Have you ever heard of snail fever? This disease is second to malaria as the most devastating parasitic disease

Photo Credits: Stanford, End.org

Name
Schistosomiasis, also known as bilharzia and snail fever

Transmission

• A disease caused by parasitic flatworms known as schistosomes
• These worms live in freshwater snails and leave the snails to contaminate the surrounding water
• The adult worms enter the human body when people’s skin comes in contact with contaminated freshwater (they penetrate the skin)
• The worms lay eggs in body tissues
• There are two types depending on the organs the parasite enters:
  • Intestinal: the worms infect the intestines
  • Urinary: the worms infect the bladder and urinary tract

Geography
Worldwide with increased prevalence in tropical and sub-tropical areas

Incubation Period
14 – 84 days

Signs and Symptoms

Days after becoming infected, symptoms include:

• Skin rash
• Itchy skin

1-2 months after infection, symptoms include:

• Fever
• Cough
• Muscle ache
• Chills

Without treatment, chronic schistosomiasis develops and symptoms include:

• Blood in urine
• Inability to urinate
• Blood in stool
• Enlarged liver
• Abdominal pain

When the worm eggs reach the spinal cord or brain (rare), symptoms include:

• Paralysis
• Spinal cord inflammation
• Seizures

In children, schistosomiasis can cause anemia and growth retardation. When it becomes chronic in people, urinary schistosomiasis can increase the risk of bladder cancer

Diagnosis
Laboratory analysis of stool and urine samples to detect the worm eggs

Treatment
Safe and effective medications, including a drug called Praziquantel, treat and completely cure the infection

Prognosis

• Without treatment, the infection can persist for years and lead to major complications as listed above
• With treatment, the infection clears

Prevention: What Can You Do?

• A vaccine is under trial, but the best prevention is to avoid contact with contaminated freshwater when in affected countries
  • Drink and use clean water (know your water source, boil for at least one minute if unsure)
  • Avoid swimming or wading in freshwater

Schistosomiasis In the News

• Stanford Researchers: Natural Predator Far Superior To Drugs
• Novel schistosomiasis vaccine: New phase of clinical studies

Sources:
http://www.cdc.gov/parasites/schistosomiasis/
http://www.who.int/schistosomiasis/en/