Leishmaniasis is an example of a vector-borne disease, meaning that it is passed on from person to person by some biting insect or other carrier. A well-known example is the role of the mosquito in the spread of malaria. In the same way small blood feeding insects called sand flies pass on the Leishmania parasite. In humans this results in a range of symptoms, from self-curing skin ulcers to life threatening disease, depending on exactly which one of the 20 or so Leishmania species is involved. The relationship between the parasite and the sand fly is not a passive one, the parasites liveand multiply inside the gut of the sand fly for a few weeks before they are ready to be passed on. During this period the parasites have to cope with various threats including the possibility that they will be expelled from the gut along with undigested waste matter. To combat this threat the parasites attach to the wall of the gut. The purpose of this project is to investigate the mechanism of attachment, describe the parasite and sand fly molecules involved and understand how this interaction enables the parasite to be passedon and cause human disease.