Seroprevalence and risk factors associated with exposure to Leishmania infantum in dogs, in an endemic Mediterranean region

Abstract

Canine leishmaniasis (CanL) is a zoonotic parasitic disease caused by Leishmania infantum in the Mediterranean area and transmitted by phlebotomine sand fly vectors. The domestic dog is the main reservoir host. The aim of this study was to assess the influence of different individual, environmental and spatial risk factors on the dog exposure to L. infantum and to estimate the seroprevalence among owned and kennel dogs, in the Lazio region (central Italy), where canine leishmaniasis is endemic. In the period 2010–2014, 13,292 sera from kennel and owned dogs were collected by official and private veterinarians. The presence of anti-Leishmania IgG was analysed by indirect fluorescent antibody test (IFAT), using a 1:80 titre cut-off. At the univariable analysis, CanL seropositivity was associated with sex, size, breed, coat length, living with other dogs and forest/semi-natural land cover. At the multivariable analysis, age, ownership and attitude were confirmed as risk factors, being more than 2 years old, owned, and hunting dogs at higher risk. Being a Maremma sheepdog was a protective factor. A true overall seroprevalence of 6.7% (95% CI: 6.2–7.2) was estimated in the whole population while 7.3% (95% CI: 6.8–7.8) was estimated in kennel dogs and 74.3% (95% CI: 70.8–77.6) in owned dogs. The role of kennels as a key component for CanL active and passive surveillance was also highlighted. This study confirmed the endemicity of CanL in the Lazio region and focused some factors that can influence the seropositivity of dogs in a Mediterranean region.

Seroprevalence and Risk Factors Associated with Canine Leishmaniasis in Egypt

“…In the present study, dogs older than two years were more likely to become infected. This finding was in accordance with those of previous studies, which confirmed that the risk of infection increased with the age of the dogs [20,31,32]. A popular explanation is that adult dogs remain outside for long periods and that increases their chance of contact with vectors [33][34][35][36], and that the immune response against latent infection in resistant dogs may develop in older dogs [37].…”

“…In order to facilitate and improve disease control, sensitive diagnostic tests that may be used in the field are becoming increasingly important. IFATs, ELISAs and direct agglutination tests (DATs) are the most widely used serological tests in CanL screening [14,20]. ELISA is a highly applicable technique that is characterised by high sensitivity, but its specificity depends on the antigen.…”

“…Serological examination is a useful tool to detect specific antibodies and to determine the spread of the disease, because a large proportion of dogs are asymptomatic [19]. Enzyme-linked immunosorbent assay (ELISA) and indirect fluorescent antibody tests (IFAT) are the most widely used serological methods [20]. ELISA shows potential as a sensitive tool for mass screening in epidemiological studies and is suited to field conditions [21,22].…”

Exposure to Major Vector-Borne Diseases in Dogs Subjected to Different Preventative Regimens in Endemic Areas of Italy

“…Dogs with circulating antibodies against L. infantum were found in almost all sites, with the exception of Site B. The rates detected in sites E and F fit with those of recent studies carried out in the same regions of central Italy [ 52 , 53 , 54 ]. The rates found in site C are not comparable with data from a recent study in which similar seroprevalence values were detected but with lower cut-off dilutions [ 55 ].…”

Feline Leishmaniosis: An Emerging Public Health Problem

“…Leishmaniosis is a disease caused by the infection of protozoan parasite Leishmania spp. and transmitted by sandflies of the family Psychodidae (genus Phlebotomus in the Mediterranean region) [ 1 , 2 , 3 , 4 ]. The World Health Organization (WHO) estimates between 700,000 and 1,000,000 new cases in humans annually.…”