SCHISTOSOMIASISWhat is schistosomiasis?Schistosomiasis, also known as bilharzia, is a disease caused by parasitic worms. Infection withSchistosoma mansoni, S. haematobium, andS. japonicumcauses illness in humans; less commonly,S. mekongiandS. intercalatumcan cause disease. Although the worms that cause schistosomiasis are not found in the United States, more than 200 million people are infected worldwide.How can I get schistosomiasis?Infection occurs when your skin comes in contact with contaminated freshwater in which certain types of snails that carry schistosomes are living.Freshwater becomes contaminated bySchistosomaeggs when infected people urinate or defecate in the water. The eggs hatch, and if certain types of freshwater snails are present in the water, the parasites develop and multiply inside the snails. The parasite leaves the snail and enters the water where it can survive for about 48 hours.Schistosomaparasites can penetrate the skin of persons who are wading, swimming, bathing, or washing in contaminated water. Within several weeks, parasite mature into adult worms, residing in the blood vessels of the body where the females produce eggs. Some of the eggs travel to the bladder or intestine and are passed into the urine or stool.What are the signs and symptoms of schistosomiasis?Within days after becoming infected, you may develop a rash or itchy skin. Fever, chills, cough, and muscle aches can begin within 1-2 months of infection. Most people have no symptoms at this early phase of infection.When adult worms are present, the eggs that are produced usually travel to the intestine, liver or bladder, causing inflammation or scarring. Children who are repeatedly infected can develop anemia, malnutrition, and learning difficulties. After years of infection, the parasite can also damage the liver, intestine, lungs, and bladder. Rarely, eggs are found in the brain or spinal cord and can cause seizures, paralysis, or spinal cord inflammation.Symptoms of schistosomiasis are caused by the body's reaction to the eggs produced by worms, not by the worms themselves.What should I do if I think I have schistosomiasis?See your health care provider. If you have traveled to countries where schistosomiasis is found and had contact with freshwater, describe in detail where and for how long you traveled. Explain that you may have been exposed to contaminated water.How is schistosomiasis diagnosed?Your health care provider may ask you to provide stool or urine samples to see if you have the parasite. A blood sample can also be tested for evidence of infection. For accurate results, you must wait 6-8 weeks after your last exposure to contaminated water before the blood sample is taken.

What is the treatment for schistosomiasis?Safe and effective drugs are available for the treatment of schistosomiasis. Praziquantel is the recommended treatment drug. See your doctor for appropriate diagnosis and treatment.Am I at risk?If you live in or travel to areas where schistosomiasis occurs and your skin comes in contact with freshwater from canals, rivers, streams, ponds, or lakes, you are at risk of getting schistosomiasis.In what areas of the world does schistosomiasis occur? Africa: all freshwater in southern and sub-Saharan Africaincluding the great lakes and rivers as well as smaller bodies of waterare at risk for schistosomiasis transmission. Transmission also occurs in the Mahgreb region of North Africa and the Nile River valley in Egypt and Sudan. South America: Brazil, Suriname, Venezuela Caribbean: Dominican Republic, Guadeloupe, Martinique, Saint Lucia (risk in Caribbean is low) The Middle East: Iran, Iraq, Saudi Arabia, Yemen Southern China Parts of Southeast Asia and the Philippines, LaosHow can I prevent schistosomiasis? Avoid swimming or wading in freshwater when you are in countries in which schistosomiasis occurs. Swimming in the ocean and in chlorinated swimming pools is safe. Drink safe water. Although schistosomiasis is not transmitted by swallowing contaminated water, if your mouth or lips come in contact with water containing the parasites, you could become infected. Because water coming directly from canals, lakes, rivers, streams, or springs may be contaminated with a variety of infectious organisms, you should either boil water for 1 minute or filter water before drinking it. Boiling water for at least 1 minute will kill any harmful parasites, bacteria, or viruses present. Iodine treatment aloneWILL NOT GUARANTEEthat water is safe and free of all parasites. Bath water should be heated to a rolling boil for at least 1 minute. Water held in a storage tank for at least 1-2 days should be safe for bathing. Vigorous towel drying after an accidental, very brief water exposure may help to prevent theSchistosomaparasite from penetrating the skin. You shouldNOTrely on vigorous towel drying to prevent schistosomiasis.

FILARIASISWhat is lymphatic filariasis?Lymphatic filariasis is a parasitic disease caused by microscopic, thread-like worms. The adult worms only live in the human lymph system. The lymph system maintains the body's fluid balance and fights infections.Lymphatic filariasis affects over 120 million people in 80 countries throughout the tropics and sub-tropics of Asia, Africa, the Western Pacific, and parts of the Caribbean and South America. You cannot get infected with the worms in the United States.How is lymphatic filariasis spread?The disease spreads from person to person by mosquito bites. When a mosquito bites a person who has lymphatic filariasis, microscopic worms circulating in the person's blood enter and infect the mosquito. People get lymphatic filariasis from the bite of an infected mosquito. The microscopic worms pass from the mosquito through the skin, and travel to the lymph vessels. In the lymph vessels they grow into adults. An adult worm lives for about 5-7 years. The adult worms mate and release millions of microscopic worms, called microfilariae, into the blood. People with the worms in their blood can give the infection to others through mosquitoes.Who is at risk for infection?Repeated mosquito bites over several months to years are needed to get lymphatic filariasis. People living for a long time in tropical or sub-tropical areas where the disease is common are at the greatest risk for infection. Short-term tourists have a very low risk. An infection will show up on a blood test.What are the signs and symptoms of lymphatic filariasis?Most infected people are asymptomatic and will never develop clinical symptoms, despite the fact that the parasite damages the lymph system. A small percentage of persons will develop lymphedema. This is caused by improper functioning of the lymph system that results in fluid collection and swelling. This mostly affects the legs, but can also occur in the arms, breasts, and genitalia. Most people develop these clinical manifestations years after being infected.The swelling and the decreased function of the lymph system make it difficult for the body to fight germs and infections. Affected persons will have more bacterial infections in the skin and lymph system. This causes hardening and thickening of the skin, which is called elephantiasis. Many of these bacterial infections can be prevented with appropriate skin hygiene.Men can develop hydrocele or swelling of the scrotum due to infection with one of the parasites that causes LF specificallyW. bancrofti.Filarial infection can also cause pulmonary tropical eosinophilia syndrome. This syndrome is typically found in infected persons in Asia. Clinical manifestations of pulmonary tropical eosinophilia syndrome include cough, shortness of breath, and wheezing. The eosinophilia is often accompanied by high levels of IgE (Immunoglobulin E) and antifilarial antibodies.

How is lymphatic filariasis diagnosed?The standard method for diagnosing active infection is the identification of microfilariae by microscopic examination. This is not always feasible because in most parts of the world, microfilariae are nocturnally periodic, which means that they only circulate in the blood at night. For this reason, the blood collection has to be done at night to coincide with the appearance of the microfilariae.Serologic techniques provide an alternative to microscopic detection of microfilariae for the diagnosis of lymphatic filariasis. Because lymphedema may develop many years after infection, lab tests are often negative with these patients.How can I prevent infection?Avoiding mosquito bites is the best form of prevention. The mosquitoes that carry the microscopic worms usually bite between the hours of dusk and dawn. If you live in or travel to an area with lymphatic filariasis: Sleep under a mosquito net. Wear long sleeves and trousers. Use mosquito repellent on exposed skin between dusk and dawn

What is the treatment for lymphatic filariasis?People infected with adult worms can take a yearly dose of medicine, called diethylcarbamazine (DEC), that kills the microscopic worms circulating in the blood. While this drug does not kill all of the adult worms, it does prevent infected people from giving the disease to someone else.Lymphedema and elephantiasis are not indications for DEC treatment because most people with lymphedema are not actively infected with the filarial parasite. Physicians can obtain DEC from CDC after lab results confirm infection.Even after the adult worms die, lymphedema can develop. You can ask your physician for a referral to see a lymphedema therapist for specialized care. Prevent the lymphedema from getting worse by following several basic principles: Carefully wash the swollen area with soap and water every day. Elevate and exercise the swollen arm or leg to move the fluid and improve the lymph flow. Disinfect any wounds. Use antibacterial or antifungal cream if necessary.