Babesia

Babesia, also called Nuttallia, is an apicomplexan parasite that infects red blood cells and is transmitted by ticks. Originally discovered by the Romanian bacteriologist Victor Babeș in 1888, over 100 species of Babesia have since been identified. Babesia comprises more than 100 species of tick-borne parasites that infect erythrocytes (red blood cells) in many vertebrate hosts. Babesia species infect livestock worldwide, wild and domestic vertebrate animals, and occasionally humans, where they cause the disease babesiosis. In the United States, B. microti is the most common strain of the few which have been documented to cause disease in humans. Babesia is a protozoan parasite found to infect vertebrate animals, mostly livestock mammals and birds, but also occasionally humans. Common names of the disease that Babesia microti causes are Texas cattle fever, redwater fever, tick fever, and Nantucket fever. The disease it causes in humans, babesiosis, is also called piroplasmosis. Babesia microti, however, is not part of the genus Babesia. Due to historical misclassifications, the protozoan has been labeled with many names, including Nuttallia, and was renamed from Babesia microti to Theileria microti based on evidence from 2006. Its genetic sequence, published in 2012, shows that the species belongs to neither Babesia nor Theileria, but instead to a separate genus. Another "western" group is also separate from core Babesia. The avian Babesia species are characterized as having ring and amoeboid forms, and fan-shaped or cruciform (cross-shaped) tetrad schizonts. Developing parasites have only been reported in red blood cells. For centuries, the animal disease was known to be a serious illness for wild and domesticated animals, especially cattle. In 1888, Victor Babeș first identified the causative agent in Romania and believed it to be due to the bacterium he named Haematococcus bovis. He documented the disease by describing signs of a severe hemolytic illness seen uniquely in cattle and sheep.