Schistosomiasis
What is Schistosomiasis?
Schistosomiasis is a parasitic infection caused by tiny flatworms called schistosomes. These parasites live in freshwater snails found in rivers, lakes, and ponds in certain parts of the world. When people swim, bathe, or wash clothes in contaminated water, the parasites can penetrate their skin and enter the bloodstream.
Once inside the body, the parasites mature into adult worms that live in blood vessels near the intestines or bladder. These worms lay eggs that can become trapped in body tissues, causing inflammation and damage to organs over time. Schistosomiasis is also called snail fever or bilharzia.
The infection affects over 200 million people worldwide, mostly in tropical and subtropical regions. It is most common in Africa, South America, the Caribbean, the Middle East, and parts of Asia. Early detection and treatment can prevent serious complications and long-term organ damage.
Symptoms
- Fever and chills during the early infection phase
- Skin rash or itching where the parasites entered the body
- Cough and difficulty breathing
- Muscle and joint pain
- Abdominal pain and cramping
- Blood in urine or stool
- Diarrhea or constipation
- Fatigue and weakness
- Enlarged liver or spleen
- Unexplained weight loss
Many people have no symptoms in the early stages of infection. Symptoms may not appear until weeks or months after exposure to contaminated water. Some people carry the infection for years without knowing it, which is why testing is important for anyone who has traveled to areas where schistosomiasis is common.
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Causes and risk factors
Schistosomiasis is caused by parasitic flatworms that complete part of their life cycle in freshwater snails. When infected snails release the parasites into water, they can burrow through human skin in as little as 30 seconds. Activities like swimming, bathing, washing clothes, or wading in contaminated water put people at risk. The parasites cannot spread from person to person.
Risk factors include living in or traveling to tropical and subtropical areas where schistosomiasis is common, especially parts of Africa, South America, the Middle East, and Asia. People who work in agriculture, fishing, or water-related activities face higher exposure. Poor sanitation and lack of clean water increase the spread of infection. Children who play in contaminated water are particularly vulnerable to infection.
How it's diagnosed
Schistosomiasis is diagnosed through a combination of travel history, symptoms, and laboratory testing. Doctors will ask about recent travel to areas where the infection is common and any contact with freshwater. Blood tests can reveal elevated eosinophils, a type of white blood cell that increases during parasitic infections. High eosinophil levels often indicate active infection and help doctors assess the severity of the parasitic burden.
Stool or urine samples can be examined under a microscope to look for parasite eggs. Concentration and permanent smear techniques help detect eggs that might otherwise be missed. Rite Aid offers testing that includes eosinophil counts and stool analysis to screen for schistosomiasis in people who may have been exposed. Getting tested is especially important for anyone with symptoms after traveling to areas where the infection is found.
Treatment options
- Antiparasitic medication like praziquantel to kill the worms
- Corticosteroids to reduce inflammation during severe acute infection
- Treatment of complications like liver or bladder damage
- Follow-up testing to confirm the infection has cleared
- Avoiding contaminated water sources during and after treatment
- Nutritious diet to support immune function and recovery
- Adequate rest to help the body heal
- Staying hydrated, especially if experiencing diarrhea
Concerned about Schistosomiasis? Get tested at Rite Aid.
- Simple blood draw at your nearest lab
- Results in days, not weeks
- Share results with your doctor
Frequently asked questions
Schistosomiasis is a parasitic infection caused by flatworms that live in freshwater snails. You get it when parasites in contaminated water penetrate your skin during activities like swimming or bathing. The infection is most common in tropical and subtropical regions of Africa, South America, and Asia. It cannot spread from person to person.
The first signs often include a skin rash or itching where the parasites entered the body. Within a few weeks, you may develop fever, chills, cough, and muscle pain as the infection spreads. Many people have no early symptoms at all. Blood in urine or stool may appear later as the infection progresses.
Yes, blood tests can help detect schistosomiasis by measuring eosinophils, white blood cells that increase during parasitic infections. Elevated eosinophil levels suggest active infection and indicate the severity of the parasitic burden. Rite Aid offers blood testing that includes eosinophil counts to screen for this condition. Stool or urine samples are also examined for parasite eggs to confirm the diagnosis.
Schistosomiasis is treated with antiparasitic medication called praziquantel, which kills the worms. Most people need only one or two doses to clear the infection. In severe cases, corticosteroids may be used to reduce inflammation. Follow-up testing ensures the treatment worked and the infection is gone.
No, schistosomiasis does not go away on its own without treatment. The parasites can live in your body for years, continuing to lay eggs that damage organs. Untreated infection can lead to serious complications like liver damage, kidney failure, or bladder cancer. Treatment with medication is necessary to eliminate the parasites.
Untreated schistosomiasis can cause serious long-term damage to the liver, intestines, bladder, and other organs. Chronic infection may lead to liver scarring, kidney failure, increased cancer risk, and reproductive problems. Children with untreated infection may experience growth delays and learning difficulties. Early treatment prevents these complications and supports full recovery.
Avoid swimming, bathing, or wading in freshwater lakes, rivers, and ponds in areas where schistosomiasis is common. Use bottled or boiled water for drinking and bathing when possible. If you must enter potentially contaminated water, dry off vigorously with a towel immediately afterward. Applying insect repellent before water contact may offer some protection.
People who live in or travel to tropical and subtropical areas where the infection is common face the highest risk. Those who work in agriculture, fishing, or other water-related activities have greater exposure. Children who play in contaminated water are particularly vulnerable. Communities with poor sanitation and limited access to clean water also experience higher infection rates.
Most people feel better within a few weeks after starting antiparasitic treatment. Complete recovery depends on how long you had the infection and whether it caused organ damage. Mild cases may resolve quickly, while chronic infections may require months of healing. Follow-up testing at 3 to 6 months confirms the infection is fully cleared.
Yes, you can get schistosomiasis again if you are re-exposed to contaminated water after treatment. Having the infection once does not provide lasting immunity. People living in areas where schistosomiasis is common may need periodic screening and treatment. Avoiding contact with freshwater in affected regions is the best prevention strategy.