Blastocystis Hominis Infection

What is a Blastocystis Hominis Infection?

Blastocystis hominis is a microscopic parasite that can live in the human intestine. It’s found around the world, and many people who have the organism don’t experience any symptoms. However, under some conditions Blastocystis hominis infection appears to cause issues in the gastrointestinal tract.

Since it’s relatively common, many people carry Blastocystis hominis without knowing it. Those who are infected may have gotten the parasite from oral-fecal contact, such as by not washing hands before making food or eating. People who live in areas with poor sanitation may be at increased risk of getting infected with Blastocystis hominis.

What are the Symptoms of Blastocystis Hominis Infection?

Blastocystis hominis may be the cause of issues including nausea, diarrhea, cramping and bloating, gas, or loss of appetite. Some people may develop hives.

Since these symptoms are common to a number of illnesses, it may not be easy to determine if Blastocystis hominis is the cause. Any time you experience these types of symptoms for more than three days, you should consult your medical professional.

Blastocystis Hominis Infection Causes

Blastocystis was once looked at as a harmless yeast, yet it has come to light that it is actually a parasite feeding off of the host’s nutrients. Otherwise known as a protozoan, it can inhabit your gastrointestinal tract. Some protozoans are harmless while others can cause disease. There is no clear cut case that can say if blastocystis is a good or bad protozoan.

There is evidence of its presence in diarrhea patients or patients suffering from other gastrointestinal ailments. A person can also be a carrier of blastocystis and not even show any signs of symptoms.

Although it is not known for sure how this protozoan gets into the gastrointestinal system, doctors believe that it enters the system through oral-fecal contact, for example, if someone does not wash their hands thoroughly after using the bathroom and goes to prepare food.

It can also enter the system through drinking contaminated water. There is a higher presence of blastocystis in low hygiene situations or places of low sanitation.

How is a Blastocystis Hominis Infection Treated?

Most cases of Blastocystis hominis are mild and resolve on their own.

Treatment includes

Dehydration from nausea or diarrhea may be treated with oral or IV fluids.

Repeated or long-term cases are typically treated with prescription drugs. Your doctor will take a stool sample to confirm that you are infected with the parasite, and if so, prescribe a round of antibiotics or antiprotozoal drugs. These drugs may not work for all patients.

Infection with Blastocystis hominis is preventable by following good hygiene practices, including washing hands after using the bathroom and before handling food.

Blastocystis Hominis Infection Prevention

Since it is not entirely known how blastocystis hominis is spread, the best advice to prevent it is to maintain good personal hygiene, prepare your food in a clean environment, and do not drink dirty water.

If the food cannot be boiled, cooked, or peeled, don’t eat it. Try to avoid street vendors, unpasteurized dairy, raw meat or fish, shaved ice or frozen pops. If you are visiting a high risk country, then boil the water, and brush your teeth with bottled water.

If a person is infected with blastocystis hominis infection they are advised to stay away from daycare, schools, and work until diarrhea has passed for 24 hours. If you are in the food handling business then 48 hours should pass with no diarrhea or vomiting.

Last Reviewed:
September 13, 2016
Last Updated:
November 17, 2017