Paola Paradies

Diagnosis and risk factors of Aelurostrongylus abstrusus (Nematoda, Strongylida) infection in cats from Italy

Aelurostrongylus abstrusus (Nematoda, Strongylida) in cats and associated risk factors have been investigated by classical coprology in central (site A) and southern (site B) Italy, i.e. by floatations with sugar and zinc sulphate solutions and a Baermann technique. Overall, 227 individual stool samples (i.e. 162 from site A and 65 from site B) were processed and risk factors were related to infection by binary logistic multiple-regression models. The presence of A. abstrusus was used as the dependent variable and the epidemiological data as independent variables. Twenty-eight (17.3%) and 12 (18.5%) cats were positive for A. abstrusus in sites A and B, respectively, both using the Baermann and flotation with zinc sulphate solution methods. Six and three (from site A and B, respectively) of the infected cats were negative for A. abstrusus when faeces were processed with sugar solution. Stray and free-ranging (P=0.357), young cats (P=0.008) and the presence of respiratory symptoms (P=0.000) were risk factors for A. abstrusus infection. The results suggest that A. abstrusus is spread in Italy. Furthermore, these results possibly include infection in the differential diagnosis of feline respiratory diseases and offer a correct diagnostic approach by using either a Baermann method or flotation with zinc sulphate solution in suspected cases.

Toward Diagnosing Leishmania infantum Infection in Asymptomatic Dogs in an Area Where Leishmaniasis Is Endemic

ABSTRACT The most frequently used diagnostic methods were compared in a longitudinal survey with Leishmania infantum-infected asymptomatic dogs from an area of Italy where leishmaniasis is endemic. In February and March 2005, 845 asymptomatic dogs were tested by an immunofluorescence antibody test (IFAT), a dipstick assay (DS), and an enzyme-linked immunosorbent assay (ELISA) for L. infantum and by IFAT for Ehrlichia canis. Dogs seronegative for L. infantum were further parasitologically evaluated by microscopic examination of lymph node tissues and PCR of skin samples. A total of 204 animals both serologically and parasitologically negative for L. infantum at the first sampling were enrolled in the trial and were further examined for canine leishmaniasis (CanL) and canine monocytic ehrlichiosis in November 2005 (i.e., the end of the first sandfly season) and March 2006 and 2007 (1- and 2-year follow-ups, respectively). At the initial screening, the overall rates of L. infantum seroprevalence were 9.5% by IFAT, 17.1% by ELISA, and 9.8% by DS and the overall rate of E. canis seroprevalence was 15%. The rates of concordance between the results of IFAT and DS were almost equal, whereas the rate of concordance between the results of IFAT and DS and those of the ELISA was lower. The results of the annual incidence of Leishmania infection were variable, depending on the test employed, with the highest values registered for PCR (i.e., 5.7% and 11.4% at the 1- and 2-year follow-ups, respectively), followed by ELISA, IFAT, and DS. Over the 2 years of observation, 55 animals (i.e., 26.9%) became positive for L. infantum by one or more diagnostic tests at different follow-up times, with 12.7% showing clinical signs related to CanL, while the remaining 87.3% were asymptomatic. A diagnostic scheme for assessment of the L. infantum infection status in asymptomatic dogs is suggested.

Application of 10% imidacloprid/50% permethrin to prevent Ehrlichia canis exposure in dogs under natural conditions

Canine monocytic ehrlichiosis (CME) caused by Ehrlichia canis is the most known canine tick-borne disease (TBD) spread throughout the world. Preventing tick bites is a priority to reduce the risk of TBDs and it was the aim of the present study to evaluate the efficacy of a combination of imidacloprid 10% and permethrin 50% (ImPer) (Advantix; Bayer AG, Germany) in a spot-on formulation to control CME under field conditions. On January-March 2005, 845 dogs from two kennels in southern Italy (kennels of Bari (KB)- and Ginosa (KG)), with a history of tick infestation were initially tested by serology and PCR assay for E. canis infection. Data on Leishmania infantum infection were also available from a previous study carried out on the same dog population. One hundred twenty-six dogs (14.9%) presented anti-E. canis antibodies with a relative prevalence of 15.6% (n=65 dogs in KB) and 14.2% (n=61 dogs in KG). Five hundred thirty-five animals found negative both for E. canis and L. infantum infections were enrolled in three groups (Group A--treated with ImPer once a month; Group B--treated every 2 weeks; and Group C--untreated control animals) and monitored for E. canis infection by serology and PCR in November 2005 (first follow-up) and in March 2006 (second follow-up). The E. canis infection was serologically revealed, at the first and/or second follow-up, in 26 animals from Group C in KB and KG (mean incidence density rate (IDR), 13.24%) while in none of the animals from Group A (KB and KG) and only in one animal from Group B (IDR 1.13%) in KG. The final protection efficacy of ImPer ranged from 95.57% to 100% in Groups B and A. At PCR only 15 dogs from KG were positive for Rickettsiales only at the first follow-up and at the sequence analysis two (both in Group C) revealed 100% homology with E. canis sequences while 13 with Anaplasma platys. Four out of 13 A. platys PCR-positive dogs were also seropositive for E. canis at one or both follow-ups. ImPer, by virtue of its repellent and acaricidal activity against ticks, has been shown to be efficacious to prevent E. canis infection in treated dogs living under natural conditions in endemic areas.

Haemothorax associated with Angiostrongylus vasorum infection in a dog

Angiostrongylosis was diagnosed in a dog presenting with haemothorax on the basis of detection of Angiostrongylus vasorum first-stage larvae both in the pleural effusion and in faeces. A one-year-old, male, mixed-breed dog was presented with fever, depression and persistent cough of one months duration. Clinical examination revealed temperature of 39.5 degrees C, loud bronchovesicular sounds on thoracic auscultation and attenuated cardiac sounds. Thoracic radiographs showed a moderate bilateral pleural effusion and a diffuse interstitial pulmonary pattern, with an alveolar pattern in one lobe. Routine haematology revealed anaemia and leucocytosis with eosinophilia, basophilia and thrombocytopenia. Coagulation assays showed a consumptive coagulopathy resembling disseminated intravascular coagulation. The relationship between haemothorax and the presence of A vasorum larvae in the pleural effusion is discussed. The dog was successfully treated with fenbendazole until negative for larvae on faecal examination. This case report indicates that A vasorum infection should be considered as a possible aetiological cause of haemothorax in dogs.

Cytokine expression in dogs with natural Leishmania infantum infection

The aim of this study was to evaluate cytokine expression in 22 Leishmania infantum naturally infected dogs, in order to correlate this parameter with the clinical status of infected animals. After 4 and 8 months from the first diagnosis of Leishmania infection, clinical and laboratory examination of dogs was performed and peripheral blood mononuclear cells (PBMC) were isolated. The cytokine profile was analysed in terms of IFN-gamma, IL-4, IL-10 and TNF-alpha mRNA expression in cultured PBMC by a semi-quantitative reverse transcriptase-PCR. Thirteen out of 22 Leishmania-infected dogs remained asymptomatic in the follow-up, while 9 showed clinical signs of leishmaniasis. IL-4, IL-10, TNF-alpha and IFN-gamma mRNA levels were not significantly different in asymptomatic compared to symptomatic animals 4 months from the diagnosis of Leishmania infection, but were significantly higher in symptomatic versus asymptomatic dogs after 8 months from diagnosis. In addition, IL-4, IL-10 and TNF-alpha mRNA levels significantly increased only in symptomatic dogs at 8 months, in comparison to the levels found at 4 months. These results show a mixed Th1 and Th2 cytokine response in Leishmania-infected dogs, with higher cytokine expression in dogs with manifest clinical disease, during the second follow-up after 8 months from the first diagnosis of infection.

Recombinant K39 dipstick immunochromatographic test: a new tool for the serodiagnosis of canine leishmaniasis

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,a 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.

Atypical clinical presentation of coinfection with Ehrlichia, Babesia and Hepatozoon species in a dog.

TICKBORNE coinfections are commonly described in endemic areas ([Suksawat and others 2001b][1], [Zandvliet and others 2004][2]), although few clinical reports are available ([Meinkoth and others 1998][3], [Suksawat and others 2001a][4], [Tuttle and others 2003][5], [Mylonakis and others 2004][6]).

Clinical and laboratory monitoring of dogs naturally infected by Leishmania infantum

The clinical evolution of Leishmania infantum infection in dogs is largely influenced by the hosts individual immune response. Few studies have investigated the time course and clinical evolution of the infection both under experimental and natural conditions. In the present investigation, the time course of L. infantum infection was studied by monitoring clinical and laboratory features in naturally infected dogs sheltered in southern Italy. Twenty-three dogs that had one or more positive diagnostic tests for L. infantum were enrolled in the study and followed up every 4 months. A clinical score was assigned at each visit after assessing the presence of clinical signs suggestive of leishmaniosis. L. infantum-infected dogs were classified into three different categories based on their clinical score and serological and parasitological test results. Based on data from diagnostic tests and clinical scores, the time course of infection was defined as transient asymptomatic infection (11 dogs), persistent asymptomatic infection (2 dogs), and symptomatic infection (8 dogs). Two dogs were lost after the first sand fly season. The results of the present study provide a framework for assessing the clinical status of L. infantum infection in dogs and suggest that infected animals should be monitored over time to expedite therapeutic decisions and plan appropriate control interventions.

Failure of imidocarb dipropionate to eliminate Hepatozoon canis in naturally infected dogs based on parasitological and molecular evaluation methods.

The efficacy of imidocarb dipropionate for the treatment of Hepatozoon canis infection was studied in three naturally infected asymptomatic dogs followed longitudinally over 8 months. Response to treatment was followed by monitoring blood counts, parasitemia levels in blood, parasite in concentrated buffy-coat smears and by PCR. The dogs were initially treated with a low dose of 3 mg/kg imidocarb dipropionate twice a month and when parasitemia persisted after five treatments, with the regular dose of 6 mg/kg. In one dog, H. canis gamonts were no longer detectable by blood and buffy-coat microscopy after 2 months of therapy with 6 mg/kg while in the two other dogs gamonts were intermittently found in blood but persistently detectable in buffy-coat smears during the whole study period. Furthermore, combined therapy with doxycycline monohydrate administered at 10 mg/kg/day PO for 4 weeks also failed to eliminate H. canis. PCR revealed that parasite DNA was present in the blood of all dogs at all sampling dates regardless of treatment refuting the effectiveness of treatment suggested by negative blood microscopy. Detection of H. canis in buffy coat was found to be twice as sensitive than by blood smear and detection by PCR was even more sensitive revealing infection in eight samples (16% of total samples) negative by blood and buffy-coat microscopy. In conclusion, imidocarb dipropionate was not effective in eliminating H. canis from dogs treated repeatedly over 8 months. Microscopical detection is not sufficient for the evaluation of treatment response in H. canis infection and follow up by molecular techniques is recommended.

Acute-Phase Proteins in Dogs Naturally Infected with Leishmania infantum During and After Long-term Therapy with Allopurinol

Sasanelli, M., Paradies, P., de Caprariis, D., Greco, B., De Palo, P., Palmisano, D. and Carelli, G., 2007. Acute-phase proteins in dogs naturally infected with Leishmaniainfantum during and after long-term therapy with allopurinol. Veterinary Research Communications, 31(Suppl. 1), 335–338