Essai d’une étude épidémiologique sur la leishmaniose dans la région de la Kabylie.

Abstract

Leishmaniasis is a vector-borne disease caused by protozoan parasites of the genus Leishmania and transmitted by the bites of female sandflies. It affects both animals and humans. More than 23 species of Leishmania have been described, most of which are zoonotic. The most important Leishmania parasite affecting domestic animals is L.infantum. Dogs are considered as the main hosts of the infection. Leishmaniasis is common in the Mediterranean, South and Central America and Europe, it is a major zoonosis endemic in more than 88 countries, among them Algeria. Leishmania is a diphasic parasite that completes its life cycle in two hosts, a sandfly that hosts flagellate extracellular promastigotes and a mammal where forms of intracellular amastigotes parasites develop. The sandfly is active from April to October and especially at nightfall. The transmission of leishmaniasis in dogs is essentially vectorial but other modes of transmission exist such as venereal transmission during mating or pregnancy bitches that can transmit the parasite to their litter. Canine leishmaniasis is a multisystemic disease with a highly variable range of clinical manifestations. There are two types of leishmaniasis in dogs: a cutaneous or skin infection and a visceral or organic infection. The number and intensity of clinical signs are determined by a combination of factors involving the parasite strain, genetics and the immune status of the host. In this way, some dogs are able to control the infection for many years without the appearance of clinical signs. On the other hand, some infected dogs may show an acute course and severe disease, or a progressive course that leads inexorably to death, if proper management and therapy is not adopted. The diagnosis of canine leishmaniasis is often difficult because of its varied clinical table. The suspicion of this parasitosis in dogs is based on a good anamnesis and exhaustive memorialization and a clinical examination accompanied by further investigations. The detection of leishmanias depends on two main methods, direct and indirect. The direct method is based on parasitological, cytological and histological tests, and a rapid molecular biology technique called Polymerase Cain Reaction (PCR) which allows to obtain a complex and scarce sample of DNA in sufficient quantity. The indirect method, which is serological, is the most widely used in the diagnosis of leishmaniasis. The immunochromatography test is a qualitative, rapid and easy test unlike the Enzyme Linked Immunosorbent Assay (ELISA) and Indirect Immunofluorescent Antibody Test (IFAT) which are quantitative tests. Each test differs in sensitivity and specificity and each of these tests has its advantages and disadvantages. The treatment options are limited and the most recommended drugs used to treat canine leishmaniasis are meglumine antimoniate in injection form, combined with oral allopurinol in most cases, although these may lead to temporary or permanent remission of clinical signs, but none of them is able to eliminate infections. Since the dog is the main reservoir, so it is important to take some measures to protect ourselves and the dogs from the bites of infected sandflies through blood meals on infected dogs. For that the prevention of leishmaniasis is an essential approach, based on the control of the vector mosquito, combined with vaccination of dogs in environments with high risk of infestation.