Schistosomiasis is a parasitic disease, which is contracted by skin contact with contaminated freshwater in which certain schistosomiasis carrying snails live. Schistosomiasis is not found in the United States. However, according to the Center for Disease Control (CDC), more than 200 million people are infected worldwide.
Freshwater becomes contaminated when infected people urinate or defecate in the water. The eggs, which are in the human waste, hatch and the parasites develop in a certain type of snail. The parasite leaves the host snail and enters the water, where it can survive for 48 hours.
Wading, swimming, bathing or washing in contaminated water can result in contact with and penetration of the schistosomiasis parasite. Within several weeks, the parasites grow inside the human's circulatory system and produce eggs. Some of the eggs migrate to the bladder or intestines and are excreted into urine or stool.
All bodies of freshwater in southern and sub-Saharan Africa are considered to be at risk for schistosomiasis transmission. Incidence occurs in the Nile River Valley in Egypt. The countries of Brazil, Suriname, and Venezuela in South America as well as the Caribbean countries of Antigua, Dominican Republic, Guadeloupe, Martinique, and Montserrat are areas of risk. The island of St. Lucia is a low risk area. This parasitic disease occurs in Iran, Iraq, Saudi Arabia, and Yemen. Southern China, the Philippines, Laos, Cambodia, central Indonesia, and the Mekong delta have occurrences of schistosomiasis.
Inhabitants of or travelers to these areas, whose skin has come in contact with freshwater either from canals, rivers, streams, or lakes are at risk. A rash or itchy skin may develop within days after being infected. Most people are without symptoms during the early phase of the infection. Fever, chills, cough, and muscle aches can appear within one to two months.
The eggs travel to the liver and into the intestines or bladder causing inflammation and scarring. Damage to the liver, intestines, lungs, and bladder is the result of repeated infections.