Leishmanioses are a group of zoonotic diseases transmitted to humans and animals by the bite of phlebotomine sand flies. The diseases are named after Sir William Boog Leishman, Director General Army Medical Services 1923-1926. Leishmanioses are caused by intracellular parasitic protozoans. Worldwide, they are one of the most important vector-borne diseases.
Two types of leishmanioses can broadly be distinguished: 1. Zoonotic leishmanioses, in which the reservoir hosts are wild animals, commensals or domestic animals and 2. Anthroponotic leishmanioses, in which the reservoir is man. Clinical manifestation of the disease depends on the type of pathogen and thus the type of leishmaniosis. It can be a life-threatening systemic infection (visceral form), go along with chronic skin sores (cutaneous form), or show dreaded metastatic complications, causing facial disfigurement (mucosal form).
In the veterinary field of all domestic animals the dog is the main reservoir for Leishmania infantum that causes a visceral human leishmaniosis form. It is also the domestic animal most severely affected by the parasite itself. Depending on the part of the world, the importance of diseased animals as a veterinary subject differs. In countries endemic for leishmaniosis, veterinary treatment is often not affordable, whereas in areas as the Mediterranean basin diseased dogs represent a typical veterinary patient.
Due to their importance, the epidemiology of leishmanioses has been studied extensively during the last years. General Aspects covers different features, including
- Dogs as a reservoir
- Asymptomatic carriers
- Infections in non-endemic countries
- Non-vectorial transmission
Approximately 350 million individuals (~ 1/18 of the world population) in 88 countries are at risk worldwide and 12 million people are affected by leishmaniosis, with ~ 1-1.5 million new cases of cutaneous and 0.5 million new cases of visceral leishmaniosis annually. Urbanization due to ecological, demographic and environmental changes appears to be one of the major worldwide risk factors for leishmaniosis and largely contributes to the persistence of the burden of the disease, especially in anthroponotic foci.
- Fact Sheet: Leishmaniosis (Download)