Haematozoa

Blood parasites that have been studied were found to be transmitted by hematophagous (bloodsucking) dipteran (insect) vectors that have life stages in both aquatic and aerial environments.

[2] Theileria is a haematozoan parasite, mainly found in coastal areas, that is transmitted by Haemaphysalis longicornis ticks that emerged from the Eastern hemisphere.

[4] Cases of Theileria orientalis were recently found in the Eastern United States in 2017 where cattle in Virginia presented symptoms concurrent with the parasite.

The Theileria orientalis parasite, like other haematozoa, infect erythrocytes, causing chronic anemia resulting in illness and death of cattle.

Identification of Theileria orientalis is achieved by the sequencing of blood samples to identify two key features of the parasite, a small ribosomal subunit and a major piroplasm surface protein.

Avian species serve adequate hosts that transmit haematozoa during migratory periods, which increases fitness of the parasite.