Navigate Up

Full Library - A-Z Index


Print This Page

Schistosomiasis

Schistosomiasis is infection with a type of Schistosoma parasite.

Alternative Names

Bilharzia; Katayama fever; Swimmer's itch; Blood fluke

Causes

You get a schistosoma infection through contact with contaminated water. The parasite in its infective stages is called a cercaria. It swims freely in open bodies of water.

On contact with humans, the parasite burrows into the skin, matures into another stage (schistosomula), then migrates to the lungs and liver, where it matures into the adult form.

The adult worm then migrates to its preferred body part, depending on its species. These areas include the bladder, rectum, intestines, liver, portal venous system (the veins that carry blood from the intestines to liver), spleen, and lungs.

Schistosomiasis is not usually seen in the United States. It is common in many tropical and subtropical areas worldwide.

Symptoms

Symptoms vary with the species of worm and the phase of infection.

  • Heavy infestation (many parasites) may cause fever, chills, lymph node enlargement, and liver and spleen enlargement.
  • Initial invasion of the skin may cause itching and a rash (swimmer's itch). In this condition, the schistosome is destroyed within the skin.
  • Intestinal symptoms include abdominal pain and diarrhea (which may be bloody).
  • Urinary symptoms may include frequent urination, painful urination (dysuria), and blood in the urine (hematuria).

Exams and Tests

  • Antibody test to check for signs of infection
  • Biopsy of tissue
  • Complete blood count (CBC) to check for signs of anemia
  • Eosinophil count to measure the number of certain white blood cells
  • Kidney function tests
  • Liver function tests
  • Stool examination to look for parasite eggs   
  • Urinalysis to look for parasite eggs 

Treatment

This infection is usually treated with the drug praziquantel. If the infection is severe or involves the brain, corticosteroids may be given.

Outlook (Prognosis)

Treatment before significant damage or severe complications occur usually produces good results.

Possible Complications

  • Bladder cancer
  • Chronic kidney failure
  • Chronic liver damage and an enlarged spleen
  • Colon (large intestine) inflammation with bloody diarrhea
  • Kidney and bladder obstruction
  • Pulmonary hypertension
  • Repeated blood infections can occur, because bacteria can enter the bloodstream through an irritated colon
  • Right-sided heart failure
  • Seizures

When to Contact a Medical Professional

Call your health care provider if you develop symptoms of schistosomiasis, especially if you have traveled to a tropical or sub-tropical area where the disease is known to exist or if you have been exposed to contaminated or suspect bodies of water.

Prevention

  • Avoid swimming or bathing in contaminated or potentially contaminated water
  • Avoid bodies of water of unknown safety

Snails are an intermediate host for the parasite. Getting rid of snails in bodies of water used by humans would help prevent infection.

References

Carvalho EM, Lima AAM. Schistosomiasis (Bilharziasis). In: Goldman L, Schafer AI, eds. Cecil Medicine. 24th ed. Philadelphia, Pa: Saunders Elsevier; 2011:chap 363.

Maguire JH. Trematodes (schistosomes and other flukes). In: Mandell GL, Bennett JE, Dolin R, eds. Principles and Practice of Infectious Diseases. 7th ed. Philadelphia, Pa: Elsevier Churchill Livingstone; 2009:chap 289.

Updated: 10/6/2012

David C. Dugdale, III, MD, Professor of Medicine, Division of General Medicine, Department of Medicine, University of Washington School of Medicine. Jatin M. Vyas, MD, PhD, Assistant Professor in Medicine, Harvard Medical School; Assistant in Medicine, Division of Infectious Disease, Department of Medicine, Massachusetts General Hospital. Also reviewed by David Zieve, MD, MHA, Medical Director, A.D.A.M. Health Solutions, Ebix, Inc.


©  UPMC | Affiliated with the University of Pittsburgh Schools of the Health Sciences
Supplemental content provided by A.D.A.M. Health Solutions. All rights reserved.

For help in finding a doctor or health service that suits your needs, call the UPMC Referral Service at 412-647-UPMC (8762) or 1-800-533-UPMC (8762). Select option 1.

UPMC is an equal opportunity employer. UPMC policy prohibits discrimination or harassment on the basis of race, color, religion, ancestry, national origin, age, sex, genetics, sexual orientation, marital status, familial status, disability, veteran status, or any other legally protected group status. Further, UPMC will continue to support and promote equal employment opportunity, human dignity, and racial, ethnic, and cultural diversity. This policy applies to admissions, employment, and access to and treatment in UPMC programs and activities. This commitment is made by UPMC in accordance with federal, state, and/or local laws and regulations.

Medical information made available on UPMC.com is not intended to be used as a substitute for professional medical advice, diagnosis, or treatment. You should not rely entirely on this information for your health care needs. Ask your own doctor or health care provider any specific medical questions that you have. Further, UPMC.com is not a tool to be used in the case of an emergency. If an emergency arises, you should seek appropriate emergency medical services.

For UPMC Mercy Patients: As a Catholic hospital, UPMC Mercy abides by the Ethical and Religious Directives for Catholic Health Care Services, as determined by the United States Conference of Catholic Bishops. As such, UPMC Mercy neither endorses nor provides medical practices and/or procedures that contradict the moral teachings of the Roman Catholic Church.

© UPMC
Pittsburgh, PA, USA UPMC.com