Parasitic protozoan promastigote, SEM

Parasitic promastigotes that cause leishmaniosis in humans (Leishmania braziliensis), coloured scanning electron micrograph (SEM). This tropical protozoan disease is transmitted by bites from infected sand flies (insect vector). The parasites are ingested by the insect vector during a blood meal from a mammal or human. The parasites in humans are found within macrophages in the amastigote form. In the blood stream they transform into the promastigote form. Promastigotes multiple by longitudinal fission in the gut of the insect. Leishmaniosis occurs in two forms: cutaneous which affects the skin and mucous membranes, usually giving rise to an ulcer at the site of the insect bite. Some patients develop a more destructive and progressive infection in mucosal tissue. The more serious kala-azar causes fever and liver damage, and it can be fatal. Magnification: x2,200 when shortest axis printed at 25 millimetres.