Specificity of this assay for detecting schistosome infection is 99%. Serologic testing looks for the presence of antibodies against the adult schistosome in the blood. The first hosts of the schistosome were birds. The Kato technique is now most commonly used for detecting schistosome eggs. "Gigantobilharzia lawayi", a schistosome (or blood fluke) may be carried in the capillaries. The clinically defining characteristic of most schistosome species are their eggs' size and shape. In response to infection, the hosts' antibodies bind to the tegument of the schistosome. Schistosomes have four superoxide dismutases, and levels of these proteins increase as the schistosome grows. The schistosome can also take on host proteins. In 2000, the first BAC library of Schistosome was constructed. The schistosome worms make two tetraspanins&colon; TSP-1 and TSP-2. Historically, antimonials and trichlorphon were tested against visceral Schistosome infection in cattle. After the discoverer, the infection (generally including all schistosome infections) was called bilharzia or bilharziasis. The female schistosome is heterogametic, or ZW, and the male is homogametic, or ZZ. Rotifers ("Rotaria rotatoria") produce a chemical, Schistosome Paralysis Factor, suppressing cercaria swimming and reducing infections.