Babesia bovis is a protozoan parasite of cattle.

A proto- what?- A protozoan is a single celled eukaryotic organism. It is important to note that they are not bacteria. 

- Many protozoan species are free-living and exist everywhere on Earth.

- However, some species of protozoan are the most deadly parasites of man and beast. 

- The disease malaria is caused by species that belong to the Plasmodium group. Malaria kills 660,000 people every year.

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Picture: Babesia sp. life cycle. 

- Sporozoite-carrying ticks infect a mammalian host while taking a blood meal. 

- Sporozoites enter erythrocytes (RBCs) and reproduce through asynchronous binary fission, resulting in two, or sometimes four, merozoites. 

- Once present in a reservoir host (for B. microti , the reservoir is the white-footed mouse), parasites will develop into male and female gametes. When an ixodide tick feeds upon a competent reservoir, blood-stage gametes are introduced into the gut, where these gametes are fertilized to become zygotes. 

- Zygotes enter the tick salivary gland and undergo a sporogonic cycle, forming infectious sporozoites. 

- Humans are generally an intermediate host of Babesia species, although blood transfusion transmission does occur. 

- Dogs are intermediate hosts, much like humans, although they may have a domestic reservoir role in the human transmission of the newly emerging species Babesia conradae