The dog is the most important reservoir host, but cats, rodents, wild animals and humans can also be parasitized. In order to complete its cycle and be transmitted to vertebrate hosts, the parasite needs to mature in an arthropod, which therefore acts as a vector: the phlebotomist or sandfly. In fact, inside the intestine of the vector it is found in the form of promastigote and, having reached the infectious stage, it moves to the level of the buccal apparatus to be transmitted in the subsequent blood meal. Once promastigotes have been injected into the vertebrate host, the Leishmania continues its cycle becoming amastigote, an intracellular form replicating within white line cells such as macrophages.
The development of the disease, therefore of Leishmaniasis, depends on the immune factors of the parasitized organism, which lead to symptomatic manifestations over a period of months or years.
which is re-emerging in Europe and for which cases of infestation and disease have been increasing in recent years.
Infestation in humans occurs with the same mechanism as other vertebrates, ie through the blood meal of a Leishmania-carrying phlebotomist, but the symptoms that develop can be grouped into two broad categories: the cutaneous form and the visceral form.