This was the first demonstration that an arthropod could act as a disease vector to transmit an infectious agent to a vertebrate host.In 1957, the first human case was documented in a splenectomized Croatian herdsman. The agent was B. divergens. In 1969, the first case was reported in an immunocompetent individual on Nantucket Island. The agent was B. microti, and the vector was the tick I. scapularis. Equine babesiosis (caused by the protozoan Theileria equi) is also known as piroplasmosis (from the Latin piro, meaning pear + Greek plasma, a thing formed). Other animals
Veterinary treatment of babesiosis does not normally use antibiotics. In livestock and  animals, diminazen (Berenil), imidocarb, or trypan blue would be the drugs of choice for treatment of B. canis rossi (dogs in Africa), B. bovis, and B. bigemina (cattle in Southern Africa). In acute cases in cattle, blood transfusion may be carried out. A vaccine is effective against B. canis canis (dogs in the Mediterranean region), but is ineffective against B. c. rossi. B. imitans causes a mild form of the disease that frequently resolves without treatment (dogs in Southeast Asia). References
External links

Center for Global Health (2019-06-25). "Babesiosis". Parasites and Health, DPDx—Laboratory Identification of Parasites of Public Health Concern. Centers for Disease Control & Prevention. Archived from the original on 2013-03-07. Retrieved 2003-10-07. Public domain source from which the first version of this article was derived. Krause, Peter J;  et al. (27 January 2021).
Most often, PCR testing is used in conjunction with blood film examination and possibly serologic testing.Other laboratory findings include decreased numbers of red blood cells and platelets on complete blood count.In animals, babesiosis is suspected by observation of clinical signs (hemoglobinuria and anemia) in animals in endemic areas. Diagnosis is confirmed by observation of merozoites on thin film blood smear examined at maximum magnification under oil using Romonovski stains (methylene blue and eosin). This is a routine part of the veterinary examination of dogs and ruminants in regions where babesiosis is endemic.Babesia canis and B. bigemina are "large Babesia species" that form paired merozoites in the erythrocytes, commonly described as resembling "two pears hanging together", rather than the "Maltese cross" of the "small Babesia species". Their merozoites are around twice the size of small ones.Cerebral babesiosis is suspected in vivo when neurological signs (often severe) are seen in cattle that are positive for B. bovis on blood smear, but this has yet to be proven scientifically. Outspoken red discoloration of the grey matter post mortem further strengthens suspicion of cerebral babesiosis. Diagnosis is confirmed post mortem by observation of Babesia-infected erythrocytes sludged in the cerebral cortical capillaries in a brain smear. Treatment
Treatment of asymptomatic carriers should be considered if parasites are still detected after 3 months. In mild-to-moderate babesiosis, the treatment of choice is a combination of atovaquone and azithromycin. This regimen is preferred to clindamycin and quinine because it has fewer side effects.