Parasite Pursuit: Sand fly coughs up leishmania protozoan’s secrets of proliferation

Leishmania, a tropical parasite carried by sand flies, spreads prolifically to mammals by forcing the flies to regurgitate as they bite their prey, a new study finds.

While still in the sand fly, the parasite secretes—and then multiplies in—a gel that obstructs the fly’s throat. When the fly bites a person or another mammal to feed on blood, the insect is forced to expel the parasite-laden blob of gel into the victim’s bloodstream, the researchers report in the July 22 Nature.