Leishmaniasis

Question 1

Classification:

Answer 1

Protozoa

Question 2

Indirect or direct:

Hosts:

Answer 2

Indirect life cycle

Humans are intermediate hosts

Sandflies are intermediate hosts

Question 3

Diagnosis:

Answer 3

Microscopy
- Different species are indistinguishable

Serology:
- antibody detection only useful in visceral leishmaniasis. Limited value in cutaneous form since most patients do not develop significant antibody response with the cutaneous form.

Molecular
- PCR can differentiate between species.

Question 4

Transmission and life cycle:

Answer 4

Transmitted through bite of female sandfly. Sandflies inject infective promastigotes. These are phagocytized by macrophages and other phagocytic cells.

Promastigotes transform in these cells into the tissue stage of the parasite: amastigotes.

Amastigotes multiply by binary fission and proceed to infect other mononuclear phagocytic cells.

The sandfly becomes infected again when taking a blood male and injesting amastigotes that again transform into promastigotes in the sandflies gut.