasy.
- Hand sanitizers might not remove harmful chemicals from hands like pesticides and heavy metals.
Caution! Swallowing alcohol-based hand sanitizer can cause alcohol poisoning if more than a couple of mouthfuls are swallowed. Keep it out of reach of young children and supervise their use.
How to Use Hand Sanitizer
- Apply the gel product to the palm of one hand (read the label to learn the correct amount).
- Rub your hands together.
- Rub the gel over all the surfaces of your hands and fingers until your hands are dry. This should take around 20 seconds.
CDC’s Communication Materials
Watch and share hand hygiene videos to raise awareness and educate your community about healthy hygiene behaviors.
Rx has health promotion materials to encourage kids and adults to make handwashing part of their everyday lives.
- ORDER FREE posters and display them in highly visible public areas, such as school bathrooms,
work areas, and public restrooms. - Share social media graphics and messages.
- Print stickers and place clings on bathroom mirrors.
- Distribute fact sheets to share information about hand hygiene for specific audiences.
References
