Schistosomiasis
Schistosomiasis, also known as snail fever, bilharzia, and Katayama fever, is a disease caused by parasitic flatworms called schistosomes. The urinary tract or the intestines may be infected. Symptoms include abdominal pain, diarrhea, bloody stool, or blood in the urine. Those who have been infected for a long time may experience liver damage, kidney failure, infertility, or bladder cancer. In children, it may cause poor growth and learning difficulty.
| Schistosomiasis | |
|---|---|
| Other names | Bilharzia, snail fever, Katayama fever |
| 11-year-old boy with abdominal fluid and portal hypertension due to schistosomiasis (Agusan del Sur, Philippines) | |
| Pronunciation |
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| Specialty | Infectious disease |
| Symptoms | Abdominal pain, diarrhea, bloody stool, blood in the urine |
| Complications | Liver damage, kidney failure, infertility, bladder cancer |
| Causes | Schistosomes from freshwater snails |
| Diagnostic method | Finding eggs of the parasite in urine or stool, antibodies in blood |
| Prevention | Access to clean water |
| Medication | Praziquantel |
| Frequency | 252 million (2015) |
| Deaths | 4,400–200,000 |
The disease is spread by contact with fresh water contaminated with the parasites. These parasites are released from infected freshwater snails. The disease is especially common among children in developing countries, as they are more likely to play in contaminated water. Schistosomiasis is also common among women, who can have greater exposure through daily chores that involve water like washing clothes and fetching water. Other high-risk groups include farmers, fishermen, and people using unclean water during daily living. It belongs to the group of helminth infections. Diagnosis is by finding eggs of the parasite in a person's urine or stool. It can also be confirmed by finding antibodies against the disease in the blood.
Methods of preventing the disease include improving access to clean water and reducing the number of snails. In areas where the disease is common, the medication praziquantel may be given once a year to the entire group. This is done to decrease the number of people infected, and consequently, the spread of the disease. Praziquantel is also the treatment recommended by the World Health Organization for those who are known to be infected.
Schistosomiasis affected about 236.6 million people worldwide in 2019. An estimated 4,400 to 200,000 people die from it each year. The disease is most commonly found in Africa, Asia, and South America. Around 700 million people, in more than 70 countries, live in areas where the disease is common. In tropical countries, schistosomiasis is second only to malaria among parasitic diseases with the greatest economic impact. Schistosomiasis is listed as a neglected tropical disease.