Schistosomiasis.

Schistosomiasis is a parasitic infection caused by flatworms (trematodes). It is second only to malaria in public health significance, with over 200 million people infected worldwide, leading to severe consequences in 20 million persons and 100,000 deaths, annually. There are four species that cause intestinal schistosomiasis: Schistosoma mansoni; Schistosoma japonicum, Schistosoma mekongi, and Schistosoma intercalatum. Schistosoma haematobium causes urinary schistosomias, and is endemic in Africa and the Middle East, with the greatest prevalence in poor rural areas. Fibrotic changes in the urinary tract can lead to hydroureter, hydronephrosis, bacterial urinary infections, and ultimately, kidney disease or eventually bladder cancer. A rare lesion can also arise in patients infected with Schistosomiasis haematobium, resulting in squamous and adenosquamous prostate cancers. Imported diseases, such as schistosomiasis, are entering the United States through immigration via illegal aliens, refugees, and travelers. Schistosomiasis is a neglected tropical disease, and its global health impact is grossly underestimated.