MSD Manual

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Life Cycle of Trypanosoma
Life Cycle of Trypanosoma
    • 1. When an infected kissing (Triatominae) bug bites a person, it deposits feces that contain the protozoa.

    • 2. The protozoa enter through the bite wound or through mucosal membranes, such as the clear membrane that covers the eye (conjunctiva).

    • 3. The protozoa then change forms and multiply.

    • 4. They change forms again, enter the bloodstream, and travel to other tissues. There, they change into a form that causes symptoms.

    • 5. When another kissing bug bites an infected person (or animal), it becomes infected.

    • 6–7. Inside the bug, the protozoa change forms and multiply.

    • 8. In the lower part of the bug's gut (hindgut), they change to a form that can infect people and animals. They are then excreted in the bug's feces.

Image from the Centers for Disease Control and Prevention Image Library.