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1.
Human visceral leishmaniasis is an emergent/re-emergent parasitic zoonotic disease in Europe caused by Leishmania infantum, with domestic dog as its main reservoir host. This study presents the results of a canine epidemiological survey in a mediterranean region where human and canine leishmaniasis (CanL) are endemic - Portugal. The main goal was to identify risk factors, which can be relevant for Leishmania infection control. The national survey was carried out in January 2009 with a screening of 3974 dogs from all 18 districts of mainland Portugal. Direct Agglutination Test was used for the detection of anti-Leishmania antibodies in canine blood. An overall CanL true prevalence of 6.31% was observed. Apparent prevalence at district level ranged from 0.88% to 16.16%, with the highest prevalence in the interior regions. Identified risk factors for positivity were: dogs of 2 years and older (adjusted odds ratio OR=5.39); spending exclusively/most of the time outdoors (OR=2.51); origin from the interior of Portugal in comparison to littoral/coast districts (OR=2.51); not having long fur (OR=2.03); and being pure exotic (OR=1.67). The results confirm the leishmaniasis endemicity in Portugal and the dynamic character of prevalence as new foci emerged and old foci lost their importance. The dog's age, fur size, district and living outdoors as opposed to indoors were more important than dog breeds and insecticide treatment in the transmission of Leishmania infection. The future of CanL prevention and control rely on an integrated approach involving veterinarians, dog owners and health authorities in order to reduce the canine infection risk and consequently, the human zoonotic visceral leishmaniasis.  相似文献   

2.
Canine leishmaniasis (CanL), caused by Leishmania infantum, is widely distributed in many Mediterranean countries and is considered endemic in southern and central Italy with prevalence reaching up to 48.4%. Determination of the incidence would be useful as a measure of the risk of infection, then to evaluate the usefulness of control measures and to estimate whether a new focus is autochthonous or imported. This study was performed on two sites in the Apulia region of southern Italy, namely sites A and B. A total of 262 dogs were included in the evaluation of incidence, 94 farm dogs from site A and 168 dogs (92 farm and 76 kennel dogs) from site B. The incidence of infection was determined by using two different approaches: in site A by means of incidence density rate (IDR); in site B by the yearly seroconversion rate. In site A, the IDR was calculated at 4.25% dog-years; in site B the yearly incidence rate was of 9.52% (6.5% and 13.1% in farm and kennel dogs, respectively). The strength and weakness of the two different approaches (i.e. annual monitoring or monthly interval monitoring) for calculating the incidence of CanL in an endemic area have been discussed.  相似文献   

3.
The spread of human leishmaniasis has prompted the scientific community to study dogs as reservoirs for Leishmania infantum. Canine leishmaniasis (CanL) is widespread in the Mediterranean area with a prevalence of up to 50%. The first step toward controlling the disease is to monitor its distribution, mainly in stray dogs. The validity of a recombinant K39 (rK39) dipstick test, commercially available for the serodiagnosis of human leishmaniasis, was evaluated using sera from 165 dogs selected on the basis of positive or negative lymph node smears at parasitological examination. The results were compared with the indirect fluorescent antibody test (IFAT) (cutoff 1:80). Sera from a group of dogs with other diagnosed diseases but negative for leishmaniasis were also tested to evaluate any cross-reactivity. Various procedures were used for testing whole blood samples. The relative specificity of the rK39 dipstick and IFAT was 100% (97 of 97) and 98.97% (96 of 97), whereas the relative sensitivity was 97.06% (66 of 68) and 98.53% (67 of 68), respectively. The results of the dipstick and IFAT corresponded except for 2 sera (k = 0.987). This data confirm the usefulness of rK39 antigen for diagnosing CanL both in symptomatic and asymptomatic dogs. The rK39 dipstick proved to be a rapid, sensitive, and specific test that may be very useful in the field for large-scale screening and also in veterinary practice, requiring minimal equipment and operator expertise.  相似文献   

4.
The efficacy of imidacloprid 10%and permethrin 50% (Advantix; Bayer AG, Germany) in a spot-on formulation was evaluated in the field as a control measure to prevent canine leishmaniasis (CanL) in dogs in an endemic area of southern Italy. In February 2005, out of 845 dogs initially tested for CanL, 631 dogs which tested negative (315 from a kennel in Bari (KB) and 316 from a kennel in Ginosa (KG)) in a serological and a parasitological examination were allocated to one of three groups: Group A-treated with imidacloprid 10% and permethrin 50% once a month; Group B-treated every 2 weeks; and Group C-untreated control animals. All the dogs were examined serologically and parasitologically for CanL prior to the start of the study, in November 2005 (end of the sandfly season) and in March 2006 (end of the study). An initial CanL seroprevalence of 24.7% (209 dogs) was detected in KB and KG. In KB Leishmania infection, inferred by positivity in at least one of the three tests performed at the interim or final follow-up, was found in one animal from Group A and in nine from Group C. No positive animals were detected in Group B, thus giving a final protection efficacy of 88.9% in Group A and 100% in Group B. In KG Leishmania infection was identified in one animal from Groups A and B, respectively, and 11 from Group C (protection efficacy of 90.36% in Group A and 90.73% in Group B). The incidence density rates (IDRs) of infection in both Groups A and B at each kennel were statistically significantly lower than that registered in Group C (KB p<0.05 and KG p<0.01). The results clearly show that a combination of imidacloprid 10% and permethrin 50%, by virtue of its repellent activity against sandflies, is effective under both application regimes in preventing CanL in the field in endemic areas.  相似文献   

5.
Aiming to improve the diagnosis of canine leishmaniasis (CanL) in an endemic area of the Northwest region of S?o Paulo State, Brazil, the efficacy of parasitological, immunological and molecular diagnostic methods were studied. Dogs with and without clinical signs of the disease and positive for Leishmania, by direct parasite identification on lymph node smears and/or specific antibody detection by ELISA, were selected for the study. According to the clinical signs, 89 dogs attending the Veterinary Hospital of UNESP in Ara?atuba (SP, Brazil) were divided into three groups: symptomatic (36%), oligosymptomatic (22%) and asymptomatic (22%). Twenty-six dogs from an area non-endemic for CanL were used as negative controls (20%). Fine-needle aspiration biopsies (FNA) of popliteal lymph nodes were collected and Diff-Quick-stained for optical microscopy. Direct immunofluorescence, immunocytochemistry and parasite DNA amplification by PCR were also performed. After euthanasia, fragments of popliteal lymph nodes, spleen, bone marrow and liver were collected and processed for HE and immunohistochemistry. Parasite detection by both HE and immunohistochemistry was specifically more effective in lymph nodes, when compared with the other organs. Immunolabeling provided higher sensitivity for parasite detection in the tissues. In the symptomatic group, assay sensitivity was 75.61% for direct parasite search on Diff-Quick-stained FNAs, 92.68% for direct immunofluorescence, 92.68% for immunocytochemistry and 100% for PCR; the corresponding values in the other clinical groups were: 32, 60, 76 and 96% (oligosymptomatic), and 39.13, 73.91, 100 and 95.65% (asymptomatic). Results of the control animals from the CanL non-endemic area were all negative, indicating that the methods used were 100% specific.  相似文献   

6.
During the 2004 and 2005 sand fly seasons, we evaluated the efficacy of a 65% spot-on solution of permethrin (Exspot, Schering & Plough) and deltamethrin-impregnated collar (Scalibor, Intervet) in reducing Leishmania infantum infection, in a canine leishmaniasis (CanL) endemic region (Liguria) in Italy. Immunofluorescent assay (IFA) revealed that three of 120 dogs (2.5%) treated with a 65% spot-on solution of permethrin, as three of 119 dogs (2.5%) treated with deltamethrin-impregnated collar have shown seroconversion after sand fly season. On the contrary, seroconversion was 15% in 188 untreated control dogs. Treatment reduced the risk of infection by 84%. The difference in treated dogs and control ones is highly significant (chi2 = 12.4; P = 0.0004). Our results show that treatment with 65% spot-on solution of permethrin and the deltamethrin-impregnated collar are effective in reducing the risk of acquiring L. infantum infection.  相似文献   

7.
Angiostrongylus vasorum, French heartworm, is a metastrongloid parasite found in the pulmonary arteries and right ventricle of wild and domestic canids and various other animals. The natural definitive hosts are species of foxes. The geographic distribution of the parasite includes various countries of Europe, Africa, South America, and North America. Angiostrongylosis is considered an emerging disease in dogs in Europe. In North America, autochthonous A. vasorum infection occurs only in the Canadian province of Newfoundland-Labrador. Computer modeling suggests there is a high probability that A. vasorum will spread to other parts of North America and will likely become endemic in the eastern half of the continent and in the states and provinces along the western coast. Animals acquire infection by the ingestion of gastropod or frog intermediate hosts that carry the infective 3rd-stage larvae. Frogs can also serve as paratenic hosts. Definitive antemortem diagnosis is by detection of L(1) in feces, sputum, or bronchoalveolar lavage samples. Baermann fecal examination is the most reliable method for fecal detection. However, false negative results can occur due to the typical erratic/sporadic fecal larval shedding pattern of A. vasorum. Recently, promising new methods for A. vasorum infection diagnosis have been reported involving polymerase chain reaction of blood and fecal samples and a sandwich ELISA for detection of circulating worm excretory/secretory antigen. Current treatment options include moxidectin, milbemycin oxime, and fenbendazole.  相似文献   

8.
Infections of domesticated dogs by a worldwide parasitic nematode Filaroides osleri (Oslerus osleri) lead to verminous tracheobronchitis that are often misdiagnosed clinically as kennel cough, due to infection with the bacterium Bordetella bronchiseptica. Diagnosis of two canine cases in Wyoming, USA prompted a search of the literature of canid infections in North America. Infections of domestic dogs are reported in nine US states and four Canadian provinces. Dogs of multiple breeds and both sexes were infected. Most were two years old or younger at diagnosis. Anthelmintic treatments were effective in relieving clinical symptoms, as well as causing resolution of tracheobronchial nodules. Other canid species, including coyotes (Canis latrans) and wolves (Canis lupus), have been infected across North America with a prevalence of 23% and 4%, respectively. Infection with F. osleri should be included in the differential diagnosis of infectious tracheobronchitis of dogs. It can be confirmed most readily by endoscopic detection of distinctive submucosal parasite-filled nodules, combined with histological examination of endoscopic biopsies.  相似文献   

9.
An epidemiological survey on canine leishmaniasis (CanL) was performed during a 3-year period (2007-2009) in a public kennel of the Bologna province. The presence of the disease was shown in the canine population for the first time in 2007 by indirect fluorescent antibody test (IFAT). The parasite circulation was confirmed also by direct diagnostic tools, as PCR, cytology and cultural method, performed on different bioptic materials. The parasite was isolated and identified as Leishmania infantum zymodeme MON 1. The serological monitoring was performed also in 2008 and 2009 on animals that previously showed negative or uncertain results. The incidence values calculated by significant seroconversions in IFAT titre ≥ 1/160, ranged between 4.9% and 6.6%, indicating a stable focus of leishmaniasis. The entomological survey, performed by sticky and CO(2)-baited traps in 2008, showed the presence of the vector Phlebotomus perfiliewi. This study allowed us to identify a stable focus of CanL in an area that was not considered eco-compatible with the presence of the vector and infection. Our results confirm the northward spread of CanL towards areas not previously affected by autochthonous foci.  相似文献   

10.
Monoclonal Gammopathy in a Dog With Visceral Leishmaniasis   总被引:1,自引:0,他引:1  
One dog with visceral leishmaniasis associated with monoclonal gammopathy is described. Most dogs with visceral leishmaniasis present with hyperproteinemia due to a polyclonal gammopathy, but the possibility of monoclonal gammopathy must be considered. Because dogs accompany their owners when they travel, the diagnosis of leishmaniasis should be considered if an animal with monoclonal gammopathy has visited an area where the disease is endemic. The observation of Leishmania in the macrophages of a bone marrow, lymph node smear, or skin biopsy specimen is diagnostic.  相似文献   

11.
Canine leishmaniosis (CanL) caused by the parasite Leishmania infantum is a systemic disease with variable clinical signs. The disease is endemic in the Mediterranean countries and dogs are the main domestic reservoir of the parasite. The quite complicated immune response against the parasite is crucial for the evolution of CanL infection with the skin playing a major role in its immunopathogenesis.After the inoculation of Leishmania promastigotes into the dermis by sand fly bites, complement factors, Langerhan's cells, neutrophils, fibroblasts and keratinocytes are involved in the activation of the innate arm of the skin immune system, with the macrophages and dendritic cells to play a major key role.The effective activation of cellular immunity is the cornerstone of dog's resistance against the parasite. Promastigotes reaching the dermis are engulfed, processed and transferred by APCs to draining lymph nodes to stimulate naïve T-cells for proliferation and differentiation into armed effector T-cells. Th1 cells activate the infected macrophages to kill Leishmania, whereas Th2 cells divert the immune response to humoral immunity and down regulation of cellular immunity with Th1 cell anergy. Inhibition of co-stimulatory molecules expression by infected macrophages contributes to T-cell anergy. In canine subclinical infections cutaneous lymphocytic infiltrate and parasites are absent, as opposed to dogs with clinical leishmaniosis. CD8+ cells constitute a significant population of cellular immunity in CanL since they outnumber CD4+ cells in the dermis, producing IFN-γ in sub clinically infected dogs and high levels of IL-4 in dogs with clinical leishmaniosis.Numerous B-lymphocytes have been shown to heavily infiltrate the dermis at least in exfoliative dermatitis in CanL. A mixed Th1/Th2 cytokine profile has been found in the dermis of naturally infected with L. infantum dogs. In the skin of dogs with clinical leishmaniosis, where plasma cells outnumber T lymphocytes in the dermal infiltrate, there is an overproduction of IL-4, IL-13 and TNF-α leading to Th2-biased humoral immune response. The issue of humoral immunity polarization in CanL remains controversial. Much still needs to be learned about other mechanisms underlying the complex interaction between the skin immune system and the parasite.  相似文献   

12.
BACKGROUND: Canine leishmaniasis (CanL) is a common cause of epistaxis in dogs residing in endemic areas. The pathogenesis of CanL-associated epistaxis has not been fully explored because of the limited number of cases reported so far. HYPOTHESIS: Epistaxis in CanL could be attributed to more than 1 pathomechanism such as hemostatic dysfunction, biochemical abnormalities, chronic rhinitis, and coinfections occurring in various combinations. ANIMALS: Fifty-one dogs with natural CanL. METHODS: The allocation of 51 dogs in this cross-sectional study was based on the presence (n = 24) or absence (n = 27) of epistaxis. The potential associations among epistaxis and concurrent infections (Ehrlichia canis, Bartonella spp., and Aspergillus spp.), biochemical and hemostatic abnormalities, and nasal histopathology were investigated. RESULTS: Hypergammaglobulinemia (P= .044), increased serum viscosity (P= .038), decreased platelet aggregation response to collagen (P= .042), and nasal mucosa ulceration (P= .039) were more common in the dogs with epistaxis than in those without epistaxis. The other significant differences between the 2 groups involved total serum protein (P= .029) and gamma-globulin (P= .013) concentrations, which were higher, and the percentage platelet aggregation to collagen, which was lower (P= .012) in the epistaxis dogs. CLINICAL IMPORTANCE: CanL-associated epistaxis appears to be the result of multiple and variable pathogenetic factors such as thrombocytopathy, hyperglobulinemia-induced serum hyperviscosity, and nasal mucosa ulceration.  相似文献   

13.
Canine leishmaniosis (CanL) is an important zoonotic disease; however, the efficacy of available vaccines for the prevention of naturally-occurring Leishmania infantum (L. infantum) infection in dogs remains unclear.  相似文献   

14.
Although endemic throughout much of the world, autochthonous visceral leishmaniasis has been reported on only 3 previous occasions in North America. After diagnosis of visceral leishmaniasis in 4 foxhounds from a kennel in Dutchess County, New York (index kennel), serum and ethylenediamine-tetraacetic acid (EDTA)-anticoagulated blood were collected from the remaining 108 American or cross-bred foxhounds in the index kennel and from 30 Beagles and Basset Hounds that were periodically housed in the index kennel. Samples were analyzed for antibodies to or DNA of tickborne disease pathogens and Leishmania spp. Most dogs had antibodies to Rickettsia spp., Ehrlichia spp., Babesia spp., or some combination of these pathogens but not to Bartonella vinsonii (berkhoffi). However, DNA of rickettsial, ehrlichial, or babesial agents was detected in only 9 dogs. Visceral leishmaniasis was diagnosed in 46 of 112 (41%) foxhounds from the index kennel but was not diagnosed in any of the Beagles and Basset Hounds. A positive Leishmania status was defined by 1 or more of the following criteria: a Leishmania antibody titer > or = 1:64, positive Leishmania polymerase chain reaction (PCR), positive Leishmania culture, or identification of Leishmania amastigotes by cytology or histopathology. The species and zymodeme of Leishmania that infected the foxhounds was determined to be Leishmania infantum MON-1 by isoenzyme electrophoresis. Foxhounds that were > 18 months of age or that had traveled to the southeastern United States were more likely to be diagnosed with visceral leishmaniasis. Transmission of Leishmania spp. in kennel outbreaks may involve exposure to an insect vector, direct transmission, or vertical transmission.  相似文献   

15.
Human visceral leishmaniasis (HVL) is endemic in the tropical and sub-tropical regions of Africa, Asia, the Mediterranean, Southern Europe and South and Central America, with approximately 500,000 new cases reported annually. As dogs are considered to be the major reservoirs for HVL, the accurate diagnosis of disease in these animals is important. Diagnosis of canine visceral leishmaniasis (CVL) is performed mainly by direct parasitological methods that can yield false-negative results, either because of the very low number of Leishmania spp. organisms in clinical samples (bone marrow and lymph nodes) or because morphological identification is difficult. In addition, these methods are invasive. Conventional serological techniques are limited by cross-reactivity with other parasitic diseases and because several technical procedures have not been standardised. The development of polymerase chain reaction based approaches and immunoassays based on the use of recombinant antigens aimed at improving the sensitivity and specificity of CVL diagnosis is discussed.  相似文献   

16.
Leishmania chagasi is the causative agent of visceral leishmaniasis in both humans and dogs in the New World. The dog is the main domestic reservoir and its infection displays different clinical presentations, from asymptomatic to severe disease. Macrophages play an important role in the control of Leishmania infection. Although it is not an area of intense study, some data suggest a role for canine macrophages in parasite killing by a NO-dependent mechanism. It has been proposed that control of human disease could be possible with the development of an effective vaccine against canine visceral leishmaniasis. Development of a rapid in vitro test to predict animal responses to Leishmania infection or vaccination should be helpful. In this study, an in vitro model was established to test whether peripheral blood mononuclear cell (PBMC) supernatants from dogs immunized with promastigote lysates and infected with L. chagasi promastigotes could stimulate macrophages from healthy dogs in order to control parasite infection. PBMC from a majority of the immunized and experimentally infected dogs expressed IFN-gamma mRNA and secreted IFN-gamma when stimulated with soluble L. chagasi antigen (SLA) in vitro. Additionally, the supernatants from stimulated PBMC were able to reduce the percentage of infected donor macrophages. The results also indicate that parasite killing in this system is dependent on NO, since aminoguanidine (AMG) reversed this effect. This in vitro test appears to be useful for screening animal responses to parasite inoculation as well as studying the lymphocyte effector mechanisms involved in pathogen killing by canine macrophages.  相似文献   

17.
Objective – The aim of this article is to review Angiostrongylus vasorum infection in dogs, including the life cycle, signalment, clinical signs, diagnosis, and treatment. Apparent changes in the epidemiology of this unique parasite are considered, alongside information available regarding its recent geographic spread.
Etiology – A. vasorum is a metastrongyloid parasite capable of causing an array of clinical problems in dogs, including cardiorespiratory, coagulopathic, and neurologic signs. Currently, the parasite has a worldwide distribution; however, it usually arises in small pockets of enzootic foci. Recent reports suggest a changing distribution of this parasite, which has renewed interest in its epidemiology and in the risk of expansion to new areas including mainland North America.
Diagnosis – A definitive diagnosis of angiostrongylosis is usually made using the modified Baermann technique either using feces or tracheobronchial secretions; however, this review also discusses novel methods such as serologic and molecular techniques.
Therapy – Once a diagnosis of angiostrongylosis is made, prompt treatment should follow with anthelmintic drugs (such as moxidectin/imidacloprid, milbemycin oxime, or fenbendazole) and supportive care dependent upon the patient's clinical signs. Currently, there is no proven prophylactic regime.
Prognosis – The prognosis appears to be very dependent upon the severity of clinical signs at presentation. A. vasorum can be fatal and death may be sudden. However, if a prompt diagnosis is made and appropriate treatment is administered complete clinical resolution is possible.  相似文献   

18.
Leishmaniasis is a potentially fatal chronic protozoan disease in human, canine and rodent species. The infection by Leishmania is endemic in the Mediterranean Sea region, Africa, Asia and South America. Canine visceral leishmaniasis (CanVL) is a systemic disease caused by Leishmania infantum and Leishmania chagasi from the Leishmania donovani complex group. The blood glutathione (GSH), plasma malondialdehyde (MDA), ascorbic acid (AA), beta-carotene, retinol and ceruloplasmin levels of dogs with CanVL were investigated to establish the status of the antioxidant defense mechanism in the infected animals. Dogs diagnosed as CanVL with amastigotes in lymph node smear examination and/or antibody titers > or = 128 were used as subjects, while those with no serological response against leishmaniasis were used as healthy controls. The glutathione and retinol amounts were decreased although not significantly (p > 0.05), but the MDA levels were significantly higher in dogs with VL, suggesting increased lipid peroxidation.  相似文献   

19.
Canine leishmaniasis caused by Leishmania infantum is endemic in the foxhound population in North America. Studies of canine leishmaniasis in the Mediterranean basin indicate a role for both CD4+ and CD8+ lymphocytes with clinical illness and in asymptomatic dogs. Limited information is available on the strain of L. infantum infecting foxhounds in North America. The present study investigated changes in cellular immune responses in dogs experimentally infected with 1x10(7) (low dose, LD; N=4) or 2x10(8) (high dose, HD; N=4) promastigotes of a United States isolate of L. infantum and control dogs (N=2) for 72 weeks. Density gradient separation was used to enrich for peripheral blood lymphocytes from canine blood. Lymphocyte subsets (CD4+ and CD8+) were quantified by flow cytometric analysis. Lymphocyte population expression levels over the course of the present study were compared to clinical status of the dog and antibody responses in infected and control dogs. No significant differences (P>0.05) were observed in either CD4+ or CD8+ lymphocyte expression in of the groups over the experimental period. This study suggests that the cellular immune responses to North American L. infantum in experimentally infected dogs may differ from other strains of L. infantum.  相似文献   

20.
Human visceral leishmaniasis, one of the most important zoonoses, is caused by the protozoa Leishmania chagasi (syn. L. infantum) and is present as a fatal disease common in South America and Europe where dogs and wild canids are the main reservoirs. A vaccine against visceral leishmaniasis would be an important tool in the control of this disease in dogs. Although the current strategies for vaccination against leishmaniasis are based on the use of recombinant antigens, killed vaccines are still attractive in terms of stability of their biochemical composition and antigenicity, cost, and safety. Here we evaluate the immunogenicity of a whole parasite vaccine as a promising candidate against canine leishmaniasis, demonstrated by cellular reactivity, changes in the cellular profile of the peripheral blood and by the differential production of immunoglobulins. Our results showed that immunization elicited mainly a strong cellular reactivity and increase in T-lymphocytes, particularly the subpopulation CD8(+) that would be related to the control of tissue parasitism. In addition, a higher production of anti-Leishmania total IgG, characterized by mixed isotypes profile (IgG1 and IgG2), was demonstrated.  相似文献   

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