Biharzia (scistosomiasis) is a disease caused by parasitic worms Schistosoma mansoni, Schistosoma haematobium and Schistosoma japonicum. The infestation with the parasite does not occur in the United States. However, the parasite leads to infection of approximately 200 million people worldwide.
How Is the Parasite Transmitted?
The infection develops once the skin comes in contact with contaminated fresh water that contains snails - the carriers of the parasite. Water becomes contaminated if one infected with the parasite urinates or defecates into the particular water mass. The eggs of the parasite then grow and develop inside the snails found in the water. Once the parasite is mature enough it leaves the snails and is able to penetrate the skin of people who wade, swim, bath or wash in the contaminated water. After several weeks the worm grows inside the blood vessels and some of the eggs travel to the bladder or intestine from where they are passed into the outside world.
Clinical Characteristics of Bilharzia
Days after a person becomes infected he/she may develop rash or his/her skin becomes itchy. The infection typically features with fever, chills and cough as well as muscle aches that develop 1-2 months after infestation. In the early phase of the infection a person may be totally asymptomatic.
Eggs of the parasite travel to the liver and are passed into the intestine and bladder. In rare cases eggs reach the brain and the spinal cord. In such cases one may develop seizures, paralysis and inflammation of the spinal cord. In case a person is repeatedly infected with the worm he/she is at a higher risk to develop serious damage to the liver, intestines, lungs and bladder. Generally all the symptoms of the parasitic infestation develop as a body's reaction to the eggs and not the worms themselves.
Bilharzia can be confirmed only after samples of urine or feces are taken from the infected person and the presence of the parasite confirmed. Furthermore, there is a specific blood test that may help in diagnosing the infection. In order to obtain accurate results the person must wait for 6-8 weeks after the exposure to the contaminated water before the test is performed.
How To Treat Bilharzia?
There are rather safe and effective medications that may eradicate the worm. They are administered for a day or two. The infection is also treated with a single dose of the drug praziquantel annually. The vaccine against the parasite does not exist but the researchers are trying to develop one.
With the vaccine the infection could be successfully prevented. There are specific plans and programs for villages in the world in which many people are infected with the disease.
Prevention is a highly effective method against the disease. Namely, it is essential to avoid swimming or wading in fresh water in countries where bilharzia occurs. Furthermore, one should drink only safe water. Bath water must be heated for 5 minutes at 150° F. Water that is stored in a tank for at least 48 hours is potentially safe for showering. And finally, vigorously towel drying after an accidental and very brief water exposure may be helpful in prevention against Schistosoma parasite from penetrating the skin.