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Among the 20 or so Leishmania spp. described as pathogenic for humans, those of the Leishmania donovani complex are the exclusive causative agents of systemic and fatal visceral leishmaniasis. Although well studied, the complex is taxonomically controversial, which hampers clinical and epidemiological research. In this work, we analysed 56 Leishmania strains previously identified as L. donovani, Leishmania archibaldi or Leishmania infantum, isolated from humans, dogs and sandfly vectors throughout their distribution area. The strains were submitted to biochemical and genetic analyses and the resulting data were compared for congruence. Our results show: i) a partial concordance between biochemical and genetic-based data, ii) very limited genetic variability within the L. donovani complex, iii) footprints of frequent genetic exchange along an east-west gradient, marked by a widespread diffusion of alleles across the geographical range, and iv) a large-scale geographical spreading of a few genotypes. From a taxonomic point of view, considering the absence of relevant terminology in existing classes, the L. donovani complex could be treated as a single entity., (Copyright © 2020 Australian Society for Parasitology. Published by Elsevier Ltd. All rights reserved.)

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., Competing Interests: Declaration of Competing Interest The authors declare no competing interests., (Copyright © 2020 Elsevier B.V. All rights reserved.)

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., (Copyright © 2018 The Authors. Published by Elsevier B.V. All rights reserved.)

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., (Copyright © 2013 Elsevier B.V. All rights reserved.)

Molecular methods have been proposed as an alternative tool for the diagnosis of visceral leishmaniasis (VL), but no data are available regarding use for monitoring clinical outcome. A prospective cohort study of human immunodeficiency virus-(HIV) and VL-coinfected patients was conducted in a university-affiliated hospital in Barcelona, Spain. Leishmania parasite load was monitored using a real-time polymerase chain reaction (PCR) at baseline and every 3 months. Cutoff values for PCR were determined using receiver operating characteristic (ROC) curves. Overall, 37 episodes were analyzed, and 25 of these episodes were considered as relapsing episodes. A significant decrease of parasite load measured 3 months after treatment could predict the clinical evolution of VL. A parasite load over 0.9 parasites/mL measured 12 months after treatment could predicts relapse with a sensitivity of 100% and a specificity of 90.9%. Monitoring parasite load by an ultrasensitive quantitative Leishmania PCR is useful to predict the risk of relapse after a VL episode in HIV-infected patients.

A Western blot (WB) method using a lysate from Trypanosoma cruzi (Maracay strain) epimastigotes was evaluated. Serum samples from 37 patients with confirmed Chagas disease (cohort I), 27 Spanish patients with visceral leishmaniasis caused by Leishmania infantum (cohort II), and 28 Colombian patients with cutaneous leishmaniasis caused by L. panamensis and negative serology for Chagas disease (cohort III) were tested. The negative controls were 55 healthy seronegative subjects for T. cruzi and Leishmania; 28 of the negative controls were from a region endemic for Chagas disease and Leishmania (cohort IV), and 27 of the negative controls were from a non-endemic area for Leishmania and T. cruzi (cohort V). A homogeneous standard band pattern consisting of six antigenic bands corresponding to 28, 32, 38, 39, 40, and 48 kDa was recognized simultaneously for all Chagasic patients' sera. Sera from Leishmania-infected patients showed a heterogeneous band pattern that was easily differentiated from the pattern of patients with Chagas disease. WB with T. cruzi epimastigote antigen is an efficient method for diagnosis and may be used as an alternative to confirm T. cruzi and detect cross-reactivity with Leishmania.