Feline leishmaniosis due to Leishmania infantum (syn. L. chagasi)

Από τις αρχές του 20ου αιώνα έχουν καταγραφεί, σε διάφορες περιοχές, περιστατικά φυσικής μόλυνσης τηςγάτας από οκτώ τουλάχιστον είδη του γένους Leishmania. Για τις μεσογειακές χώρες, ιδιαίτερο ενδιαφέρον έχει η μόλυνσηαπό την L. infantum, που είναι το αίτιο της λεϊσμανίωσης του σκύλου και της σπλαγχνικής ή δερματικής λεϊσμανίασης τουανθρώπου και για τις οποίες η γάτα θα μπορούσε να αποτελεί «δευτερογενή δεξαμενή» του παρασίτου. Αν και το ποσοστότων μολυσμένων γατών μπορεί, σε ορισμένες περιπτώσεις, να ξεπερνά ακόμη και το 60%, τα συμπτωματικά ζώα είναι σπάνια,επειδή η γάτα είναι ανθεκτικότερη στη λεϊσμανίωση σε σύγκριση με το σκύλο. Οι μολυσμένες, όμως, γάτες ενδέχεται ναεμφανίσουν δερματικές και οφθαλμικές αλλοιώσεις ή/και συμπτώματα από διάφορα εσωτερικά όργανα. Τα έλκη και τα οζίδιαπου εντοπίζονται κατά κύριο λόγο στα βλεννογονοδερματικά όρια, το επιρρίνιο, το πρόσωπο και τα πτερύγια των αυτιώνείναι οι δερματικές εκείνες αλλοιώσεις που εμφανίζονται συχνότερα στην πράξη. Λιγότερο συχνές είναι η αποφολιδωτικήδερματίτιδα και η ποδοδερματίτιδα, ενώ άγνωστο παραμένει εάν για τις βλατίδες, τις εφελκίδες και την αλωπεκία, που έχουνπαρατηρηθεί σε ορισμένα μολυσμένα ζώα, θα μπορούσε πράγματι να ενοχοποιηθεί η λεϊσμανίωση. Στις οφθαλμικές αλλοιώσειςπεριλαμβάνονται η επιπεφυκίτιδα, η (ελκώδης) κερατίτιδα, η πρόσθια και οπίσθια ραγοειδίτιδα, η χοριοαμφιβληστροειδίτιδακαι η πανοφθαλμίτιδα. Από τα συμπτώματα και τις παθολογικές καταστάσεις από τα εσωτερικά όργανα, τα μόνα που θαμπορούσαν να αποδοθούν στη λεϊσμανίωση της γάτας είναι η περιφερική λεμφαδενομεγαλία, η σπληνομεγαλία, η ηπατομεγαλίακαι η νεφρίτιδα που ενδέχεται να οδηγήσει σε χρόνια νεφρική ανεπάρκεια. Από τα εργαστηριακά ευρήματα, το πλέον χαρακτηριστικόείναι η υπερσφαιριναιμία που συνήθως είναι πολυκλωνική και σπανιότερα μονοκλωνική. Η λεϊσμανίωση της γάταςσυχνά συνυπάρχει με πολλά άλλα νοσήματα και παθήσεις, που θα μπορούσαν να μεταβάλουν την κλινική εικόνα και ενδεχομένωςνα καταστείλουν το ανοσοποιητικό σύστημα των μολυσμένων ζώων. Όπως και στο σκύλο, η διάγνωση της λεϊσμανίωσης στηγάτα στηρίζεται στην αλυσιδωτή αντίδραση της πολυμεράσης (PCR), την κυτταρολογική, ιστοπαθολογική και ανοσοϊστοχημικήεξέταση, την καλλιέργεια σε ειδικά υποστρώματα και τις ορολογικές εξετάσεις. Όλες οι παραπάνω διαγνωστικές μέθοδοιπαρουσιάζουν πλεονεκτήματα και μειονεκτήματα, ενώ η ευαισθησία τους ποικίλλει ανάλογα με το διαθέσιμο βιολογικό υλικόκαι την τεχνική που εφαρμόζεται κάθε φορά. Η κυτταρολογική, ιστοπαθολογική ή/και ανοσοϊστοχημική εξέταση από το μυελότων οστών, τα λεμφογάγγλια, τη σπλήνα, τις δερματικές και τις οφθαλμικές αλλοιώσεις στοχεύει στην ανίχνευση των αμαστιγοφόρων μορφών, που όταν βρεθούν, η μόλυνση αποδεικνύεται πέρα από κάθε αμφιβολία. Οι ορολογικές εξετάσεις, ανάλογαμε τη μεθοδολογία και το όριο διαχωρισμού, υποεκτιμούν ή υπερεκτιμούν την πραγματική συχνότητα της μόλυνσης σε γάτεςπου ζουν σε περιοχές στις οποίες η νόσος ενδημεί. Με την PCR, που ανιχνεύει το DNA του παρασίτου στο μυελό των οστών,τα λεμφογάγγλια, τη σπλήνα, το δέρμα και ενδεχομένως το περιφερικό αίμα, φαίνεται ότι εξυπηρετούνται καλύτερα οι επιζωοτιολογικες μελέτες. Μέχρι σήμερα η θεραπευτική αντιμετώπιση της λεϊσμανίωσης της γάτας στηρίζεται κυρίως στημακροχρόνια χορήγηση της αλλοπουρινόλης, σε συνδυασμό με τη θεραπεία των νοσημάτων και των παθήσεων που ενδεχομένωςσυνυπάρχουν.From the beginning of the 20th century, feline infections by at least eight different Leishmania species have been sporadically reported, worldwide. In the Mediterranean countries, feline infection imposed by L. infantum, the aetiological agent of canine leishmaniosis and human visceral and cutaneous leishmaniasis, is of particular importance, because cats may represent a "secondary reservoir" of the parasite in the nature. Although the prevalence of the infection may be as high as 60%, most infected cats are resistant and remain asymptomatic, while only occasionally, they may present cutaneous and/or ocular lesions, and perhaps systemic clinical signs. In feline leishmaniosis, ulcers and nodules, usually localized at mucocutaneous junctions, planum nasale, face and ear pinnae, constitute the mainstream of cutaneous lesions. In a small number of cases, exfoliative dermatitis and pododermatitis have been noted, whereas a cause-and-effect relationship, between feline leishmaniosis and the presence of papules, crusts and generalized alopecia remains speculative. Ocular lesions, such as those associated with conjunctivitis, (ulcerative) keratitis, posterior or anterior uveitis, chorioretinitis and panopthalmitis are relatively common. The only systemic signs that have been constantly associated with feline leishmaniosis are peripheral lymphadenomegaly, splenomegaly, hepatomegaly and chronic nephritis that may lead to chronic renal failure. The most consistent laboratory abnormality is hyperglobulinaemia that is usually polyclonal. Feline leishmaniosis can co-exist with various other infectious and non-infectious diseases that may alter its clinical picture and/or influence the immunological response of the infected cat. Diagnosis is usually based on the results of cytology,histopathology, immunohistochemistry, culture, serology and polymerase chain reaction (PCR). Apart from the advantages and limitations inherent to each of these methods, their diagnostic value depends on many factors, such as the biological sample being used, the reagents and the particular technique employed. Leishmania amastigotes can be detected by applying bone marrow, lymph node, spleen, cutaneous and ocular cytology, histopathology, and/or immunohistochemistry, which are 100% specific. Serology may underestimate or even overestimate the frequency of the infection in the endemic areas, depending on the methodology and the cut-off value, whereas PCR, that can be performed on the tissues mentioned before, plus the peripheral blood may be a better option for epidemiological studies. Although a uniformly effective treatment for symptomatic cats has not been established yet, long-term allopurinol administration, along with the management of any concurrent diseases, is the only treatment to suggest at moment

Development of a LAMP assay for detection of Leishmania infantum infection in dogs using conjunctival swab samples

Background: Leishmania infantum infections in dogs play a crucial role in the transmission of pathogens causing visceral leishmaniasis to humans in the Gansu province, northwest China. To be able to control zoonotic transmission of the parasite to humans, a non-invasive loop-mediated isothermal amplification (LAMP) assay to specifically detect L. infantum infections in dogs was developed. Methods: The primers used in the LAMP assay were designed to target kinetoplast DNA minicircle sequences of the L. infantum isolate MCAN/CN/90/SC and tested using DNA isolated from promastigotes of different Leishmania species. The LAMP assay was evaluated with conjunctional swab samples obtained from 111 and 33 dogs living in an endemic and a non-endemic region of zoonotic visceral leishmaniasis in the Gansu province, respectively. The LAMP assay was also compared with conventional PCR, ELISA and microscopy using conjunctional swab, serum and bone marrow samples from the dogs, respectively. Results: The LAMP assay detected 1 fg of L. infantum DNA purified from cultured promastigotes which was 10-fold more sensitive than a conventional PCR test using Leishmania genus-specific primers. No cross reaction was observed with DNA isolated from promastigotes of L. donovani, L. major, L. tropica, and L. braziliensis, and the L. infantum reference strain MHOM/TN/80/IPT1. The L. infantum-positive rates obtained for field-collected samples were 61.3%, 58.6%, 40.5% and 10.8% by LAMP, PCR, ELISA and microscopy, respectively. As only one out of the 33 samples from control dogs from the non-endemic region of zoonotic visceral leishmaniasis was positive by the LAMP assay and the PCR test, the observed true negative rate (specificity) was 97% for both methods. Conclusion: This study has shown that the non-invasive, conjunctional swab-based LAMP assay developed was more sensitive in the detection of leishmaniasis in dogs than PCR, ELISA and microscopy. The findings indicate that the LAMP assay is a sensitive and specific method for the field surveillance of domestic dogs, particularly of asymptomatic canines, in ZVL-endemic areas in western China

Canine leishmaniasis: the key points for qPCR result interpretation

Background: Diagnosis and follow up of CanL is difficult since the range of clinical signs is varied and seroprevalence is high in endemic areas. The aims of this study were: i) demonstrate the advantages of Leishmania qPCR to diagnose and control CanL and highlight its prognostic value and ii) propose guidelines for tissue selection and infection monitoring. Findings: This study included 710 dogs living in an endemic area of leishmaniasis. Forty percent (285/710) exhibited clinical signs consistent with CanL. Infection was detected in 36.3% (258/710) of the dogs of which 4.5% (32/710) were detected by qPCR, 16.2% (115/710) detected by ELISA and 15.6% (111/710) tested positive for both tests. Only 17.9% (127/710) of the dogs were classified sick (affected) with CanL. All symptomatic dogs with medium or high ELISA titers were qPCR-positive in blood samples. All dogs with inconclusive or low ELISA results with high or medium qPCR parasitemia values developed the disease. Seventy one percent of asymptomatic ELISA-positive dogs confirmed by qPCR (medium to high parasitemia) developed the disease. Bone marrow or lymph node aspirate should be selected to ensure the absence of the parasite in asymptomatic dogs: 100-1,000 parasites/ml in bone marrow are detectable in blood, whereas lower parasite loads are usually negative. Almost 10% of negative samples in blood were positive in conjunctival swabs. Conclusions: Because qPCR allows parasite quantification, it is an effective tool to confirm a diagnosis of CanL in (i) cases of inconclusive ELISA results, (ii) when the dog has not yet seroconverted, or (iii) for treatment monitoring

LeishVet guidelines for the practical management of canine leishmaniosis

The LeishVet group has formed recommendations designed primarily to help the veterinary clinician in the management of canine leishmaniosis. The complexity of this zoonotic infection and the wide range of its clinical manifestations, from inapparent infection to severe disease, make the management of canine leishmaniosis challenging. The recommendations were constructed by combining a comprehensive review of evidence-based studies, extensive clinical experience and critical consensus opinion discussions. The guidelines presented here in a short version with graphical topic displays suggest standardized and rational approaches to the diagnosis, treatment, follow-up, control and prevention of canine leishmaniosis. A staging system that divides the disease into four stages is aimed at assisting the clinician in determining the appropriate therapy, forecasting prognosis, and implementing follow-up steps required for the management of the leishmaniosis patient

Fleas as parasites of the family Canidae

Historically, flea-borne diseases are among the most important medical diseases of humans. Plague and murine typhus are known for centuries while the last years brought some new flea-transmitted pathogens, like R. felis and Bartonella henselae. Dogs may play an essential or an accidental role in the natural transmission cycle of flea-borne pathogens. They support the growth of some of the pathogens or they serve as transport vehicles for infected fleas between their natural reservoirs and humans. More than 15 different flea species have been described in domestic dogs thus far. Several other species have been found to be associated with wild canids. Fleas found on dogs originate from rodents, birds, insectivores and from other Carnivora. Dogs therefore may serve as ideal bridging hosts for the introduction of flea-borne diseases from nature to home. In addition to their role as ectoparasites they cause nuisance for humans and animals and may be the cause for severe allergic reactions

Prevalence of Dirofilaria immitis, Ehrlichia canis, Borrelia burgdorferi sensu lato, Anaplasma spp. and Leishmania infantum in apparently healthy and CVBD-suspect dogs in Portugal - a national serological study

<p>Abstract</p> <p>Background</p> <p>Canine vector-borne diseases (CVBDs) are caused by a wide range of pathogens transmitted to dogs by arthropods including ticks and insects. Many CVBD-agents are of zoonotic concern, with dogs potentially serving as reservoirs and sentinels for human infections. The present study aimed at assessing the seroprevalence of infection with or exposure to <it>Dirofilaria immitis, Ehrlichia canis, Borrelia burgdorferi </it>sensu lato, <it>Anaplasma </it>spp. and <it>Leishmania infantum </it>in dogs in Portugal.</p> <p>Methods</p> <p>Based on 120 veterinary medical centres from all the regions of mainland and insular Portugal, 557 apparently healthy and 628 CVBD-suspect dogs were sampled. Serum, plasma or whole blood was tested for qualitative detection of <it>D. immitis </it>antigen and antibodies to <it>E. canis, B. burgdorferi </it>s. l., <it>Anaplasma </it>spp. and <it>L. infantum </it>with two commercial in-clinic enzyme-linked immunosorbent assay kits. Odds ratios (OR) were calculated by logistic regression analysis to identify independent risk factors of exposure to the vector-borne agents.</p> <p>Results</p> <p>Total positivity levels to <it>D. immitis, E. canis, B. burgdorferi, Anaplasma </it>spp., <it>L. infantum</it>, one or more agents and mixed agents were 3.6%, 4.1%, 0.2%, 4.5%, 4.3%, 14.0% and 2.0% in the healthy group, and 8.9%, 16.4%, 0.5%, 9.2%, 25.2%, 46.3% and 11.6% in the clinically suspect group, respectively. Non-use of ectoparasiticides was a risk factor for positivity to one or more agents both in the apparently healthy (OR = 2.1) and CVBD-suspect (OR = 1.5) dogs. Seropositivity to <it>L. infantum </it>(OR = 7.6), <it>E. canis </it>(OR = 4.1) and <it>D. immitis </it>(OR = 2.4) were identified as risk factors for the presence of clinical signs compatible with CVBDs. Positivity to mixed agents was not found to be a risk factor for disease.</p> <p>Conclusions</p> <p>Dogs in Portugal are at risk of becoming infected with vector-borne pathogens, some of which are of zoonotic concern. CVBDs should be considered by practitioners and prophylactic measures must be put in place to protect dogs and limit the risk of transmission of vector-borne agents to humans. This study is expected to give veterinary and public health authorities an increased awareness about CVBDs in Portugal and to serve as a reference for future investigations and control actions.</p

Ectoparasitos de cães no ambiente doméstico da vertente Caribe, Costa Rica

Reports on ectoparasites on dogs in Central America are scarce. The aim of this study was to identify flea, louse and tick species infesting dogs in home environments on the Caribbean slope of Costa Rica, and determine their frequency and coexistence. Ectoparasites were collected from dogs in 83 rural homes at five study sites. Specimens were identified and separated according to species. Fleas were the most common ectoparasite (G = 22,217, DF = 8, p = 0.004). Ctenocephalides felis and Pulex simulans were found in 83% and 55% of the homes with ectoparasites, respectively. Trichodectes canis (13%), Heterodoxus spiniger (10%), Rhipicephalus sanguineus (18%), Rhipicephalus (Boophilus) microplus (5%) and Amblyomma ovale (8%) were also present. More than one species was collected in most cases (66%), and the most common combination was C. felis and P. simulans (59% of homes with fleas). The high frequency of P. simulans emphasizes the need for adequate identification. This was the first study involving different ectoparasites of dogs in Costa Rica, as well as the first report of T.  canis in this country. The relative frequency and coexistence of these ectoparasites in the home environment may have implications for animal and human health.Relatos de ectoparasitos em cães da América Central são escassos. O objetivo deste estudo foi identificar espécies de pulgas, piolhos e carrapatos que infestam os cães no ambiente doméstico da vertente Caribe da Costa Rica, determinando sua frequência e coexistência. Foram coletados ectoparasitos de cães em 83 casas rurais de cinco sítios do estudo. Os indivíduos foram separados e identificados. Os ectoparasitos mais comuns foram as pulgas (G = 22.217, DF = 8, p = 0.004). Ctenocephalides felis e Pulex simulans foram observados em 83% e 55% das moradias com ectoparasitos, respectivamente. Da mesma forma também foram observados Trichodectes canis (13%), Heterodoxus spiniger (10%), Rhipicephalus sanguineus (18%), Rhipicephalus (Boophilus) microplus (5%) e Amblyomma ovale (8%). Na maioria dos casos, mais de uma espécie foi achada (66%), sendo que a combinação mais comum foi C. felis e P. simulans (59% de moradias com pulgas). A frequência alta de P. simulans ressalta a necessidade de sua adequada identificação. Este é o primeiro estudo que envolve diferentes ectoparasitas de cães na Costa Rica, da mesma forma, é o primeiro relato de T.  canis no país. A frequência relativa e coexistência destes ectoparasitos no ambiente domiciliar poderiam ter implicações na saúde animal e humana.Universidad de Costa Rica/[803-A8-127]/UCR/Costa Rica/[9-N-2008]/NeTropica/Costa RicaUCR::Vicerrectoría de Investigación::Unidades de Investigación::Ciencias de la Salud::Centro de Investigación en Enfermedades Tropicales (CIET)UCR::Vicerrectoría de Investigación::Unidades de Investigación::Ciencias Básicas::Centro de Investigación en Estructuras Microscópicas (CIEMIC)UCR::Vicerrectoría de Docencia::Ciencias Básicas::Facultad de Ciencias::Escuela de Biologí