Viral, Protozoan, and Helminthic Diseases of the Cardiovascular and Lymphatic Systems

Viral, Protozoan, and Helminthic Diseases of the Cardiovascular and Lymphatic Systems Koch’s postulates are guidelines for determining that a specific microorganism causes a specific disease. Koch’s postulates are as follows: 1. The same pathogen must be present in every case of the disease. 2. The pathogen must be isolated from the diseased host and grown in pure culture. 3. The pathogen from the pure culture media must cause the disease when it is inoculated into a …

…from the snail in a form called cercaria. These can then penetrate the skin of a swimming or wading human. Then, the microbes are carried by the bloodstream to either the liver or urinary bladder. The cercaria matures into adult form, and a male and female produce ova. The ova can cause tissue damage called granulomas. Adult worms are unaffected by the human immune system. Schistosomiasis occurs in Asia, Africa, South America, and the Caribbean.