RESUMEN
Dog vaccination is considered an effective way of reducing Leishmania infantum infection incidence in the canine population, as well as its transmission to humans. However, the use of partially effective vaccines can have the detrimental effect of "masking" vaccinated asymptomatic carriers, capable of harbouring the parasite and transmitting it to naïve individuals. After eight years on the European market, few studies have been released on CaniLeish® vaccine safety and efficacy. The present study, a one-year randomized CaniLeish® vaccine field trial, was performed in a canine leishmaniosis endemic area and included animals selected from a native dog population (n = 168). No severe adverse reactions were observed in vaccinated dogs (n = 85). Cases of active L. infantum infection were detected by serological, molecular and clinical follow-up of dogs. One-year post-vaccination, no differences in number or severity of L. infantum active infections were observed between study groups (n = 4 in each group). Vaccine-induced cellular immunity, assessed through interferon-γ quantification, showed significantly higher levels of this cytokine one-month post-vaccination in the vaccine group (p < 0.001), but no differences were observed after nine months between trial groups (p = 0.078). These results fail to support the reported CaniLeish® efficacy in the prevention of active L. infantum infection in dogs from endemic areas and naturally exposed to the parasite.
Asunto(s)
Enfermedades de los Perros/prevención & control , Leishmania infantum/inmunología , Vacunas contra la Leishmaniasis/inmunología , Leishmaniasis Visceral/veterinaria , Vacunación/veterinaria , Animales , Enfermedades de los Perros/epidemiología , Perros , Femenino , Interferón gamma/sangre , Vacunas contra la Leishmaniasis/efectos adversos , Leishmaniasis Visceral/epidemiología , Leishmaniasis Visceral/prevención & control , MasculinoRESUMEN
The Mediterranean basin is an endemic region for canine leishmaniosis (CanL), where it represents a major veterinary problem and raises human health concerns. However, the distribution of the disease is heterogeneous and not all countries and locations have been equally studied and characterized. This work describes the situation of CanL in Girona province (Catalonia, Spain), for which no data has been previously reported, and presents a relevant study to exemplify other areas with similar characteristics across the region. Four cross-sectional seroprevalence surveys were performed from 2012 to 2016 throughout the province, including 36 sampling stations in 26 localities and a total of 593 dogs. For each animal, individual and location variables were also collected. Additionally, each dog owner answered a questionnaire about their knowledge of CanL and preventive methods used. Blood samples were analysed by an in-house ELISA and a mixed logistic regression model was used to assess the relationship between pre-determined variables and dog seropositivity. A Spearman's correlation was used to assess the association between dog owners' perceived risk of CanL and Leishmania infantum seropositivity in dogs at a given location. The overall true seroprevalence estimated for Girona province was 19.5% (95%CI: 15.5-23.5), of which only 6.8% (10/146) were considered symptomatic. Age of the dog [OR = 1.21 (95%CI: 1.11-1.31); p < 0.001] and altitude [OR = 0.02 (95%CI: 0.001-0.19); p = 0.001] were identified as risk factors for the infection. The results obtained in this study are expected to aid in the implementation of directed control programmes in CanL endemic areas throughout Europe, as well as to provide suitable data for the design of better risk assessment maps of the disease.
Asunto(s)
Enfermedades de los Perros/epidemiología , Leishmania infantum , Leishmaniasis Visceral/veterinaria , Factores de Edad , Altitud , Animales , Infecciones Asintomáticas/epidemiología , Enfermedades de los Perros/etiología , Enfermedades de los Perros/parasitología , Enfermedades de los Perros/prevención & control , Perros , Femenino , Leishmaniasis Visceral/epidemiología , Leishmaniasis Visceral/etiología , Leishmaniasis Visceral/parasitología , Masculino , Factores de Riesgo , Estudios Seroepidemiológicos , España/epidemiologíaRESUMEN
Leishmaniosis is present in the Mediterranean region of Europe, where Leishmania infantum is responsible for the disease, dogs are the main reservoir, and sand flies of the Phlebotomus genus, subgenus Larroussius, are proven vectors. Some areas, including Minorca in the Balearic Islands, are considered free of the disease, despite the presence of vectors. However, in the context of the current expansion of canine leishmaniosis in parts of Europe, an epidemiological study using a veterinary questionnaire was carried out to establish the current situation of the disease in the Balearic Islands. While 50% of veterinarians thought that the incidence of canine leishmaniosis had not changed over time, 26.2% perceived an increasing trend, mainly those from Minorca, where most of the veterinarians polled (88.1%) considered the new diagnosed cases as autochthonous. A cross-sectional serological study performed in this island gave a seroprevalence rate of 24%. Seroprevalence among animals of local origin and with no history of movements to endemic areas was 31%. The presence of autochthonous canine leishmaniosis in Minorca was not correlated with an increase in vector density. The environmental and climatic factors that influenced the distribution and density of Phlebotomus perniciosus on the island and the possible causes of the apparent emergence of canine leishmaniosis in Minorca are discussed.