RESUMO
BACKGROUND: The increase in reports of resistance to macrocyclic lactones in the canine heartworm, Dirofilaria immitis is alarming. While DNA based tests have been well-validated, they can be expensive. In a previous study, we showed that two biochemical tests adapted to a 96- well plate format and read in a spectrophotometer could detect differences among lab validated D. immitis isolates. The two tests- Resazurin reduction and Hoechst 33342 efflux-detect metabolism and P-glycoprotein activity respectively in microfilariae isolated from infected dog blood. METHODS: Our objective was to optimize the two assays further by testing various assay parameters in D. immitis isolates not tested previously. We tested microfilarial seeding density, incubation time and the effect of in vitro treatment with ivermectin and doxycycline in five other D. immitis isolates-JYD-34, Big Head, Berkeley, Georgia III and LOL. All assays were performed in 3 technical replicates and 2-4 biological replicates. To understand the molecular basis of the assays, we also performed qPCR for selected drug metabolism and elimination associated genes of the ABC transporter and cytochrome P450 gene families. RESULTS: Metabolism and ABC transporter activity as detected by these assays varied between strains. Anthelmintic status (resistant or susceptible) did not correlate with metabolism or P-gp efflux. Basal transcriptional variations were found between strains in ABC transporter and cytochrome P450 genes. CONCLUSIONS: These assays provide a greater understanding of the biochemical variation among isolates of D. immitis, which can be exploited in the future to develop in vitro diagnostic tests capable of differentiating susceptible and resistant isolates.
Assuntos
Dirofilaria immitis , Dirofilariose , Microfilárias , Animais , Dirofilaria immitis/genética , Dirofilaria immitis/metabolismo , Cães , Microfilárias/genética , Dirofilariose/parasitologia , Dirofilariose/sangue , Dirofilariose/diagnóstico , Doenças do Cão/parasitologia , Doenças do Cão/sangue , Ivermectina/farmacologia , Doxiciclina/farmacologia , Resistência a Medicamentos/genética , Membro 1 da Subfamília B de Cassetes de Ligação de ATP/metabolismo , Membro 1 da Subfamília B de Cassetes de Ligação de ATP/genéticaRESUMO
The aim of this study was to determine the concentration of TNF-alpha (TNF-α) in dogs naturally infected with Dirofilaria immitis (D. immitis) and to assess whether there are any changes in TNF-α concentration and their dependence during therapy for heartworm disease (HWD). For this study, 14 client-owned dogs with HWD were selected. Clinical and parasitological examinations (modified Knott test for circulating microfilariae and SNAP Test IDEXX for circulating D. immitis antigen) had been used for diagnosing D. immitis and HWD. All dogs were treated with an alternative therapy for HWD (oral doxycycline 10 mg/kg b.w., once daily for 6 weeks, then alternately 4 weeks without and 2 weeks with the medication, and oral ivermectin 6-14 µg/kg b.w., every 2 weeks). The dogs blood sera at the moment of HWD diagnosis, during and at the end of therapy were frozen for further quantifying of TNF-α (Canine TNF-alpha ELISA kit, Thermo scientific). At the moment of HWD diagnosis TNF-α was detected in 9 dogs (7.21±12.44 pg/ml). Concentration of TNF-α was not significantly change during the therapy, neither related to the level of D. immitis antigen nor to antigen level changes. The alternative therapy for HWD has no influence on TNF-α concentration dynamics.
Assuntos
Dirofilaria immitis , Dirofilariose , Doenças do Cão , Fator de Necrose Tumoral alfa , Animais , Cães , Dirofilariose/diagnóstico , Dirofilariose/tratamento farmacológico , Dirofilariose/sangue , Doenças do Cão/tratamento farmacológico , Doenças do Cão/diagnóstico , Doenças do Cão/sangue , Fator de Necrose Tumoral alfa/sangue , Masculino , Feminino , Doxiciclina/uso terapêutico , Ivermectina/uso terapêuticoRESUMO
BACKGROUND: Enhanced platelet responses have been demonstrated in heartworm-infected (HWI) dogs; however, the cause and clinical implications of altered platelet function have not been fully elucidated. OBJECTIVE: This study evaluated platelet function in HWI dogs. METHODS: Anticoagulated whole blood collected from eight HWI and eight uninfected dogs was evaluated using turbidometric platelet aggregometry, a platelet function analyzer (PFA-100), a total thrombus analysis system (T-TAS), tissue factor-activated and tissue plasminogen activator modified thromboelastography (TF- and tPA-TEG), CBC, von Willebrand Factor activity, and fibrinogen concentrations. Platelet activation state and the presence of reticulated platelets were assessed via flow cytometric expression of P-selection (CD-62P) and thiazole orange staining. RESULTS: Platelet aggregation responses to adenosine diphosphate (ADP, 10 µM) or collagen (20 µg/mL), PFA-100 closure times, and T-TAS occlusion times did not differ between groups. TEG values TF-R, tPA-R, TF-K, and TF-LY60 were decreased (P = .025, P = .047, P = .038, P = .025) and TF-MA, tPA-MA, TF-G, tPA-G and TF-alpha angle were increased (P < .04) in HWI dogs. HWI dogs had higher fibrinogen concentrations (465.6 ± 161 mg/dL vs 284.5 ± 38 mg/dL, P = .008) and eosinophil counts (0.686 ± 0.27 × 103/µL vs 0.267 ± 0.20 × 103/µL, P = .003). There was no difference in hematocrit, activation state, or percent of reticulated platelets. Non-activated reticulated platelets exhibited higher CD62P expression compared with mature platelets. CONCLUSIONS: Chronic canine heartworm disease was accompanied by hypercoagulability, hyperfibrinogenemia, and decreased fibrinolysis. Enhanced platelet activation was not identified in this group of HWI dogs.
Assuntos
Coagulação Sanguínea , Dirofilariose , Doenças do Cão , Ativação Plaquetária , Animais , Cães , Doenças do Cão/sangue , Doenças do Cão/parasitologia , Dirofilariose/sangue , Feminino , Masculino , Testes de Função Plaquetária/veterinária , Plaquetas , Agregação Plaquetária , Citometria de Fluxo/veterinária , Tromboelastografia/veterinária , Dirofilaria immitisRESUMO
BACKGROUND: Canine heartworm (Dirofilaria immitis) is a life-threatening infection of dogs with a global distribution. Information on the prevalence of D. immitis and associated risk factors for canine heartworm antigen positivity-and thus disease-in Australia is scarce or outdated. The current reference method for D. immitis diagnosis in dogs is via the detection of heartworm antigen in blood using commercially available microwell-based enzyme-linked immunosorbent assays (ELISAs). Heat treatment of canine plasma prior to testing has been suggested to increase test sensitivity. The aim of the current study was to estimate the prevalence of D. immitis in dogs confined to shelters in Queensland, Australia. The impact of heat treatment on antigen test results was also assessed. METHODS: Blood samples (n = 166) were collected directly from dogs in seven shelters across Queensland (latitudinal span of approx. 1700 km) into EDTA blood collection tubes. A commercially available ELISA (DiroCHEK®) was used to detect canine heartworm antigen in untreated and heat-treated plasma. Whole blood was concurrently tested for the presence of microfilariae and D. immitis DNA using a modified Knott's test and real-time PCR, respectively. Risk factors (age, gender, source, location) associated with the odds of positivity for canine heartworm were assessed using binary logistic regression models. RESULTS: A total of 16 dogs (9.6%; 95% confidence interval [CI]: 5.9-15.2%) were positive for canine heartworm based on combined test results. Heat treatment did not impact on the positivity of D. immitis antigen within samples (Cohen's kappa = 0.98), but the optical density was significantly increased in paired plasma samples for D. immitis antigen-positive samples (Wilcoxon matched-pairs signed rank test, two-tailed P < 0.01). Location of the dog in a shelter in northern Queensland was the only risk factor significantly associated with the odds of a dog being more likely to be D. immitis antigen positive (odds ratio: 4.39; 95% CI: 1.26-13.51). All samples positive for the modified Knott's test were also positive for D. immitis DNA by PCR. CONCLUSIONS: This study demonstrated the presence of heartworm-positive dogs in shelters in Queensland, with positive animals significantly more likely to occur in northern Queensland than southern Queensland. Sustained testing for the presence of D. immitis microfilariae and antigen remain important diagnostic tools in areas with known and re-emerging canine heartworm activity.
Assuntos
Antígenos de Helmintos/sangue , Dirofilaria/química , Dirofilariose/diagnóstico , Dirofilariose/epidemiologia , Doenças do Cão/diagnóstico , Doenças do Cão/epidemiologia , Animais , Dirofilaria/imunologia , Dirofilariose/sangue , Doenças do Cão/sangue , Cães , Ensaio de Imunoadsorção Enzimática/métodos , Feminino , Masculino , Prevalência , Queensland/epidemiologia , Fatores de RiscoRESUMO
As part of the national recovery effort, endangered black-footed ferrets (Mustela nigripes) were reintroduced to the Cheyenne River Sioux Reservation in South Dakota, US in 2000. Despite an encouraging start, numbers of ferrets at the site have declined. In an effort to determine possible causes of the population decline, we undertook a pathogen survey in 2012 to detect exposure to West Nile virus (WNV), canine distemper virus (CDV), plague (Yersinia pestis), tularemia (Francisella tularensis), and heartworm (Dirofilaria immitis) using coyotes (Canis latrans) as a sentinel animal. The highest seroprevalence was for WNV with 71% (20/28) of coyotes testing antibody-positive. Seroprevalence of CDV and plague were lower, 27% and 13%, respectively. No evidence of active infection with tularemia or heartworm was seen in the coyotes sampled. As this study did not sample black-footed ferrets themselves, the definitive cause for the decline of this population cannot be determined. However, the presence of coyotes seropositive for two diseases, plague and CDV, lethal to black-footed ferrets, indicated the potential for exposure and infection. The high seroprevalence of WNV in the coyotes indicated a wide exposure to the virus; therefore, exposure of black-footed ferrets to the virus is also likely. Due to the ability of WNV to cause fatal disease in other species, studies may be useful to elucidate the impact that WNV could have on the success of reintroduced black-footed ferrets as well as factors influencing the spread and incidence of the disease in a prairie ecosystem.
Assuntos
Doenças dos Animais/epidemiologia , Coiotes/sangue , Dirofilariose/epidemiologia , Cinomose/epidemiologia , Furões , Peste/veterinária , Animais , Anticorpos Antibacterianos/sangue , Anticorpos Anti-Helmínticos/sangue , Anticorpos Antivirais/sangue , Dirofilaria immitis , Dirofilariose/sangue , Cinomose/sangue , Cinomose/virologia , Vírus da Cinomose Canina , Feminino , Masculino , Peste/epidemiologia , Densidade Demográfica , Estudos Soroepidemiológicos , South Dakota/epidemiologia , Febre do Nilo Ocidental/sangue , Febre do Nilo Ocidental/epidemiologia , Febre do Nilo Ocidental/veterinária , Febre do Nilo Ocidental/virologia , Yersinia pestisRESUMO
Dirofilaria immitis causes life-threatening heart disease in dogs, thus screening of dog populations is important. Lens-free technology (LFT) is a low-cost imaging technique based on light diffraction that allows computerized recognition of small objects in holographic images. We evaluated an algorithm capable of recognizing microfilariae in canine whole blood using the LFT. We examined 3 groups of 10 EDTA blood specimens, from dogs with microfilaremia (group A), healthy dogs (B), and dogs with hematologic modifications other than microfilaremia (C). The LFT analyzer photographed repeated series of 5 images of all samples. The algorithm declared a sample positive if a microfilaria was detected on ≥1, ≥2, or ≥3 of the 5 images of a series. Microfilariae were detected visually in the images in 9 of 10 cases in group A; no microfilariae were seen in the images from groups B and C. Of the 30 cases, there were 14, 4, and only 3 false-positives with the 1 of 5, 2 of 5, and 3 of 5 image cutoffs, respectively. There were no false-negatives, regardless of cutoff. LFT seems useful for detecting microfilaria and could have application in clinical pathology.
Assuntos
Dirofilaria immitis/isolamento & purificação , Dirofilariose/diagnóstico , Doenças do Cão/diagnóstico , Ácido Edético/sangue , Medicina Veterinária/instrumentação , Animais , Dirofilariose/sangue , Doenças do Cão/sangue , Cães , Feminino , Masculino , Microfilárias/isolamento & purificaçãoRESUMO
BACKGROUND: Detection of Dirofilaria immitis, or heartworm, through antigen in sera is the primary means of diagnosing infections in dogs. In recent years, the practice of heat-treating serum prior to antigen testing has demonstrated improved detection of heartworm infection. While the practice of heat-treating serum has resulted in earlier detection and improved sensitivity for heartworm infections, it has been suggested that heat treatment may cause cross reactivity with A. reconditum and intestinal helminth infections of dogs. No studies have assessed the potential cross-reactivity of these parasites with heartworm tests before and after heat treatment using blood products and an appropriate gold standard reference. METHODS: Canine sera (n=163) was used to evaluate a heartworm antigen-ELISA (DiroCHEK®) and potential cross-reactivity with common parasitic infections. The heartworm status and additional parasite infections were confirmed by necropsy and adult helminth species verified morphologically or by PCR, and feces evaluated by centrifugal fecal flotation. RESULTS: Intestinal parasites were confirmed in 140 of the dogs by necropsy, and 130 by fecal flotation. Acanthocheilonema reconditum microfilariae were confirmed in 22 dogs. Prevalence of heartworm infection confirmed by necropsy was 35.6% (58/163). In the 105 dogs without heartworms, specificity remained unchanged at 100% both before and after heat treatment despite confirmed infections with A. reconditum, Ancylostoma caninum, Ancylostoma brasiliense, Trichuris vulpis, Toxocara canis, Dipylidium caninum, Spirometra mansonoides, Macracanthorynchus ingens, Cystoisospora sp., Giardia sp., and Sarcocystis sp. CONCLUSIONS: These findings suggest that the use of heat treatment improves sensitivity of heartworm tests and is unlikely to cause false positive antigen results due to Acanthocheilonema reconditum, intestinal helminths, and protozoal parasites in dogs.
Assuntos
Antígenos de Helmintos/sangue , Antígenos de Protozoários/sangue , Dirofilaria immitis/química , Dirofilariose/diagnóstico , Temperatura Alta , Soro/parasitologia , Animais , Reações Cruzadas , Dirofilaria immitis/classificação , Dirofilaria immitis/isolamento & purificação , Dirofilariose/sangue , Cães , Ensaio de Imunoadsorção Enzimática/métodos , Feminino , MasculinoRESUMO
Recent studies have found that anemia and anisocytosis are precipitating factors for certain heart diseases in dogs. This study evaluated the prevalence and correlation of anemia and red blood cell distribution width (RDW) in dogs with heartworm disease (HWD). The study population consisted of 20 healthy control dogs and 86 dogs with HWD: 28 dogs with no clinical signs or pulmonary hypertension (Group 1), 42 dogs with mild clinical signs but no pulmonary hypertension (Group 2), and 16 dogs with severe clinical signs and pulmonary hypertension (Group 3). Along with echocardiographic interrogation of pulmonary hypertension, red blood cell (RBC) profiles were evaluated, including RDW. The total number of red blood cells (tRBCs), hematocrit (HCT), and hemoglobin (HGB) concentration was significantly lower in Group 3 dogs compared to control dogs (P < 0.05), while the RDW was significantly higher in Group 3 dogs than in control dogs (P < 0.05). The RDW was closely correlated to other RBC profiles and the presence of pulmonary hypertension (P < 0.05). The severity of tricuspid regurgitant gradient (TRG) was closely correlated with Hb and tRBC (P < 0.05), but not with the RDW and reticulocyte count. This study finding indicated that anemia and anisocytosis are common complications in dogs with severe clinical signs and pulmonary hypertension caused by heartworm disease (HWD). It would therefore be beneficial for clinicians to routinely check red blood cell (RBC) profiles, including RDW, in order to monitor the progression of heartworm disease in dogs.
Des études récentes ont montré que l'anémie et l'anisocytose sont des facteurs précipitants pour certaines conditions cardiaques chez les chiens. La présente étude a évalué la prévalence et la corrélation de l'anémie et de la distribution de la largeur des globules rouges (RDW) chez des chiens avec la maladie des vers du coeur (HWD). La population à l'étude consistait en 20 chiens témoins en santé et de 86 chiens avec HWD : 28 chiens sans signe clinique ou hypertension pulmonaire (Groupe 1), 42 chiens avec signes cliniques légers mais sans hypertension pulmonaire (Groupe 2) et 16 chiens avec signes cliniques sévères et hypertension pulmonaire (Groupe 3). En plus de l'interrogation échocardiographique de l'hypertension pulmonaire, les profils des globules rouges (RBC) furent évalués, incluant la RWD. Le nombre total de globules rouges (tRBCs), l'hématocrite (HCT) et la concentration en hémoglobine (Hb) étaient significativement plus bas chez les chiens du groupe 3 comparativement aux chiens témoins (P < 0,05) alors que la RWD était significativement plus élevée chez les chiens du Groupe 3 que chez les chiens témoins (P < 0,05). La RWD était étroitement corrélée à d'autres profiles de RBC et à la présence d'hypertension pulmonaire (P < 0,05). La sévérité du gradient de régurgitation de la tricuspide (TRG) était étroitement corrélée avec Hb et tRBC (P < 0,05), mais pas avec RWD et le dénombrement de réticulocytes. Les trouvailles de cette étude indiquent que l'anémie et l'anisocytose sont des complications fréquentes chez les chiens avec des signes cliniques sévères et de l'hypertension pulmonaire causés par HWD. Il serait donc bénéfique pour les cliniciens de vérifier de routine les profiles de RBC, incluant RWD, afin de suivre la progression de la maladie des vers du coeur chez les chiens.(Traduit par Docteur Serge Messier).
Assuntos
Dirofilariose/sangue , Doenças do Cão/sangue , Eritrócitos/fisiologia , Animais , Cães , Feminino , MasculinoRESUMO
BACKGROUND: Dirofilaria immitis is responsible for heartworm disease in dogs in endemic areas worldwide. Screening for this infection is done by blood tests. Antigen testing is the most sensitive method to detect an infection with adult (female) worms. Microscopic examination of a blood smear or Knott's test can be used to detect circulating microfilariae, the infective larvae. To increase the sensitivity of the antigen test by decreasing the false negative test results, heating of the blood sample has been recommended in recent guidelines. Heating is believed to remove blocking immune-complexes. Circulating microfilariae are not specific findings for heartworm infection, as other nematodes (among others, Acanthocheilonema dracunculoides) can also result in microfilaremia. Although the type of microfilariae cannot be determined by microscopy alone, real-time PCR can reliably identify the infecting nematode species. Correct identification of the parasite is of major importance, as an infection with D. immitis requires antiparasitic therapy, whereas A. dracunculoides is thought to be a clinically irrelevant coincidental finding. The present case report describes a microfilaremic dog where the initial antigen test for D. immitis turned positive after heat treatment, whereas real-time PCR revealed that the microfilariae were A. dracunculoides (syn. Dipetalonema dracunculoides). RESULTS: A circa 5-year old, asymptomatic Spanish mastiff dog was referred for heartworm therapy because microfilariae were found via a screening blood test. The dog was recently imported to the Netherlands from Spain, where it had been a stray dog. Antigen tests on a plasma sample for D. immitis were performed with three different test kits, which all turned out to be negative. However, heat treatment of two of these samples were carried out and both of them led to a positive antigen test result. Real-time PCR showed that the circulating microfilariae belonged to A. dracunculoides species. Three administrations of moxidectin spot-on at monthly intervals resulted in a negative antigen and a negative Knott's tests one month after the last treatment. CONCLUSIONS: We conclude that heat treatment of initially negative blood samples for D. immitis could lead to false positive antigen test results if the dog is infected with A. dracunculoides.
Assuntos
Acanthocheilonema/isolamento & purificação , Acantoqueilonemíase/veterinária , Antígenos de Helmintos/sangue , Dirofilaria immitis/isolamento & purificação , Dirofilariose/parasitologia , Doenças do Cão/parasitologia , Microfilárias/isolamento & purificação , Acanthocheilonema/genética , Acanthocheilonema/imunologia , Acantoqueilonemíase/sangue , Acantoqueilonemíase/parasitologia , Animais , Sangue/parasitologia , Dirofilaria immitis/genética , Dirofilaria immitis/imunologia , Dirofilariose/sangue , Dirofilariose/diagnóstico , Doenças do Cão/sangue , Doenças do Cão/diagnóstico , Cães , Reações Falso-Positivas , Feminino , Temperatura Alta , Testes Imunológicos , Microfilárias/genética , Microfilárias/imunologiaRESUMO
The species of the genus Dirofilaria are filarial parasites causing zoonotic infections in humans with an increasing incidence in temperate and tropical areas of the world. Due to its classification as a vector-borne disease, the most important factors influencing dirofilariosis transmission are those related to climate, such as temperature and humidity. However, other factors linked with human behaviour can influence the distribution of the parasite. Although the Russian Federation could be considered as a non-suitable area for Dirofilaria spp. transmission due to its climatic conditions, one third of the human cases of dirofilariosis have been declared in this country. Here, seroepidemiological data on human dirofilariosis for five different regions distributed throughout the Russian Federation (Rostov, Moscow, Ekaterinburg, Yakutia and Khabarovsk) were obtained. A total of 940 serum samples from totally random donors living in these areas were analysed by enzyme-linked immunosorbent assay for the detection of anti-Dirofilaria immitis immunoglobulin G antibodies. Similar seroprevalence data ranging from 3.41% in Yakutia to 6.95% in Khabarovsk, with no significant correlation with climatic data of yearly average temperature and rainfall from these regions were found. These results suggest that other factors probably related to human behaviour, and not only climatic conditions, might be facilitating the spread of human dirofilariosis in these areas.
Assuntos
Comportamento , Clima , Dirofilariose/sangue , Dirofilariose/transmissão , Zoonoses/transmissão , Adulto , Animais , Anticorpos Anti-Helmínticos/sangue , Dirofilaria immitis/imunologia , Dirofilariose/epidemiologia , Feminino , Geografia , Humanos , Imunoglobulina G/sangue , Masculino , Pessoa de Meia-Idade , Federação Russa/epidemiologia , Estudos Soroepidemiológicos , Temperatura , Zoonoses/epidemiologia , Zoonoses/parasitologiaRESUMO
Canine vector-borne pathogens are a group of widespread microorganisms and nematodes transmitted by arthropods that do not only impact dog health but may also pose a health risk to humans as many of them are zoonotic. As no data exist on the presence of canine vector-borne pathogens in Kosovo, we here present a first study on the seroprevalence of selected vector-borne pathogens, the dog heartworm Dirofilaria immitis and the bacteria Anaplasma spp., Ehrlichia spp. and Borrelia burgdorferi sensu lato. The study was carried out from July to October 2019 in all regions of Kosovo and included 149 clinically healthy dogs (84 owned, 40 sheltered and 25 free-ranging). Blood samples collected from each individual were tested using a commercially available rapid multiplex enzyme-linked immunosorbent assay. In total, 37.6% of the examined dogs were seropositive for one or more of the target pathogens. Most frequently, antibodies were found against Anaplasma spp. (24.8% of the dogs tested), followed by antigen detection of D. immitis (14.8%) and antibodies of B. burgdorferi s.l. (1.3%). The lowest antibody prevalence (0.7%) showed E. canis where only one dog was found positive. This preliminary study demonstrates the circulation of several zoonotic vector-borne pathogens in natural cycles involving dogs in Kosovo. It should trigger studies on infection prevalences in humans and initiate vector surveillance programmes in order to manage and control transmission and the diseases associated with the pathogens.
Assuntos
Anaplasmose/epidemiologia , Dirofilariose/epidemiologia , Doenças do Cão/epidemiologia , Ehrlichiose/veterinária , Doença de Lyme/veterinária , Anaplasma , Anaplasmose/sangue , Animais , Anticorpos/sangue , Borrelia burgdorferi , Dirofilaria immitis/imunologia , Dirofilariose/sangue , Vetores de Doenças , Doenças do Cão/sangue , Cães , Ehrlichia , Ehrlichiose/epidemiologia , Ensaio de Imunoadsorção Enzimática , Kosovo/epidemiologia , Doença de Lyme/sangue , Doença de Lyme/epidemiologia , Masculino , Estudos SoroepidemiológicosRESUMO
Cats are less susceptible to Dirofilaria immitis infection than dogs. Although rare, the feline disease can be fatal even with low parasitic loads. The infection is often asymptomatic or has non-specific symptoms that are mainly associated with the death of immature worms. Microfilaremia is rare and transient. Normally, microfilaremia, when present, lasts for not more than 33 days. This study describes a feline case presenting with non-specific clinical signs and prolonged microfilaremia. Case: a random bred cat infected by feline leukemia virus (FeLV) that was found to be microfilaremic by chance. The infection was detected by the presence of microfilariae in a blood smear and was confirmed by antigen test (SNAP Feline Triple Test, Idexx®) and echocardiogram.
Assuntos
Doenças do Gato , Dirofilaria immitis , Dirofilariose , Infecções por Retroviridae , Animais , Doenças do Gato/parasitologia , Doenças do Gato/virologia , Gatos , Dirofilariose/sangue , Dirofilariose/complicações , Dirofilariose/diagnóstico , Dirofilariose/parasitologia , Vírus da Leucemia Felina , Infecções por Retroviridae/complicações , Infecções por Retroviridae/veterináriaRESUMO
BACKGROUND: The Cumberland Gap Region (CGR) of the United States is a natural corridor between the southeastern, northeastern, and midwestern regions of the country. CGR has also many species of ticks and mosquitos that serve as competent vectors for important animal and human pathogens. In this study, we tested dogs from six different animal shelters in the CGR for Rocky Mountain spotted fever (RMSF), anaplasmosis, Lyme disease, canine ehrlichiosis and canine heartworm disease. RESULTS: Sera from 157 shelter dogs were tested for antibodies to RMSF agent, Rickettsia rickettsii, using an indirect immunofluorescence assay. Sixty-six dogs (42.0%) were positive for either IgM or IgG, or both IgM and IgG antibodies to R. rickettsii. Moreover, the same set of sera (n = 157) plus an and additional sera (n = 75) from resident dogs at the same shelters were tested using the SNAP 4Dx Plus. Of 232 dogs tested, two (0.9%) were positive for antibodies to Anaplasma phagocytophilum/A. platys, nine (3.9%) were positive for antibodies to Borrelia burgdorferi, 23 (9.9%) for positive for antibodies to Ehrlichia canis/E. ewingii, and 13 (5.6%) were positive for Dirofilaria immitis antigen. Co-infection with two or more etiologic agents was detected in five animals. Three dogs had antibodies to both B. burgdorferi and E. canis/E. ewingii, and two dogs were positive for D. immitis antigen and antibodies to B. burgdorferi and E. canis/E. ewingii. CONCLUSIONS: Shelter dogs in the CGR are exposed to a number of important vector-borne pathogens. Further studies are required to ascertain the roles these animals play in maintenance and transmission of these pathogens.
Assuntos
Coinfecção/veterinária , Doenças do Cão/microbiologia , Doenças do Cão/parasitologia , Doenças Transmitidas por Vetores/veterinária , Anaplasma/imunologia , Anaplasma/isolamento & purificação , Anaplasmose/sangue , Animais , Anticorpos Antibacterianos/sangue , Antígenos de Helmintos/sangue , Região dos Apalaches/epidemiologia , Borrelia burgdorferi/imunologia , Borrelia burgdorferi/isolamento & purificação , Coinfecção/epidemiologia , Dirofilaria immitis/imunologia , Dirofilaria immitis/isolamento & purificação , Dirofilariose/sangue , Doenças do Cão/epidemiologia , Cães , Ehrlichia/imunologia , Ehrlichia/isolamento & purificação , Ehrlichiose/sangue , Ehrlichiose/veterinária , Feminino , Doença de Lyme/sangue , Doença de Lyme/veterinária , Masculino , Rickettsia rickettsii/imunologia , Rickettsia rickettsii/isolamento & purificação , Febre Maculosa das Montanhas Rochosas/sangue , Febre Maculosa das Montanhas Rochosas/veterinária , Estudos Soroepidemiológicos , Doenças Transmitidas por Vetores/sangueRESUMO
BACKGROUND: Dirofilaria immitis, Leishmania infantum and Toxoplasma gondii are zoonotic parasites which can affect domestic cats. Considering the lack of published data from the local feline population, this study aimed to assess infection with or exposure to these pathogens in cats from Madeira Island, Portugal. METHODS: One hundred and forty-one domestic cats (77 males and 64 females; median age: 2 years) were sampled at a veterinary medical centre in Funchal, from September 2018 to January 2019. Serum samples were tested for D. immitis antigen, with an enzyme-linked immunosorbent assay kit, and for antibodies to Leishmania spp. or to T. gondii, with the direct agglutination test and the modified agglutination test, respectively. RESULTS: Five cats (3.5%; 95% confidence interval, CI: 1.2-8.1) were positive to D. immitis; no cats were seropositive to Leishmania spp. (0%; 95% CI: 0-2.6%); and 43 cats (30.5%; 95% CI: 23.0-38.8%) were seropositive to T. gondii. Prevalence of the D. immitis antigen was significantly different between cats that received ectoparasiticides and those which did not (0 vs 12.2%; P = 0.009). Prevalence of antibodies to T. gondii was significantly different between juvenile and adult cats (12.8 vs 38.0%; P = 0.007). There were two cats concurrently positive to D. immitis and T. gondii, but no statistical association between these two dependent variables was found (P = 0.641). CONCLUSIONS: To our knowledge, this is the first report of the presence of parasites D. immitis and T. gondii in the feline population of Madeira Island. Knowledge on the epidemiological situation of these and other zoonotic pathogens should raise awareness, both at the veterinary medical and public health levels, and contribute to promoting prevention and control.
Assuntos
Anticorpos Antiprotozoários/sangue , Antígenos de Helmintos/sangue , Doenças do Gato/parasitologia , Dirofilariose/imunologia , Toxoplasmose Animal/imunologia , Animais , Doenças do Gato/sangue , Doenças do Gato/imunologia , Gatos/imunologia , Dirofilaria immitis/imunologia , Dirofilariose/sangue , Dirofilariose/epidemiologia , Feminino , Leishmania infantum/imunologia , Masculino , Animais de Estimação/microbiologia , Portugal/epidemiologia , Prevalência , Estudos Soroepidemiológicos , Toxoplasma/imunologia , Toxoplasmose Animal/sangue , Toxoplasmose Animal/epidemiologiaRESUMO
BACKGROUND: Detection of D. immitis microfilaria (mf) is an important diagnostic skill in veterinary medicine and is critical to Day 1 veterinarians and technicians. Finding a supply of blood containing mf to teach the technique and formalin's adverse environmental effects used in the diagnostic microscopic tests present a challenge. RESULTS: This study evaluated the use of cryopreserved and recently drawn mf-infected blood along with two fixative reagents, acetic acid or formalin for mf detection. The specific aims included determining if veterinary students could 1) detect cryopreserved mf added to fresh blood using routine diagnostic testing and 2) detect morphological differences in the mf. The 236 students were kept blind from the sample status. The ability of the students to identify mf and the mf morphology were compared for the samples and fixatives evaluated. The results demonstrate using a combination of cryopreservation and acetic acid for teaching microfilaria diagnostic techniques is fleasible; however, the quality of the mf morphology is less than optimal when compared to freshly acquired mf containing blood. Compared to reference values, the mf demonstrated a decrease in size with each additional variable evaluated. CONCLUSION: A majority (98.3%) of the 236 students correctly identified the presence of mf. Teaching laboratories could utilize cryopreserved mf-spiked donor blood in lieu of freshly collected mf-containing blood from a naturally or experimentally infected dog. Substitution of less hazardous chemicals for the fixative can be used. Finally, the change in size measurements provides a mechanism to ensure students can correctly measure mf as students are required to do verifiable measurements and cannot copy reference values from a text book since the cryopreservation and fixation methods cause the mf to measure smaller than textbook reference values.
Assuntos
Dirofilaria immitis , Dirofilariose/diagnóstico , Doenças do Cão/diagnóstico , Microfilárias , Ácido Acético , Animais , Criopreservação/métodos , Criopreservação/veterinária , Dirofilariose/sangue , Doenças do Cão/sangue , Doenças do Cão/parasitologia , Cães , Educação em Veterinária/métodos , Estudos de Viabilidade , Fixadores , Formaldeído , Humanos , EstudantesRESUMO
Abstract Cats are less susceptible to Dirofilaria immitis infection than dogs. Although rare, the feline disease can be fatal even with low parasitic loads. The infection is often asymptomatic or has non-specific symptoms that are mainly associated with the death of immature worms. Microfilaremia is rare and transient. Normally, microfilaremia, when present, lasts for not more than 33 days. This study describes a feline case presenting with non-specific clinical signs and prolonged microfilaremia. Case: a random bred cat infected by feline leukemia virus (FeLV) that was found to be microfilaremic by chance. The infection was detected by the presence of microfilariae in a blood smear and was confirmed by antigen test (SNAP Feline Triple Test, Idexx®) and echocardiogram.
Resumo Gatos são menos susceptíveis à infecção por Dirofilaria immitis do que cães. Apesar de rara, a doença nos gatos pode ser fatal mesmo com baixas cargas parasitárias. Muitas vezes, a doença é assintomática ou apresenta sintomas inespecíficos, principalmente associados com a morte de formas parasitárias imaturas. Microfilaremia é rara e transitória. Normalmente, quando ocorre microfilaremia, ela permanece por, no máximo, 33 dias. Este estudo descreve o caso de um felino que apresentava sinais inespecíficos e microfilaremia prolongada: um gato sem raça definida, portador de infecção pelo vírus da leucemia felina (FeLV) que foi diagnosticado como microfilaremico ao acaso. A infecção foi detectada pela presença de microfilárias em esfregaço sanguíneo e, posteriormente, confirmada pelo teste de antígenos (SNAP Feline Triple Test, Idexx®) e por ecocardiograma.
Assuntos
Animais , Gatos , Doenças do Gato/parasitologia , Doenças do Gato/virologia , Dirofilaria immitis , Dirofilariose/complicações , Dirofilariose/diagnóstico , Dirofilariose/sangue , Vírus da Leucemia Felina , Infecções por Retroviridae/complicações , Infecções por Retroviridae/veterinária , Dirofilariose/parasitologiaRESUMO
A 75-year-old man presented with a 1-cm large elastic soft subcutaneous nodule on the left side of the umbilicus, which when excised showed presence of a helminthic form within the granulomatous lesions. Morphologically, the helminth was considered to be of the genus Dirofilaria, and the patient showed increased serum antibody titer against canine filaria. The partial DNA sequence of the mitochondrial 12S rRNA gene locus of this clinical isolate showed the highest nucleotide identity (89.6%) with Dirofilaria repens; however, the phylogenetic analysis addressed the haplotype and Dirofilaria ursi as outgroups of the clusters of D. repens and Dirofilaria immitis, which are the causal agents of most human dirofilariasis. As like bear filaria D. ursi, a wide variety of other carnivore-parasitizing filaria species have rarely been reported in humans. The newly detected genetic haplotype in this case may correspond to one of these species of Dirofilaria, though the genetic references are not available thus far.
Assuntos
DNA de Helmintos/genética , Dirofilaria/genética , Dirofilariose/parasitologia , Tela Subcutânea/parasitologia , Idoso , Animais , Anticorpos Anti-Helmínticos/sangue , Anticorpos Anti-Helmínticos/imunologia , DNA de Helmintos/isolamento & purificação , DNA Mitocondrial/genética , DNA Mitocondrial/isolamento & purificação , Dirofilaria/imunologia , Dirofilaria/isolamento & purificação , Dirofilariose/sangue , Dirofilariose/diagnóstico , Técnicas de Genotipagem , Haplótipos , Humanos , Masculino , Filogenia , RNA Ribossômico/genética , Tela Subcutânea/patologia , UmbigoRESUMO
Canine vector-borne pathogens (VBPs) are a group of globally distributed and rapidly spreading microorganisms transmitted by arthropods. In the present survey, we investigated Anaplasma spp., Ehrlichia canis, Dirofilaria immitis and Borrelia burgdorferi sensu lato seroprevalence between three groups of dogs (asymptomatic, suspected and deceased) from continental and coastal regions of Croatia with the commercial point-of-care SNAP®4Dx®Plus for VBPs. The overall prevalence for tested pathogens in dogs was 6.1% with the highest prevalence detected for Anaplasma spp. (4.5%), while the remaining pathogens were found at a prevalence of less than 1% (E. canis 0.6%, B. burgdorferi s.l. 0.4%, D. immitis 0.6%). No statistically significant differences in VBP detection between dog cohorts could be found with the exception of D. immitis in the deceased group. Interestingly, no evidence of D. immitis could be found in the hearts of dogs in this group at necropsy, however. This study provides the first data on the seroprevalence of selected VBPs between dogs of different health statuses in Croatia. The results demonstrate that serological evidence of VBPs alone or in combination with co-infections were found just as frequently in asymptomatic dogs as those with suspected or confirmed evidence of VBP disease, raising questions about the pathogenic potential of these organisms in domesticated dogs.
Assuntos
Doenças do Cão/sangue , Doenças do Cão/epidemiologia , Anaplasma/imunologia , Anaplasma/isolamento & purificação , Anaplasmose/sangue , Anaplasmose/epidemiologia , Anaplasmose/microbiologia , Animais , Borrelia burgdorferi/imunologia , Borrelia burgdorferi/isolamento & purificação , Coinfecção/sangue , Coinfecção/parasitologia , Coinfecção/veterinária , Croácia/epidemiologia , Dirofilaria immitis/imunologia , Dirofilaria immitis/isolamento & purificação , Dirofilariose/sangue , Dirofilariose/epidemiologia , Dirofilariose/parasitologia , Vetores de Doenças , Doenças do Cão/microbiologia , Doenças do Cão/parasitologia , Cães , Ehrlichia canis/imunologia , Ehrlichia canis/isolamento & purificação , Ehrlichiose/sangue , Ehrlichiose/epidemiologia , Ehrlichiose/microbiologia , Ehrlichiose/veterinária , Feminino , Doença de Lyme/sangue , Doença de Lyme/epidemiologia , Doença de Lyme/microbiologia , Doença de Lyme/veterinária , Masculino , Prevalência , Fatores de Risco , Estudos SoroepidemiológicosRESUMO
Dirofilaria immitis and Acanthocheilonema reconditum are common parasites in dogs but have also been reported parasitizing humans. The differential diagnosis and epidemiological evaluation of these zoonoses are important to the development of efficient public health policies and control strategies. The purpose of this study was to carry out an epidemiological survey by using molecular methods for the specific identification of filarid parasites of domestic dogs in the Marajó mesoregion, State of Pará (PA), Brazil. A total of 418 canine blood samples from Marajó mesoregion (Northern Brazil) were collected, submitted to DNA extraction, polymerase chain reaction (PCR) with "pan filarial" primer, subsequent sequencing and sequence analysis using BLASTn software comparison with previously deposited sequences in GenBank. After that, a phylogenetic analysis by Maximum Parsimony was performed to aid the specific diagnosis. The obtained sequences showed the occurrence of 9 (2.15%) dogs infected with D. immitis and 30 (7.18%) by A. reconditum, with a confidence interval of 95%, there were no cases of co-infection. We observed that male dogs were more likely to D. immits and A. reconditum infection. However, age was not significant to both infections. This study reports for the first time the occurrence of A. reconditum in the northern region of Brazil and confirmed the presence of D. immitis in the Marajó mesoregion.
Assuntos
Acantoqueilonemíase/veterinária , Dirofilariose/epidemiologia , Dirofilariose/parasitologia , Doenças do Cão/epidemiologia , Doenças do Cão/parasitologia , Acanthocheilonema , Acantoqueilonemíase/sangue , Acantoqueilonemíase/epidemiologia , Acantoqueilonemíase/parasitologia , Animais , Brasil , Dirofilaria immitis , Dirofilariose/sangue , Doenças do Cão/sangue , Cães , Feminino , Masculino , Epidemiologia Molecular , Doenças Negligenciadas/sangue , Doenças Negligenciadas/epidemiologia , Doenças Negligenciadas/parasitologia , Doenças Negligenciadas/veterinária , Filogenia , Zoonoses/sangue , Zoonoses/epidemiologia , Zoonoses/parasitologiaRESUMO
Prophylaxis with macrocyclic lactone (ML) endectocides is the primary strategy for heartworm control. Recent evidence has confirmed that ML-resistant Dirofilaria immitis isolates have evolved. Comparison of genomes of ML-resistant isolates show they are genetically distinct from wild-type populations. Previously, we identified single nucleotide polymorphisms (SNPs) that are correlated with phenotypic ML resistance. Since reliable in vitro assays are not available to detect ML resistance in L3 or microfilarial stages, the failure to reduce microfilaraemia in infected dogs treated with an ML has been proposed as a surrogate clinical assay for this purpose. The goal of our study was to validate the genotype-phenotype correlation between SNPs associated with ML resistance and failure to reduce microfilaraemia following ML treatment and to identify a minimal number of SNPs that could be used to confirm ML resistance. In this study, 29 participating veterinary clinics received a total of 148 kits containing supplies for blood collection, dosing and prepaid shipping. Patients recruited after a diagnosis of heartworm infection were treated with a single standard dose of Advantage Multi® and a blood sample taken pre- and approximately 2-4 weeks post-treatment. Each sample was processed by performing a modified Knott's Test followed by isolation of microfilariae, genomic DNA extraction and MiSeq sequencing of regions encompassing 10 SNP sites highly correlated with ML resistance. We observed significant correlation of SNP loci frequencies with the ML microfilaricidal response phenotype. Although all predictive SNP combination models performed well, a 2-SNP model was superior to other models tested. The predictive ability of these markers for ML-resistant heartworms should be further evaluated in clinical and epidemiological contexts.