What is schistosomiasis?
Schistosomiasis is an infection caused by a tiny parasite called a fluke.
Flukes are common in rivers and lakes in tropical areas in South America, Africa, and Asia
You can get schistosomiasis by swimming or bathing in water that has flukes in it
The flukes burrow into your skin and travel through your blood
They eventually end up in small blood vessels inside your intestines or your bladder
Symptoms first include an itchy rash, followed by fever, chills, muscle aches, weakness, and belly pain
Doctors test samples of your stool (poop) and urine (pee) for fluke eggs
Doctors treat you with antiparasite medicine to kill the flukes
What causes schistosomiasis?
Schistosomiasis is caused by a parasite called a fluke, which is a type of roundworm. Adult flukes are about ¼ to ¾ of an inch long (1 to 2 centimeters).
You get schistosomiasis from swimming, wading, or bathing in fresh water that has these flukes.
While you're in the water, the flukes get on your skin
The flukes burrow into your skin, and then they travel through your blood to your bladder or intestine
The flukes in your bladder or intestine lay many eggs:
The eggs irritate your tissues and cause ulcers, scars, and bleeding
Some eggs flow from the intestine to the liver
The eggs leave your body in your stool or urine
If your urine or stool get into fresh water, the eggs hatch and grow up to be able to infect somebody else
When eggs flow from the intestine to the liver, your liver can become inflamed. That can lead to scarring and increased pressure in the portal vein. The portal vein carries blood between the intestinal tract and the liver. High blood pressure in the portal vein (called portal hypertension) can cause your spleen to enlarge. It can also cause bleeding from veins in your esophagus (the "food pipe" that connects your throat and your stomach).
What are the symptoms of schistosomiasis?
Most people have no symptoms. When the flukes first enter your skin, you may get:
An itchy rash
After a few weeks, you may start to feel sick and have symptoms such as:
Fever
Chills
Cough
Muscle aches
Belly pain
Depending on where the adult flukes are in your body you may have:
Pain when peeing and blood in your urine
Bloody diarrhea (loose, watery stool)
An enlarged liver and spleen
A bad infection can make you lose enough blood to develop:
Schistosomiasis can also affect other organs, such as your lungs, spinal cord, kidneys, and brain.
How can doctors tell if I have schistosomiasis?
Doctors suspect schistosomiasis from your symptoms, especially if you've recently been swimming or bathing in possibly infected water. Doctors check for schistosomiasis by looking for fluke eggs in your:
Stool
Urine
Intestine or bladder tissue
Sometimes, doctors also do blood tests, ultrasound Ultrasonography Ultrasonography is a safe imaging test that uses sound waves to create a moving picture of the insides of your body. Ultrasonography doesn't use radiation (x-rays). Ultrasonography is also called... read more 
, or CT scan Computed Tomography A CT scan uses a large machine shaped like a large donut to take x-rays from many angles. A computer then takes the x-rays and creates many detailed pictures of the inside of your body. Each... read more to see how severe your infection is.
How do doctors treat schistosomiasis?
Doctors treat schistosomiasis using:
Antiparasite medicine
Doctors may also test your stool or urine 1 or 2 months later to make sure it no longer has any fluke eggs in it.
How can I prevent schistosomiasis?
You can help prevent schistosomiasis by:
Not swimming, bathing, or wading in areas known to contain flukes
In areas where flukes are a problem, boiling water or storing it for a day or two before washing with it
Drying off vigorously with a towel if you accidentally get into contaminated water—this helps remove parasites before they burrow through your skin
When the eggs hatch in water, the flukes infect snails. So sometimes people put chemicals that kill snails in bodies of fresh water known to contain flukes.
