Canine leishmaniasis surveillance in a northern Italy kennel

Global Distribution of Canine Visceral Leishmaniasis and the Role of the Dog in the Epidemiology of the Disease

Visceral leishmaniasis is a disease caused by protozoa of the species Leishmania (Leishmania) infantum (syn = Leishmania chagasi) and Leishmania (Leishmania) donovani, which are transmitted by hematophagous insects of the genera Lutzomyia and Phlebotomus. The domestic dog (Canis familiaris) is considered the main urban reservoir of the parasite due to the high parasite load on its skin, serving as a source of infection for sandfly vectors and, consequently, perpetuating the disease in the urban environment. Some factors are considered important in the perpetuation and spread of canine visceral leishmaniasis (CVL) in urban areas, such as stray dogs, with their errant behavior, and houses that have backyards with trees, shade, and organic materials, creating an attractive environment for sandfly vectors. CVL is found in approximately 50 countries, with the number of infected dogs reaching millions. However, due to the difficulty of controlling and diagnosing the disease, the number of infected animals could be even greater. In the four continents endemic for CVL, there are reports of disease expansion in endemic countries such as Brazil, Italy, Morocco, and Tunisia, as well as in areas where CVL is not endemic, for example, Uruguay. Socio-environmental factors, such as migration, drought, deforestation, and global warming, have been pointed out as reasons for the expansion into areas where it had been absent. Thus, the objective of this review is to address (i) the distribution of CVL in endemic areas, (ii) the role of the dog in the visceral leishmaniasis epidemiology and the factors that influence dog infection and the spread of the disease, and (iii) the challenges faced in the control of CVL.

The estimated distribution of autochthonous leishmaniasis by Leishmania infantum in Europe in 2005-2020

BACKGROUND

This study describes the spatial and temporal distribution between 2005 and 2020 of human and animal leishmaniasis by Leishmania infantum in European countries reporting autochthonous cases, and highlights potential activities to improve disease control.

METHODOLOGY/PRINCIPAL FINDINGS

It was based on a review of the scientific literature and data reported by the World Health Organization (WHO), the World Organization for Animal Health (WOAH) and the Ministries of Health, including hospital discharges in some countries. Autochthonous infections were reported in the scientific literature from 22 countries, including 13 and 21 countries reporting human and animal infections, respectively. In contrast, only 17 countries reported autochthonous human leishmaniasis cases to the WHO and 8 countries animal infections to the WOAH. The number of WOAH reported cases were 4,203, comprising 4,183 canine cases and 20 cases in wildlife. Of 8,367 WHO reported human cases, 69% were visceral leishmaniasis cases-of which 94% were autochthonous-and 31% cutaneous leishmaniasis cases-of which 53% were imported and mostly in France. The resulting cumulative incidence per 100,000 population of visceral leishmaniasis between 2005-2020, was highest in Albania (2.15 cases), followed by Montenegro, Malta, Greece, Spain and North Macedonia (0.53-0.42), Italy (0.16), Portugal (0.09) and lower in other endemic countries (0.07-0.002). However, according to hospital discharges, the estimated human leishmaniasis incidence was 0.70 in Italy and visceral leishmaniasis incidences were 0.67 in Spain and 0.41 in Portugal.

CONCLUSIONS/SIGNIFICANCE

Overall, there was no evidence of widespread increased incidence of autochthonous human leishmaniasis by L. infantum in European countries. Visceral leishmaniasis incidence followed a decreasing trend in Albania, Italy and Portugal, and peaked in Greece in 2013, 2014 and 2017, and in Spain in 2006-2007 and 2011-2013. Animal and human cutaneous leishmaniasis remain highly underreported. In humans, hospital discharge databases provide the most accurate information on visceral leishmaniasis and may be a valuable indirect source of information to identify hotspots of animal leishmaniasis. Integrated leishmaniasis surveillance and reporting following the One Health approach, needs to be enhanced in order to improve disease control.

Occurrence of Phlebotomine sand flies (Diptera: Psychodidae) in the northeastern plain of Italy

BACKGROUND

Recent climate and environmental changes have resulted in the geographical expansion of Mediterranean Leishmania infantum vectors towards northern latitudes and higher altitudes in different European countries, including Italy, where new foci of canine leishmaniasis have been observed in the northern part of the country. Northern Italy is also an endemic area for mosquito-borne diseases. During entomological surveillance for West Nile virus, mosquitoes and other hematophagous insects were collected, including Phlebotomine sand flies. In this study, we report the results of Phlebotomine sand fly identification during the entomological surveillance conducted from 2017 to 2019.

METHODS

The northeastern plain of Italy was divided by a grid with a length of 15 km, and a CO2-CDC trap was placed in each geographical unit. The traps were placed ~ 15 km apart. For each sampling site, geographical coordinates were recorded. The traps were operated every two weeks, from May to November. Sand flies collected by CO2-CDC traps were identified by morphological and molecular analysis.

RESULTS

From 2017 to 2019, a total of 303 sand flies belonging to the species Phlebotomus perniciosus (n = 273), Sergentomyia minuta (n = 5), P. mascittii (n = 2) and P. perfiliewi (n = 2) were collected, along with 21 unidentified specimens. The trend for P. perniciosus collected during the entomological surveillance showed two peaks, one in July and a smaller one in September. Sand flies were collected at different altitudes, from -2 m above sea level (a.s.l.) to 145 m a.s.l. No correlation was observed between altitude and sand fly abundance.

CONCLUSIONS

Four Phlebotomine sand fly species are reported for the first time from the northeastern plain of Italy. Except for S. minuta, the sand fly species are competent vectors of Leishmania parasites and other arboviruses in the Mediterranean Basin. These findings demonstrate the ability of sand flies to colonize new environments previously considered unsuitable for these insects. Even though the density of the Phlebotomine sand fly population in the plain areas is consistently lower than that observed in hilly and low mountainous areas, the presence of these vectors could herald the onset of epidemic outbreaks of leishmaniasis and other arthropod-borne diseases in areas previously considered non-endemic.

Canine Leishmaniasis: Serological Results in Private and Kennel Dogs Tested over a Six-Year Period (2009-2014) in Abruzzo and Molise Regions, Italy

This paper reports the results of serological tests for the detection of antibodies against Leishmania spp. in Abruzzo and Molise regions from 2009 to 2014, with the aim of evaluating the presence and distribution of canine leishmaniasis. Data were extracted from the Laboratory Information Management System (LIMS) of the Istituto Zooprofilattico Sperimentale of Abruzzo and Molise, and then the dog identification numbers were matched with those stored in the Canine Registries of the two regions to get information about the age of dogs at time of testing. Dogs were considered positive when having an IFAT (Indirect Fluorescent Antibody Test) titer ≥1:80. In total, 41,631 dogs were tested, 85.3% from Abruzzo and 14.7% from Molise. At the provincial level, the percentage of positive dogs ranged from 5.2% (L’Aquila, Abruzzo region) to 21.8% (Campobasso, Molise region). Findings are consistent with the hypothesis that in the coastal areas, the relationships between the host, the vector, and the agent are more favorable for the spreading of CanL, and it seems that densely populated urban internal areas have less favorable conditions. Being a dog hosted in a kennel seems not to be a factor increasing the probability that dogs show positivity, even in long-term sheltering conditions.

Serological, molecular and clinicopathological findings associated with Leishmania infantum infection in cats in Northern Italy

OBJECTIVES

The aims of this study were to investigate the prevalence of Leishmania species infection in cats in Northern Italy and to evaluate the associations between infection and signalment and clinicopathological data.

METHODS

The study was carried out in a veterinary university hospital from June to November 2017. Blood, urine, conjunctival swabs and hair were collected from all randomly selected cats. Leishmania species infection was evaluated using the indirect fluorescent antibody test (IFAT), setting a cut-off value of 1:80, and using real-time PCR on blood, conjunctival and hair samples. A complete blood count, serum chemistry profile, serum electrophoresis and urinalysis were also carried out. The cats were grouped on the basis of the results of the diagnostic criteria adopted in positive, negative and unconfirmed Leishmania cases. Non-parametric variables and continuous data were compared among the study groups using the χ2 test and the Mann-Whitney U-test, respectively.

RESULTS

One hundred and fifty-two cats were included. Nineteen of the 152 (12.5%) cats were positive (18/152 [11.8%] showed an IFAT titre of ⩾1:80 and 1/152 [0.7%] was real-time PCR-positive from a hair sample); 106/152 (69.7%) cats were negative; and 27/152 (17.8%) cats were unconfirmed for Leishmania species. Total proteins, beta2-globulin and gamma-globulin were significantly increased in the positive Leishmania group compared with the negative group.

CONCLUSIONS AND RELEVANCE

The results of the present study demonstrated the spread of Leishmania infantum infection in cats in Northern Italy. Hyperproteinaemia and hypergammaglobulinaemia appeared to be significant clinicopathological abnormalities in this population of cats with L infantum infection.

Prognostic Factors and Life Expectancy in Canine Leishmaniosis

Canine leishmaniosis (CanL) is a chronic and potentially fatal disease. The prognosis of CanL depends on the severity of the clinical signs and clinicopathological abnormalities presented by the dog at the time of diagnosis. This study aims to estimate the survival time of dogs with CanL, determining the prognostic value of different clinical and clinicopathological parameters. Medical records of 99 dogs diagnosed with CanL in five veterinary centers of the Alentejo region (Portugal) were examined retrospectively. The majority of dogs presented hyperproteinemia, moderate normocytic normochromic anemia, normal blood urea and creatinine levels and were classified as stage 1 according to the International Interest Society (IRIS) guidelines at the time of diagnosis. The severity of anemia, presence of concomitant infectious diseases at the time of diagnosis and the anti-Leishmania therapy were correlated with the survival time. The influence of renal dysfunction was evaluated by Receiver Operating Characteristic (ROC) curve and survival analysis. Survival analysis demonstrated that patients classified as IRIS 1 at the time of diagnosis survived more than four years, in contrast with dogs classified as IRIS 2 that survived around two and half years and dogs classified as IRIS 3-4 that survived around one month. IRIS stage deteriorated during the course of CanL in one third of the dogs and was the principal cause of death or euthanasia in a high proportion of animals. In some cases, dogs did not receive anti-Leishmania treatment or abandoned the veterinary follow-ups, which may have considerable repercussions for animal wellbeing and public health. This study reinforces the value of blood urea and creatinine levels as prognostic factors in CanL.

Leishmania infantum and Dirofilaria immitis infections in Italy, 2009-2019: changing distribution patterns

BACKGROUND

For long time, canine leishmaniosis (CanL) was considered endemic in the southern, central, and insular regions of Italy, whereas heartworm disease (HW) caused by Dirofilaria immitis was considered endemic in the northern region and in the swampy Po Valley. Following the reports of new foci of both diseases, in this study we update the distribution patterns and occurrence of new foci of CanL and HW discussing the main drivers for the changes in the epidemiology of these two important zoonotic canine vector-borne diseases.

METHODS

Based on the statistical analyses of serological assays (n = 90,633) on L. infantum exposure and D. immitis infection performed by two reference diagnostic centres in Italy over a ten-year period (2009-2019) irrespective of the anamnesis of dogs. The distribution patterns of both parasites are herein presented along with the occurrence of new foci.

RESULTS

Results highlighted the changing distribution patterns of L. infantum vs D. immitis infection in Italy. CanL is endemic in some areas of northern regions and HW has endemic foci in central and southern regions and islands. Significant differences in L. infantum exposure and HW infection prevalence among the study macroareas were detected. The overall results of the positive tested samples were 28.2% in southern Italy and islands, 29.6% in central Italy and 21.6% in northern Italy for L. infantum and 2.83% in northern Italy, 7.75% in central Italy and 4.97% in southern Italy and islands for HW. HW positivity significantly varied over years (χ2 = 108.401, df = 10, P < 0.0001), gradually increasing from 0.77% in 2009 to 8.47% in 2016-2017.

CONCLUSIONS

New potential epidemiological scenarios are discussed according to a range of factors (e.g. environmental modifications, occurrence of competent insect vectors, transportation of infected animals to non-endemic areas, chemoprophylaxis or vector preventative measures), which may affect the current distribution. Overall, the results advocate for epidemiological surveillance programmes, more focussed preventative and control measures even in areas where few or no cases of both diseases have been diagnosed.

Seroprevalence, Clinical, and Pathological Characteristics of Canine Leishmaniasis in a Central Region of Colombia

Introduction

Leishmaniasis is a zoonotic disease which is caused by protozoan parasites of the genus Leishmania. Canids are the most important reservoir of the parasites; however, limited data are available on the species of Leishmania prevalent in these animals and their impact on human health. The objective of this study was to estimate the seroprevalence of leishmaniasis in dogs from an inter-Andean region of Colombia during July 2016–July 2017, and to describe the clinical and histopathological features of the disease.

Material and Methods

A total of 155 dogs were subjected to clinical examination and a serological test for detection of antibodies against Leishmania. Necropsy was carried out on positive animals and tissue samples were processed by routine histopathology.

Results

Altogether 19 dogs were positive in the serological test, establishing a 12% seroprevalence of Leishmania. Clinical examination and necropsy revealed exfoliative and ulcerative dermatitis with haemorrhagic borders on the ears, head, nose, and legs. Histopathology revealed severe multifocal dermatitis with abundant Leishmania amastigotes within the cytoplasm of phagocytic cells, depletion of lymphocytes in lymphoid tissues, interstitial pneumonia, and interstitial nephritis. Tissue samples were positive for Leishmania by PCR.

Conclusion

The macro- and microscopic changes correlated with the presence of Leishmania as established by serological test and PCR.

A historical review on vector distribution and epidemiology of human and animal leishmanioses in Eastern Europe

Many canine diseases, infectious or parasitic, have been newly reported as autochthonous in the last few years in Eastern Europe. This is notably evident for vector-borne diseases. The mechanisms behind the particular epidemiological pattern of infectious and parasitic diseases of pets in Eastern Europe are complex. Most countries from Eastern Europe are regarded as non-endemic for leishmaniosis, with sporadic cases only in both humans and dogs. However, recently, new imported or autochthonous cases are reported every year. The aim of the current review is to synoptically review and critically analyse the epidemiological situation of leishmaniosis and the distribution of the sand fly vectors in Eastern Europe, namely in Romania, Hungary, Czech Republic, Slovakia, Bulgaria, Poland, Moldova, Ukraine, and Belarus.

Leishmania infantum, Dirofilaria spp. and other endoparasite infections in kennel dogs in central Italy

Prevalence and risk factors of Leishmania infantum, Dirofilaria spp. and other potentially zoonotic or canine-specific endoparasite infections were assessed in 639 kennel dogs from central Italy. To this end, individual blood and fecal samples were examined using parasitological, immunological and molecular techniques. The presence of compatible clinical pictures, as well as age and gender were considered as putative risks factors. To evaluate risk factors, multivariable analysis with logistic regression and univariable analysis with a Chi square test and a Fischer's exact test were performed. Overall, 52.6% of dogs (95% CI 48.6-56.5) were found positive, while 39.6% of dogs (95% CI 35.8-43.5) were infected by potentially zoonotic species. Leishmania infantum and Dirofilaria repens showed prevalences of 2.5% (95% CI 1.5-4.1) and 2.8% (95% CI 1.7-4.5), respectively. The prevalence of cardiorespiratory parasites was 7.8% (95% CI 5.9-10.3) and included the species Angiostrongylus vasorum, Eucoleus aerophilus, Eucoleus boehmi and D. immitis; the latter showed a prevalence of 0.2% (95% CI 0.001-1). Intestinal parasites were significantly prevalent (38.8%, 95% CI 35-42.7) and they consisted mainly of species of major zoonotic concern, including ancylostomatids, Toxocara canis, Giardia duodenalis, Dipylidium caninum, Taeniidae, Strongyloides stercoralis and Cryptosporidium parvum. Endoparasites were significantly prevalent in clinically suspected dogs. Leishmania infantum and cardiorespiratory nematodes were prevalent in older dogs, while intestinal parasites were prevalent in younger dogs. Results show high dog and public health risks in kennels in central Italy, and suggest the need for more effective control measures.

The quest for canine leishmaniasis in Romania: the presence of an autochthonous focus with subclinical infections in an area where disease occurred

BACKGROUND

Canine leishmaniasis is a severe, potentially life-threatening, systemic vector-borne disease of dogs caused by protozoan parasites of the genus Leishmania. Romania has been traditionally regarded as a non-endemic country for leishmaniasis with sporadic human disease cases. However, the recent report of an autochthonous canine leishmaniasis case (the first in the last 80 years) suggested the presence of an infection focus in the area of Râmnicu Vâlcea. The present study describes a survey of canine leishmaniasis in this geographical area with comparison to a georeferenced dataset of sand fly distribution based on historical literature records.

METHODS

The study was carried out in Râmnicu Vâlcea and included samples (serum, blood and conjunctival swabs) collected from 80 dogs including client-owned dogs from two local practices and dogs from two public shelters. Serum anti-leishmanial antibodies were assessed by ELISA. All blood and conjunctival samples were assessed by real-time quantitative PCR, targeting the leishmanial kinetoplast minicircle DNA.

RESULTS

Three dogs (3.7 %) were seropositive and another four (5.0 %) showed borderline results indicative of exposure or infection. TaqMan PCR was performed for all dogs, on both blood and conjunctival swabs. Seven dogs (8.7 %) were positive by conjunctival swab PCR and one dog (1.2 %) by blood PCR. None of the positive dogs presented clinical signs compatible with canine leishmaniasis.

CONCLUSIONS

This is the first study evaluating canine leishmaniasis in a dog population in Romania by both highly sensitive PCR and serology. Although the prevalence was relatively low compared to other endemic regions, our results clearly demonstrate the presence of a canine leishmaniasis focus in Romania.

Dirofilaria immitis and Angiostrongylus vasorum: the contemporaneous detection in kennels

BACKGROUND

The cardiopulmonary nematodes Dirofilaria immitis and Angiostrongylus vasorum are increasingly reported in dogs and are responsible for two diseases with overlapping endemic areas, especially in Europe: dirofilariosis and angiostrongylosis. The reasons for their apparent emergence are unknown, but several factors (e.g. increased disease awareness, better diagnostic tools, climatic changes, seasonal population dynamics and movements of animals) may play a role in the recent rise in reports of infection in the various countries of Europe. The aim of this study was to investigate the seroprevalence of D. immitis (by DiroCHECK® ELISA) and the fecal presence of first stage larvae (L1) of A. vasorum (by FLOTAC) in dogs from 68 kennels of the Campania region (southern Italy). The fecal samples were collected from pooled samples using the box as epidemiological unit. To the authors's knowledge, this is the first cross-sectional survey conducted at regional-scale in Italy and in Europe on the contemporaneous detection of D. immitis antigens and A. vasorum L1 in kennels.

RESULTS

Antigens of D. immitis were detected in 24/537 (4.4%; 95% Confidence Interval = 3.0-6.7) dogs in 6 out of the 68 kennels (8.8%; 95% CI = 3.6-18.9). The 24 positive samples for D. immitis antigen were tested also with AngioDetect® and only 1 sample was seropositive for A. vasorum with a prevalence of 4.2%. A. vasorum L1 were detected in dogs from 9 out of the 68 kennels (13.2%; 95% CI = 21.8-44.9). Pooled fecal samples from 25 boxes out of the 1360 analyzed resulted positive to A. vasorum L1 (1.8%; 95% CI = 1.2-2.7).

CONCLUSIONS

The present study indicates that cardiopulmonary nematodes are present in Campania region in symptomatic dogs as well as in asymptomatic ones. Therefore, regular parasitological surveillance, appropriate treatment strategies and high quality standard of hygiene are required to guarantee the health and welfare of kennel dogs.

Helminth control in kennels: is the combination of milbemycin oxime and praziquantel a right choice?

Background

Kennel dogs are at the high risk of infections with intestinal and extra-intestinal helminths. Therefore, regular parasitological surveillance, appropriate treatment strategies and high quality standard of hygiene are required to guarantee the health and welfare of kennel dogs. The aim of the present study was to evaluate the efficacy of helminth control in kennels using different broad-spectrum anthelmintics that are routinely used in canine veterinary practice. Particular attention was given to the field efficacy and ease-of-use of each product.

Methods

The study was conducted in 3 public kennels in the Campania region (southern Italy). Eighteen boxes from each of the three kennels were selected for treatment based on faecal egg counts (FECs) at Day −30. The treatments were conducted using tablets containing combinations of: i) milbemycin oxime and praziquantel (Milbemax®); ii) pyrantel embonate, febantel and praziquantel (Drontal Plus Flavour®), and; iii) pyrantel pamoate, oxantel pamoate and praziquantel (Nemex® POP). All dogs were treated on Day 0 and sampled on Days 0, 7, 14 and 21 for copromicroscopic analyses. The FLOTAC dual technique on pooled samples was used with efficacy determined by reduction in FECs.

Results

At Day −30 intestinal nematodes (hookworms, Toxocara, Trichuris) and cestodes (Dypilidium caninum) were found. Milbemax® showed 100% efficacy against all the helminths in all the kennels. Drontal Plus Flavour® was 100% effective against hookworms in all the kennels but gave lower efficacy against T. canis (range = 97.1-100%) and T. vulpis (range = 95.6-100%). Nemex® POP was also 100% effective against hookworms in all kennels but less effective against T. canis (range = 95.7-100%) and T. vulpis (range = 95.7-100%). All three drugs were 100% effective against D.caninum.

Conclusions

Milbemax®was fully effective against all the helminthes and was palatable and ease-of-use for all the dogs. It is the optimum choice for the treatment and prevention of helminth infections in kennel dogs under field conditions.

The first report of autochthonous non-vector-borne transmission of canine leishmaniosis in the Nordic countries

Background

Leishmania spp. are zoonotic protozoans that infect humans and other mammals such as dogs. The most significant causative species in dogs is L. infantum. In dogs, leishmaniosis is a potentially progressive, chronic disease with varying clinical outcomes. Autochthonous cases of canine leishmaniosis have not previously been reported in the Nordic countries.

Results

In this report we describe the first diagnosed autochthonous cases of canine leishmaniosis in Finland, in which transmission via a suitable arthropod vector was absent. Two Finnish boxers that had never been in endemic areas of Leishmania spp., had never received blood transfusions, nor were infested by ectoparasites were diagnosed with leishmaniosis. Another dog was found with elevated Leishmania antibodies. A fourth boxer dog that had been in Spain was considered to be the source of these infections. Transmission occurred through biting wounds and semen, however, transplacental infection in one of the dogs could not be ruled out.

Two of the infected dogs developed a serious disease and were euthanized and sent for necropsy. The first one suffered from membranoproliferative glomerulonephritis and the second one had a chronic systemic disease. Leishmania sp. was detected from tissues by PCR and/or IHC in both dogs. The third infected dog was serologically positive for Leishmania sp. but remained free of clinical signs.

Conclusions

This case report shows that imported Leishmania-infected dogs may pose a risk for domestic dogs, even without suitable local arthropod vectors.

A case of imported Leishmania infantum cutaneous leishmaniasis; an unusual presentation occurring 19 years after travel

Background

Leishmania infantum is a flagellated protozoan parasite that is able to parasitize blood and tissue. Leishmania species cause a spectrum of clinical disease with cutaneous, visceral or mucosal involvement. L. infantum is recognised as a cause of visceral leishmaniasis (VL) and is less commonly reported as a cause of cutaneous leishmaniasis (CL) from countries around the Mediterranean basin. This is the first report of imported L. infantum CL to Australia and is remarkable for a 19 year period between the patient's exposure to an endemic region, and the manifestation of symptoms.

Case presentation

A 76 year old Italian-born man presented to our institution with a non-healing lesion over his upper lip, abutting his nasal mucosa. The patient had travelled to Italy, an endemic area for L. infantum 19 years earlier but had resided in Australia, a non-endemic area since. Histopathology performed on a biopsy of the lesion demonstrated findings consistent with CL. A species specific polymerase chain reaction (PCR) performed on the tissue detected L. infantum. The patient had complete clinical recovery following treatment with Liposomal amphotericin B at a dose of 3 mg/kg for five days followed by a subsequent 3 mg/kg dose at day ten.

Conclusions

L. infantum should be recognised as a cause of imported CL in returned travellers from the Mediterranean. In this case, the incubation period for L. infantum CL was at least 19 years. This case adds to the described spectrum of clinical presentations of leishmaniasis and supports the theory of parasite persistence underlying natural immunity and recurrence of disease. Clinicians should consider L. infantum CL in the differential diagnosis of a non-healing skin lesion in any patient who reports travel to the Mediterranean, even when travel occurred several years before clinical presentation.

Electronic supplementary material

The online version of this article (doi:10.1186/s12879-014-0597-x) contains supplementary material, which is available to authorized users.

Modelling canine leishmaniasis spread to non-endemic areas of Europe

Expansion of sandflies and increasing pet travel have raised concerns about canine leishmaniasis (CanL) spread to new areas of Europe. This study aimed to estimate the probability of CanL introduction and persistence following movements of infected dogs. Stochastic modelling was used to estimate the probabilities of (1) CanL infection during travels or imports of infected dogs (P inf and P infCA, respectively), (2) CanL persistence in a dog network with sandflies after introduction of an infected dog (P per), and (3) persistence in a CanL-free region (P per region) for N dogs moving between endemic and free regions. Different mitigation measures (MMs) were assessed. P inf [7.8%, 95% predictive interval (PI) 2.6-16.4] and P per (72.0%, 95% PI 67.8-76.0) were reduced by use of repellent, vaccine, prophylactic medication, and insecticide, in decreasing order of effectiveness. Testing and exclusion of positive dogs was most effective in reducing P per region for a small N. The spread of CanL to CanL-free areas with sandflies is thus likely, but can be reduced by MMs.

Evidence of Leishmania (Leishmania) infantum infection in dogs from Juiz de Fora, Minas Gerais State, Brazil, based on immunochromatographic dual-path platform (DPP®) and PCR assays

In Brazil, domestic dogs are branded as the primary reservoir for zoonotic visceral leishmaniasis, due to the clear positive correlation observed between human and canine infection rates. This study aimed to carry out a serological survey of canine visceral leishmaniasis (CVL) in dogs housed at a public kennel in the municipality of Juiz de Fora, Minas Gerais State, Brazil, using the immunochromatographic TR DPP^® CVL rapid test. Additionally, conventional and/or real time PCR assay was used to detect and confirm L. infantum infection in the DPP positive dogs only. Of the 400 dogs studied, most did not present clinical signs for CVL (p < 0.05), and fifteen (3.8%) were seropositive in the DPP test. There was no statistically significant difference between the DPP seropositive dogs and the clinical signs of the disease (p > 0.05). Both conventional and real time PCR tests confirmed L. infantum infection in nine (75.0%) of the twelve DPP seropositive dogs that remained alive during the follow-up period. This study is the first seroepidemiologic survey of CVL held in the city of Juiz de Fora, and the results reinforce the idea that this disease is currently in a process of expansion and urbanization in Brazil. Furthermore, this study highlights the use of the DPP test as an alternative for diagnosing CVL in large and mid-sized cities, due to its ease of implementation.

Immunotherapy and Immunochemotherapy in Visceral Leishmaniasis: Promising Treatments for this Neglected Disease

Leishmaniasis has several clinical forms: self-healing or chronic cutaneous leishmaniasis or post-kala-azar dermal leishmaniasis; mucosal leishmaniasis; visceral leishmaniasis (VL), which is fatal if left untreated. The epidemiology and clinical features of VL vary greatly due to the interaction of multiple factors including parasite strains, vectors, host genetics, and the environment. Human immunodeficiency virus infection augments the severity of VL increasing the risk of developing active disease by 100–2320 times. An effective vaccine for humans is not yet available. Resistance to chemotherapy is a growing problem in many regions, and the costs associated with drug identification and development, make commercial production for leishmaniasis, unattractive. The toxicity of currently drugs, their long treatment course, and limited efficacy are significant concerns. For cutaneous disease, many studies have shown promising results with immunotherapy/immunochemotherapy, aimed to modulate and activate the immune response to obtain a therapeutic cure. Nowadays, the focus of many groups centers on treating canine VL by using vaccines and immunomodulators with or without chemotherapy. In human disease, the use of cytokines like interferon-γ associated with pentavalent antimonials demonstrated promising results in patients that did not respond to conventional treatment. In mice, immunomodulation based on monoclonal antibodies to remove endogenous immunosuppressive cytokines (interleukin-10) or block their receptors, antigen-pulsed syngeneic dendritic cells, or biological products like Pam3Cys (TLR ligand) has already been shown as a prospective treatment of the disease. This review addresses VL treatment, particularly immunotherapy and/or immunochemotherapy as an alternative to conventional drug treatment in experimental models, canine VL, and human disease.

A summary of the evidence for the change in European distribution of phlebotomine sand flies (Diptera: Psychodidae) of public health importance

The phlebotomine sand flies (Diptera: Psychodidae, Phlebotominae) are vectors of several infectious pathogens. The presence of a sand fly vector is considered to be a risk factor for the emergence of leishmaniasis in temperate Europe. Hence, the occurrence of phlebotomine sand flies and any changes in their distribution is important in determining the potential change in distribution of leishmaniasis in Europe. Therefore, published evidence for a changing distribution of the important phlebotomine sand fly vectors of leishmaniasis and phlebovirus infection in Europe is reviewed. This paper presents evidence of an increasing risk of establishment by sand fly species, especially for the Atlantic Coast and inland parts of Germany, Switzerland, and Austria. In addition to detection in potentially appropriate areas, the findings show areas of potential future establishment of the species. The most important and urgent necessity within the community of entomologists working on phlebotomines is the need to record the extremes of distribution of each species and obtain data on their regional presence/absence along with increased sharing of the data throughout European projects.

Effect of night time-intervals, height of traps and lunar phases on sand fly collection in a highly endemic area for canine leishmaniasis

The activity of phlebotomine sand flies was monitored in a sub-urban area of Sicily in order to acquire data on seasonality and to elucidate the effect of the night time-intervals, height of traps from ground and lunar phases on the abundance of the capture. The study was conducted in the farm of the University of Messina (Italy). Light traps were placed as in the following: biweekly, from dusk to dawn, and from May to November; for three consecutive nights from 18:00 to 6:00, with the net bag being changed every 2h; for 30 days, at different heights from 18:00 to 6:00. A total of five species (i.e., Phlebotomus perniciosus, Phlebotomus neglectus, Phlebotomus sergenti, Phlebotomus perfiliewi, and Sergentomyia minuta), three of which are proven vectors of Leishmania infantum, were captured. The most abundant species was P. perniciosus (73.3%) followed by S. minuta (23.3%). The highest number of phlebotomine sand flies was collected in August and September with a peak of collection recorded in the evening (i.e., from 20:01 to 22.00). The number of phlebotomine sand flies collected at 50cm above the ground was significantly higher (P=0.041) than that captured at 150cm. Results of this study shed light on the ecology of main phlebotomine species in the Mediterranean area, and on the influence of some factors, such as time and height of traps, on the light trap capture efficiency.

The frequency and distribution of canine leishmaniosis diagnosed by veterinary practitioners in Europe

This study aimed to evaluate the frequency and spatial distribution of canine leishmaniosis (CanL) in France, Greece, Italy, Portugal and Spain. An online questionnaire investigated the location and frequency of CanL cases diagnosed by veterinary practitioners. Further data from the practice management systems of veterinary clinics in France were provided by a financial benchmarking company in relation to all treatment and test invoice data from participating practices. The geographical and temporal web interest in leishmaniosis was explored using Google Trends. Veterinary practitioners from France, Greece, Italy, Portugal and Spain completed 1231 questionnaires. The percentage of practice-attending dogs with a veterinary diagnosis of CanL ranged from 0.71% in France to 7.80% in Greece. However, due to regional differences in response rates, particularly in France, the mean regional estimates may better reflect the disease burden. Benchmarking data relating to approximately 180,000 dogs estimated that 0.05% of dogs attending veterinary clinics were treated for CanL or euthanased with suspected CanL in France. The regional frequency of Google web queries for leishmaniosis generally reflected the spatial patterns of disease identified from the other data sources. In conclusion, CanL was a relatively common diagnosis in veterinary clinics in many regions of the countries studied. Knowledge of CanL in endemic areas can direct the use of preventative measures and help estimate the likelihood of infection in dogs visiting or inhabiting these countries.

A surveillance program on canine leishmaniasis in the public kennels of Emilia-Romagna Region, Northern Italy

Since 2007, a canine leishmaniasis (CanL) surveillance program has been carried out in public kennels of the Emilia-Romagna region with the aim of providing health guarantees for dog adoptions. According to this program, monitoring activities were performed to verify the presence of sandflies and infected dogs, and a specific CanL risk class was assigned to each kennel, resulting in different control approaches (entomological and/or serological monitoring, clinical surveillance, therapeutic treatment of infected dogs, protections against vector bites). From 2007 to 2012, 20,931 dogs, 89.8% of which were identified by microchip and housed in 73 kennels, were examined using an indirect fluorescent antibody test. In all, 528 (2.8%) dogs tested positive, and 43.0% of these were asymptomatic. The authors used monitoring results, in particular serological tests performed on dogs at admittance to the kennel and annual controls of sentinel dogs, to estimate CanL risk in the whole region and to evaluate the efficacy of the preventive measures adopted. CanL seroprevalence in dogs tested at the admittance in kennels increased significantly from 2010 (1.0%; 29/2858) to 2012 (2.4%; 69/2841). In contrast, the number of seroconversions in sentinel dogs was stable in 2010 (1.2%; 11/896) and 2011 (1.6%; 13/825) and decreased in 2012 (0.9%; 8/850), suggesting the efficacy of the preventive measures applied.

Subtractive phage display selection from canine visceral leishmaniasis identifies novel epitopes that mimic Leishmania infantum antigens with potential serodiagnosis applications

Visceral leishmaniasis (VL) is a zoonotic disease that is endemic to Brazil, where dogs are the main domestic parasite reservoirs, and the percentages of infected dogs living in regions where canine VL (CVL) is endemic have ranged from 10% to 62%. Despite technological advances, some problems have been reported with CVL serodiagnosis. The present study describes a sequential subtractive selection through phage display technology from polyclonal antibodies of negative and positive sera that resulted in the identification of potential bacteriophage-fused peptides that were highly sensitive and specific to antibodies of CVL. A negative selection was performed in which phage clones were adhered to purified IgGs from healthy and Trypanosoma cruzi-infected dogs to eliminate cross-reactive phages. The remaining supernatant nonadhered phages were submitted to positive selection against IgG from the blood serum of dogs that were infected with Leishmania infantum. Phage clones that adhered to purified IgGs from the CVL-infected serum samples were selected. Eighteen clones were identified and their reactivities tested by a phage enzyme-linked immunosorbent assay (phage-ELISA) against the serum samples from infected dogs (n = 31) compared to those from vaccinated dogs (n = 21), experimentally infected dogs with cross-reactive parasites (n = 23), and healthy controls (n = 17). Eight clones presented sensitivity, specificity, and positive and negative predictive values of 100%, and they showed no cross-reactivity with T. cruzi- or Ehrlichia canis-infected dogs or with dogs vaccinated with two different commercial CVL vaccines in Brazil. Our study identified eight mimotopes of L. infantum antigens with 100% accuracy for CVL serodiagnosis. The use of these mimotopes by phage-ELISA proved to be an excellent assay that was reproducible, simple, fast, and inexpensive, and it can be applied in CVL-monitoring programs.

First survey on canine leishmaniasis in a non classical area of the disease in Spain (Lleida, Catalonia) based on a veterinary questionnaire and a cross-sectional study

The Spanish distribution of canine leishmaniasis (CanL) is heterogeneous and very few data are available for the north of the country, including the province of Lleida (Catalonia, Spain). This work describes the results obtained from a questionnaire sent to veterinarians throughout the province of Lleida. The majority of veterinarians (25/32, 78.1%) believed CanL cases were increasing and that the dogs had been infected locally (30/32, 93.8%). Also, a cross-sectional study was performed on the seroprevalence of CanL in kennel dogs, with and without compatible clinical signs, in the county of Pallars Sobirà (Pyrenees of Lleida), where an autochthonous case of CanL had been previously detected. Four serological tests were used (IFAT, ELISA, Western blot, ICF) and dogs that tested positive with at least two immunological methods were considered seropositive and probably infected. 33.1% (48/145) of the dogs were seropositive. The results of a mixed logistic regression model showed that the risk of seropositivity increased with age (OR=1.35, p-value=0.002), among dogs living in the southern part of Pallars Sobirà (OR=6.20, p-value=0.025) and among dogs whose owners considered their animals to be at risk of leishmaniasis infection (OR=1.26, p-value=0.024) and who were unaware of anti-sand fly preventive methods (OR=11.6, p-value=0.009). The risk decreased when dogs lived in an urban-periurban habitat (OR=0.17, p-value=0.002). The information gathered in the veterinary questionnaires helped us to define the knowledge, perception and awareness of the disease in a naïve region, supporting the hypothesis of an existing CanL focus in Pallars Sobirà, which was confirmed by the seroepidemiological survey. The seroprevalence study carried out on kennel dogs of local origin proved useful for detecting an autochthonous focus of leishmaniasis through the analysis of a small number of animals.

Canine leishmaniosis in the Old and New Worlds: unveiled similarities and differences

Canine leishmaniosis is a potentially life-threatening disease which is spreading geographically in the Old and New Worlds, where different diagnostic procedures, treatments, and control strategies are currently in place. This Opinion article outlines the similarities and differences between canine leishmaniosis in the Old and New Worlds, with emphasis on South America and Europe. Finally, it calls the attention of veterinary and public health authorities to standardize and improve practices for diagnosing, treating, and preventing the disease.

Current situation of Leishmania infantum infection in shelter dogs in northern Spain

Background

Canine leishmaniosis (CanL) caused by Leishmania infantum is a widespread endemic disease in the Mediterranean basin, though, so far, the north of Spain has been considered a non-endemic area. The aim of the present study was to determine the prevalence of specific antibodies to L. infantum among stray dogs living in shelters in this area, and to evaluate the clinical status (both clinical signs and clinico-pathological abnormalities) of seropositive dogs. Besides L. infantum infection, the epidemiological role of variables like sex, breed and age was also assessed.

Methods

Over the year 2011 a cross-sectional study was conducted on a total of 418 stray dogs. A preliminary entomological survey was carried out using CDC-light traps. The chi-squared test was used to examine relationships between L. infantum seroprevalence and the remaining variables.

Results

The overall seroprevalence of L. infantum infection detected was 3% in the Cantabrian coast. In Orense the seroprevalence was 35.6%. In this latter region, the presence of sand fly, Phlebotomus perniciosus was also detected.

In general, seropositivity for L. infantum was related to size (large breed dogs versus small) and age, with a significantly higher seroprevalence recorded in younger (0-3 years) and older dogs (> 7 years) than adult dogs. Clinical signs of CanL were observed in 41.3% of the seropositive dogs. The seropositivity for L. infantum infection associated with the presence of clinical signs and/or abnormal laboratory findings shows a prevalence of 4.5%.

Conclusion

Our data provide new insight into the prevalence of CanL across northern Spain. The situation observed in Orense seems to be worsening compared to the few reports available, with figures being similar to those cited for known endemic areas of Spain. Besides, the presence of P. perniciosus in Orense points out to a risk of the spread of this zoonotic disease in this geographical area. These findings identify a need for an active search for the sand fly vectors of L. infantum across the entire northern spanish region including the rest of Galicia, Asturias, Cantabria and the Basque Country.