Descripció del projecte
Zoonotic Visceral leishmaniasis (ZVL), caused by Leishmania donovani in Asia and Africa and by L. infantum in the Mediterranean Basin, the Middle East, Central Asia, South America, and Central America, is a life-threatening disease that affects ≈200,000–400,000 persons annually and causes an estimated ≈20,000–40,000 deaths per year. Although an increasing number of other mammalian hosts, including infected humans, have served as effective reservoirs by infecting phlebotomine sand fly vectors, dogs remain a pivotal indirect source in many situations where the transmission cycle of L. infantum occurs. The control of infection by Leishmania infantum in dogs is essential to stop the current spread of ZVL but this is a difficult assignment due to the following reasons:
– Many animals remain asymptomatic after infection, but, in some cases, are still capable of transmitting the parasite, as well as those who develop symptoms of canine leishmaniasis.
– Current chemotherapy reduces or eliminates clinical symptoms, but does not consistently achieve parasitological cure in dogs, and the epidemiological risk persists.
– The culling of seropositive dogs has not prevented the increasing number of human cases in countries where this has been practiced (Brazil)
– The use of topical insecticides and impregnated collars are costly and difficult to implement in a national control program.
In the absence of other successful strategies, the development of vaccines against canine leishmaniasis has been promoted as an important tool and a cost-effective strategy for controlling ZVL.
The aim of this project is the assessment of the efficacy and safety of an experimental canine Leishmania vaccine. This will be done through three clinical studies in two animal species, the target specie (dog) and in one experimental rodent model (hamster) and in two conditions, one study in the field under natural infection condition in a high endemic area and two studies in the laboratory, under an experimental infection. Animals will be followed up for clinical symptoms and parasite loads in the target tissues (primary efficacy variables). Serological and cellular immune response (CMI) assays against L. infantum will be also performed (secondary efficacy variables).
