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How do sand flies spread leishmaniasis?
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parasitic disease
Trypanosoma brucei in a blood smear (Giemsa-stained light photomicrograph).
Leishmaniasis is transmitted to humans through the bite of an infected, bloodsucking sand fly from the genera Phlebotomus or Lutzomyia.12
The transmission process follows these steps:
- Ingestion: When a sand fly feeds on an infected vertebrate, it ingests cells containing the parasite in its round, nonmotile form, known as an amastigote.12
- Development: Inside the fly's digestive tract, these parasites transform into an elongated, motile, flagellated form called a promastigote (or leptomonad).12
- Multiplication: The promastigotes multiply within the fly's gut and eventually migrate to its mouthparts.12
- Transmission: During the sand fly's next blood meal, the parasites are introduced into the wound created by the fly's bite, thereby initiating a new infection in the vertebrate host.12
Preventing the spread of this parasitic disease primarily involves controlling sand fly populations.1