Schistosoma bovis

Schistosoma bovis is a two-host blood fluke, that causes intestinal schistosomiasis in ruminants in North Africa, Mediterranean Europe and the Middle East. S bovis is mostly transmitted by Bulinus freshwater snail species. It is one of nine haematobium group species and exists in the same geographical areas as Schistosoma haematobium, with which it can hybridise. S. bovis-S. haematobium hybrids can infect humans, and have been reported in West African countries, namely Senegal, and during a 2013 outbreak on Corsica. Schistosoma bovis is a digenetic, two-host blood fluke in cattle. It is one of nine Schistosoma species that share a similar lifecycle in the mammals they infect, called the haematobium group of schistosomes. Hybrids between S. bovis and the human schistosome, Schistosoma haematobium were first described in 2009 in Northern Senegalese children, and to a lesser degree hybrids between S. bovis and cattle schistosome S. curassoni found only in cattle. S. bovis / S. haematobium hybrids were also found during the 2013 outbreak traced to the Cavu river on Corsica.As a hybrid increases the host range of the parent species, they affect transmission, and as is known from other schistosome hybrid pairings, morbidity and drug susceptibility, so they are epidemiologically important. Schistosoma bovis infects two hosts, namely ruminants (cattle, goats, sheep, horses, camels and pigs) and freshwater snails (Bulinus sp. and Planorbarius sp.).:392 In water, its free swimming infective larval cercariae can burrow into the skin of its definite host, the ruminant, upon contact. The cercariae enter the host's blood stream, and travel to the liver to mature into adult flukes. Adult flukes can coat themselves with host antigen thus avoiding detection by the host immune system. After a period of about three weeks the young flukes migrate to the mesenteric veins of the gut to copulate. The female fluke lays eggs, which migrate into the lumen of the gut and leave the host upon defecation. In fresh water, the eggs hatch, forming free swimming miracidia. Miracidia penetrate into the intermediate host, the freshwater snails of the Bulinus spp., (e.g. B. globosus, B. forskalii, B. nyassanus and B. truncatus), except in Spain,:20 Portugal and Marocco, where Planorbarius metidjensis can transmit. Inside the snail, the miracidium sheds its epithelium, and develops into a mother sporocyst. After two weeks the mother begins forming daughter sporocysts. One month -or more with cooler ambient temperatures- after a miracidium has penetrated into the snail, hundreds to thousands of cercariae of the same sex begin to be released through special areas of the sporocyst wall.:30 The cercariae cycle from the top of the water to the bottom in search of a host. They can enter the host epithelium within minutes.:34 S. bovis infects snails in Africa north of the equator, Europe (Sardinia, Corsica, Spain) and the Middle East as far as Iraq.:20S. bovis - S. haematobium hybrids have been reported in Senegal, and as of 2013 in Corsica. Animals may have diarrhea mixed with blood or mucous, become dehydrated, pale, lose weight, developing a rough hair coat, show decreased milk production, reduced fertility and draft power, all of which have economic importance to the livestock owner:6