Bilharzia Treatment

Bilharzia affects an estimated 200 million people around the world. More commonly known as schistosomiasis, bilharzia occurs when parasitic worms called Schistosoma mansoni, S. haematobium or S. japonicum enter people's bodies. The worms live on freshwater snails in tropical regions, and people become infected when they use or drink water in which the snails live. Bilharzia can lead to fatal organ damage when left untreated, but effective medications and preventive measures exist.

Praziquantel

• Praziquantel, which Bayer Healthcare sells under the brand name Biltricide, is the treatment of choice for bilharzia. Patients with mild or moderate bilharzia who take a one- or two-day course of praziquantel tablets dosed to deliver 20 to 25 milligrams per kilogram of body weight almost always recover completely. The medication kills the worms and worm eggs that cause bilharzia quickly while usually causing no side effects that differ from the symptoms of the infection. However, praziquantel works less well for people who have suffered from bilharzia for six months or more.

Oxamniquine

• Patients with bilharzia caused by S. mansoni who don't respond to praziquantel can usually benefit from taking the drug oxamniquine. Patients take 20 mg/kg of oxamniquine for three days. Similar to praziquantel, oxamniquine use produces few and mild side effects.

Metrifonate

• Metrifonate works as well as praziquantel against all forms of bilharzia. Doctors and public health workers generally do not administer metrifonate to patients, however, because patients must take three separate doses at 14-day intervals. Having patients follow this 42-day dosing regimen can be difficult, and metrifonate does not provide its full benefit if a patient misses a dose.

Corticosteroids

• Patients with severe bilharzia or with a case of the disease that involves the brain may take oral corticosteroids. These medications reduce swelling and suppress other strong immune system responses to the presence of worms and worm eggs in the body. The immune response produces most of the visible symptoms of bilharzia, such as rash, itchiness, fever and lymph node and liver swelling. Drugs in the oral corticosteroid class include prednisone, betamethasone (e.g., Celestone from Schering-Plough) and methylprednisolone (e.g., Medrol from Pfizer).

Prevention

• People living or traveling in southern or sub-Saharan Africa, the Nile River Valley in Egypt, China, southeast Asia, north-central South America, Iran, Iraq, Saudi Arabia, Yemen, the Dominican Republic, Antigua, Saint Lucia or most of the French Caribbean need to protect themselves against bilharzia. In these areas, people must avoid swimming, wading or bathing in rivers or lakes; drink bottled or boiled water; bathe using water that has been heated to at least 150 degrees Fahrenheit for at least five minutes; and dry themselves immediately and thoroughly with a clean, dry towel after getting fresh water on their skin.