Blastocystis hominis is a parasite that can be found in stools of healthy people and in those with gastrointestinal problems such as diarrhea and stomach pain. Blastocystis can remain in the intestines for months or even years. It is not evident how the parasite spreads but is found predominantly in areas with inadequate sanitation and personal hygiene.
Symptoms
Symptoms that can be associated with blastocystis hominis are stomach cramps, diarrhea, nausea, bloating, excess gas, anal itching and fatigue. Diarrhea can lead to dehydration, so If these symptoms last three or more days you should consult your doctor.
Diagnosis
A stool sample is normally taken over a three-day period. The samples are tested for parasites and their eggs. If the stool sample does not show evidence of a parasite, your doctor might request and endoscopy. The test involves a tube inserted into your rectum or into your mouth to look for the cause of your symptoms. Your doctor can also order blood tests to look for antigens and antibodies. Your body will try to fight any parasitic infections, so antigens and antibodies will form and the lab can detect the parasites responsible. A CT or MRI scan may be requested if the parasite is causing swelling or scarring of internal organs.
Treatment
Blastocystis hominis is normally treated with antibiotics such as Flagyl or a combination of drugs like Bactrim and Yodoxin. The response of these medications varies from each person, so keep your doctor informed if you don’t see any improvement.
Prevention
Prevention of blastocystis hominis and other parasites can be done if certain precautions are used when traveling to high-risk countries. Do not eat undercooked meat or fish, unpasteurized milk or ice cream, food from street vendors and fruits such as berries or grapes and salads. Eat foods that are cooked through and served hot and fruits that you can peel like bananas and oranges. Do not drink water from the tap and keep your mouth closed when showering. Use bottled water to drink and to brush your teeth. Sodas and beer should be safe in their original container as long as you break the seal yourself. Wash your hands frequently and always after using the toilet or changing a diaper. If a washing facility is not available, use a hand sanitizer.