Efficacy of Bravecto® Plus spot-on solution for cats (280 mg/ml fluralaner and 14 mg/ml moxidectin) in the prevention of feline Aelurostrongylus abstrusus infection evaluated in a multi-diagnostic approach.

BACKGROUND: Aelurostrongylus abstrusus is one of the most important respiratory nematodes of felines. Infections may lead to respiratory clinical signs with varying severity or even death, emphasizing the need for preventive treatment of cats with outdoor access to circumvent patent infections. METHODS: Therefore, the preventive efficacy of a spot-on formulation of 280 mg/ml fluralaner and 14 mg/ml moxidectin (Bravecto® Plus spot-on solution for cats, MSD) against A. abstrusus was evaluated in a negative controlled, randomized and partially blinded efficacy study with 28 purpose-bred cats in a non-terminal design. In three different treatment regimes, the minimum recommended dose of 40 mg fluralaner and 2.0 mg moxidectin/kg bodyweight (BW) was administered once at 12, 8 or 4 weeks (study group G1, G2 and G3, respectively) prior to experimental infection with 300 third-stage A. abstrusus larvae, while G4 served as placebo-treated control. RESULTS: From 30 to 46 days post infection (dpi; SD 114 to 130), faeces were sampled to monitor first-stage larvae (L1) excretion for efficacy determination. Secondary efficacy criteria, including respiratory parameters, serological antibody levels and computed tomography (CT) findings, were assessed once before enrolment (SD -7 to -1) and before infection (SD 75 to 83). After infection, CT evaluation was performed once at 47-50 dpi (SD 131 to 134), and respiratory parameters and antibody levels were regularly assessed twice or once a week, respectively (1 up to 78 dpi, SD 85 up to 162). All animals in the control group excreted L1 by 33-37 dpi and remained positive throughout the study period from 41 to 46 dpi (SD 125 to 130). In the treatment groups, only one animal each of G1 and G2 excreted L1 at two consecutive days, and four cats of G1, two of G2 and three of G3 were positive on single occasions. While the geometric mean (GM) of the maximum number of excreted L1 per 5 g of faeces was 7380.89 in the control group (G4), GMs were significantly lower in the treatment groups with 1.63 in G1, 1.37 in G2 and 0.79 in G3. Thus, based on GMs, the reduction in excreted L1 exceeded 99.9% in all three treatment groups. Based on CT severity scores, all lungs of the animals of the control group showed severe pulmonary changes post infection, whereas lungs of the cats of the treatment groups were either unaltered (4 animals), mildly (11 animals), or moderately altered (5 animals). Moreover, seroconversion was observed in all cats of the control group, but not in those of the treatment groups. CONCLUSIONS: The combination of diagnostic methods used in this non-terminal study yielded coherent and reliable results. A single administration of Bravecto® Plus spot-on solution for cats was well tolerated and effective in the prevention of aelurostrongylosis for at least 12 weeks.

Diagnostic criteria and case definitions for abdominal angiostrongyliasis: a systematic review from the Brazilian experience.

Although rare, Angiostrongylus costaricensis infection may be a more prevalent etiology of inflammatory bowel disease than ulcerative colitis and Chron's disease in endemic areas in Central and South America. The present study reviewed the occurrence of A. costaricensis in Brazil, its clinical presentation and pathology; and proposed diagnostic criteria and case definitions for abdominal angiostrongyliasis (AA). Southern and southeastern Brazilian regions are the main endemic areas, and AA affects both genders and all age groups. A review of all 23 published reports of 51 Brazilian patients highlighted the following features that were subsequently classified as minor diagnostic criteria: abdominal pain, palpable mass in the right lower abdominal quadrant, history of exposure, ileocecal tumor, and intestinal perforation with wall thickening. Proposed major criteria include right lower quadrant abdominal pain, blood eosinophilia, positive serology (antibody detection), intense eosinophilic infiltration that involves all strata of the intestinal wall, eosinophilic granulomatous reaction, and eosinophilic vasculitis. In addition to the definitions of suspected and possible cases according to increasing strength of evidence of this infection, demonstration of worms/eggs/larvae in tissues or Angiostrongylus DNA in tissues or serum are required for a confirmed diagnosis. The application of the proposed criteria and definitions may improve patient management, epidemiologic surveillance, and identification of new endemic areas.

Control line failure in Angiostrongylus vasorum point-of-care serology test in dogs with angiostrongylosis due to suspected hook effect.

OBJECTIVES: Angiostrongylosis is a significant differential for a diverse range of clinical signs in dogs, many of whom present acutely and sometimes with fatal consequences. Point-of-care diagnostic assays include a commercially available Angiostrongylus vasorum qualitative direct lateral flow assay. MATERIALS AND METHODS: Case records from one referral centre from dogs with an invalid A. vasorum lateral flow assay, comprising an absent control line alongside a visible test line, were reviewed. As control line failure was hypothesised to be due to antigen excess; where available the A. vasorum lateral flow assay was repeated using dilutions of the original serum. RESULTS: Six dogs had an invalid A. vasorum lateral flow assay result. Five dogs had presented with acute-onset, severe clinical disease consistent with angiostrongylosis, and one dog was a clinically healthy in-contact. Clinical suspicion of angiostrongylosis was confirmed using alternative diagnostic testing and/or response to treatment. Repetition of the A. vasorum lateral flow assay, in four cases, using diluted plasma (10% to 12.5% v/v) resulted in the appearance of a control line alongside the visible test line. CLINICAL SIGNIFICANCE: A heavy burden of A. vasorum infection resulting in angiostrongylosis should be suspected in dogs with compatible clinical signs and an invalid A. vasorum lateral flow assay result due to control failure alongside a visible test line. Repetition of the test with a diluted serum may be considered to account for the hook effect, also known as the postzone phenomenon, as a possible cause.

Angiostrongylus dujardini infection in a coconut lorikeet (Trichoglossus haematodus) from a zoological garden in Switzerland.

Angiostrongylus spp. (Metastrongyloidea) can cause severe disease in several animal species and humans. This report describes an infection with Angiostrongylus dujardini in a captive coconut lorikeet (Trichoglossus haematodus) from a zoo in Switzerland. The bird was reported being attacked by conspecifics, removed from the flock, and hospitalized. It showed lethargy, moderately reduced body condition, and lack of reaction to visual stimuli. Analgesic and antibiotic treatment were initiated but because of worsening of its general condition, the bird was euthanized the following day. Necropsy revealed multifocal, subcutaneous hemorrhages, diffusely reddened lungs and a moderately dilated right heart with several intraluminal nematodes embedded in a coagulum. Four worms were collected and microscopically examined. They were identified as adult females, measuring 19-21 mm long x 0.4-0.5 mm wide, with general morphological and morphometric characteristics consistent with angiostrongylid nematodes. In lung sections, multifocal collection of thin-walled embryonated eggs in variable stages of development was observed along with fully developed nematode larvae within the lumina of alveoli and lung vessels. Associated granulomatous infiltrates indicated a severe, multifocal, chronic, granulomatous pneumonia. The diagnosis of A. dujardini infection was formulated by morphological examination of adult and larval stages, supported by molecular analysis (PCR-amplification and sequencing of the ITS2, 5.8S and 28S rDNA flanking regions). This is the first report of A. dujardini infection in an avian species, providing evidence that birds can serve as accidental hosts of this parasite in addition to mammals, and that the parasite can reach maturity and multiply in the avian cardiorespiratory system.

A Taq-Man-based multiplex quantitative PCR for the simultaneous detection and quantification of Angiostrongylus vasorum, Crenosoma vulpis, and species of respiratory capillarids in canids.

In recent years, Angiostrongylus vasorum, Crenosoma vulpis, Eucoleus aerophilus (syn. Capillaria aerophila) and Eucoleus boehmi (syn. Capillaria boehmi), commonly referred to as canine lungworms, have gained a growing interest worldwide as the result of their geographical expansion. Each of these nematode species differs considerably in its biology and pathogenicity. Despite their impact on dogs' health, these parasites are often underdiagnosed owing to diagnostic challenges. Here, we describe the development and validation of a Taq-Man-based multiplex quantitative PCR (qPCR) for the simultaneous detection of the main species of canine lungworms in faeces of infected dogs. Using 10-fold serial dilutions of synthetic gene block fragments containing individual sequence targets of each lungworm species, the analytical sensitivity of the assay ascertained was 1.84 ng/µl for A. vasorum, 3.08 ng/µl for C. vulpis and 0.79 ng/µl for Eucoleus spp. The sensitivity of the assays and their ability to detect mixed species infections were compared with microscopy-based techniques (faecal floatation and Baermann technique) applied to faecal samples submitted for lungworm testing through an accredited diagnostic laboratory at the Institute of Parasitology, University of Zurich, Switzerland, and from community dogs as part of a research project on canine endoparasites in Cambodia. The multiplex qPCR displayed high diagnostic sensitivity (42/46, 91.3%; 95% Confidence Interval (CI): 79.1-97.1%) and a diagnostic specificity of 100% (45/45, 95% CI: 90.6-100%), and was able to detect 42.9% additional mixed lungworm species infections compared with microscopy-based methods. Kappa statistics showed substantial agreement between the qPCRs and microscopy for mixed infections (κ = 0.72, 95% CI: 0.4-1) and Eucoleus spp. (κ = 0.65, 95% CI: 0.45-0.85) and almost perfect agreement for C. vulpis (κ = 0.85, 95% CI: 0.63-1) and A. vasorum (κ = 0.92, 95% CI: 0.84-1). This multiplex qPCR enables timely, accurate, and sensitive diagnosis of canine lungworm species in faecal samples and can be used to monitor the geographical distribution and emergence of these parasitic species, globally.

Comparative analysis of diagnostic methods and risk factors for Aelurostrongylus abstrusus infection in brazilian cats.

This study aimed to prospectively evaluate the risk factors of infection by Aelurostrongylus abstrusus in Brazilian cats with cough and/or radiographic changes, using as diagnostic tools the Baermann method (BM), polymerase chain reaction (PCR) of feces, bronchoalveolar lavage fluid (BALF), and cytology. Forty-three cats that were presented with cough or lung radiographic abnormalities compatible with bronchoalveolar disease were included in the study. After clinical evaluation, feces samples were collected to investigate lungworm parasitism through BM and PCR. BALF was performed to provide samples for cytology, bacteriology, and fungal culture. Stool PCR was considered the gold standard for diagnosis tests, and the other methods were evaluated by their agreement. PCR presented 74% (32/43) of positivity for A. abstrusus, while in the BM, 41% (18/43) were positive. BM showed sensitivity of 56.25% and specificity of 100% when compared with PCR. No larva was found in the cytological evaluation of 21 BALF samples. Lungworm is an important cause of bronchopulmonary disease in domestic cats in Brazil and should be included as a differential diagnosis when a cat is presented with cough or radiographic abnormalities. BM is a sensitive, non-invasive, and cheap technique to diagnose the disease, but it is not as sensitive as PCR.

[Progress of researches on the role and mechanisms of non - coding RNA in Angiostrongylus cantonensis infection].

Angiostrongylus cantonensis is a food-borne zoonotic parasite, and human infection may cause eosinophilic meningitis. Non-coding RNAs (ncRNAs) may regulate physiological and pathological processes at multiple biological levels; however, there are few studies pertaining to the regulatory role of ncRNAs in A. cantonensis infection. Based on publications retrieved from PubMed, Wanfang Data and CNKI, the regulatory role of ncRNAs in A. cantonensis infections mainly includes immune responses, cell apoptosis and signaling transduction, and ncRNAs may serve as biomarkers for diagnosis of angiostrongyliasis. This review summarizes the main roles of ncRNAs in A. cantonensis infections and the underlying mechanisms, so as to provide insights into diagnosis and treatment of angiostrongyliasis.

[Progress of researches on techniques for detection of Angiostrongylus cantonensis in intermediate host snails].

Angiostrongyliasis cantonensis is an emerging infectious disease in China. Snails are intermediate hosts of Angiostrongylus cantonensis and play a critical role in the transmission of angiostrongyliasis cantonensis. Detection of A. cantonensis in snails is an important part of epidemiological surveys. Currently, the rapid developments in the techniques for detection of A. cantonensis in snails facilitate the surveillance of angiostrongyliasis cantonensis and provide an important support for angiostrongyliasis cantonensis prevention and control. This review summarizes the advances in the techniques for detection of A. cantonensis in snails.

Diagnostic challenges for Aelurostrongylus abstrusus infection in cats from endemic areas in Italy.

BACKGROUND: The lungworm Aelurostrongylus abstrusus infects wild and domestic feline species worldwide and is considered a primary respiratory parasite of cats. Definitive diagnosis is based on the identification of first-stage larvae (L1s) released in faeces approximately 5 to 6 weeks after infection. More recently, serology has been shown to be a diagnostic alternative for A. abstrusus infection in cats. The present study aimed at evaluating the diagnostic performance of serological antibody detection compared to faecal examination for A. abstrusus infection in a population of cats with known infection status from endemic areas in Italy and to identify factors (larval scores, age, co-infections with other helminths) that may influence test sensitivity and specificity of serology. METHODS: All cats resulting positive using the Baermann technique (n = 78) were tested with the A. abstrusus ELISA. An additional 90 serum samples from cats living in three geographical areas with infection prevalence > 10%, but that resulted negative on Baermann, were also tested. RESULTS: Among 78 cats copromicroscopically positive for L1s of A. abstrusus (Group 1), 29 (37.2%) were seropositive in ELISA. Of the 90 cats from Group 2 (cats living in three geographical areas in Italy with A. abstrusus prevalence > than 10%, but negative on Baermann examination), 11 (12.2%) were positive on ELISA. The overall seroprevalence was 23.8%. There was no statistical difference either between average optical density (OD) values of cats excreting > 100 L1s vs. cats excreting < 100 L1s (0.84 vs. 0.66; P value = 0.3247) or comparing the OD values with age of infected cats. Few Baermann-negative cats positive for Toxocara cati or hookworms were seropositive, supporting lack of cross-reactivity to these nematodes. CONCLUSIONS: Results from the present study suggest that relying solely on faecal examination may underestimate prevalence of A. abstrusus infection in cats and that field surveys based on antibody detection are useful for establishing true prevalence of infected and/or exposed animals.

Immunodiagnostic Detection of Angiostrongylus cantonensis Exposure on Hawaii Island Using Isogeographic 31-kDa Antigen.

Angiostrongylus cantonensis is the leading cause of neuroangiostrongyliasis worldwide, and east Hawaii Island is a hotspot for the disease in the United States. A combination of glycoproteins with molecular weight of 31 kDa has been used as antigen to evaluate antibody response in human serum samples in Thailand with high specificity and sensitivity. In a previous pilot study, the Thailand-isolated 31-kDa proteins showed efficacy in dot-blot tests using serum samples from 435 human volunteers on Hawaii Island. However, we hypothesized that native antigen isolated from Hawaii A. cantonensis may exhibit higher specificity than the Thailand-isolated 31-kDa antigen due to potential minor variation in epitopes between isolates. In this study, 31-kDa glycoproteins were isolated by sodium dodecyl-sulfate polyacrylamide gel electrophoresis from adult A. cantonensis nematodes collected from rats captured on east Hawaii Island. The resultant proteins were purified by electroelution, pooled, bioanalyzed, and quantified. A subset of 148 samples from human participants of the original cohort of 435 was consented for this study, including 12 of the original 15 clinically diagnosed participants. Results of ELISA using the Hawaii-isolated 31-kDa antigen were compared with results of the same serum samples previously tested with both crude Hawaii antigen ELISA and Thailand 31-kDa antigen dot blot. This study shows a seroprevalence in the general population of East Hawaii Island of 25.0%, similar to previous findings of 23.8% seroprevalence in this cohort using crude antigen from Hawaii A. cantonensis and 26.5% using Thailand 31-kDa antigen.

Angie-LAMP for diagnosis of human eosinophilic meningitis using dog as proxy: A LAMP assay for Angiostrongylus cantonensis DNA in cerebrospinal fluid.

BACKGROUND: Angiostrongylus cantonensis (rat lungworm) is recognised as the leading cause of human eosinophilic meningitis, a serious condition observed when nematode larvae migrate through the CNS. Canine Neural Angiostrongyliasis (CNA) is the analogous disease in dogs. Both humans and dogs are accidental hosts, and a rapid diagnosis is warranted. A highly sensitive PCR based assay is available but often not readily accessible in many jurisdictions. An alternative DNA amplification assay that would further improve accessibility is needed. This study aimed to assess the diagnostic utility of a newly designed LAMP assay to detect DNA of globally distributed and invasive A. cantonensis and Angiostrongylus mackerrasae, the other neurotropic Angiostrongylus species, which is native to Australia. METHODOLOGY/PRINCIPAL FINDINGS: Cerebrospinal fluid (CSF) from dogs with a presumptive diagnosis of A. cantonensis infection (2020-2022) were received for confirmatory laboratory testing and processed for DNA isolation and ultrasensitive Angiostrongylus qPCR targeting AcanR3390. A newly designed LAMP assay targeting the same gene target was directly compared to the reference ultrasensitive qPCR in a diagnostic laboratory setting to determine the presence of A. cantonensis DNA to diagnose CNA. The LAMP assay (Angie-LAMP) allowed the sensitive detection of A. cantonensis DNA from archived DNA specimens (Kappa = 0.81, 95%CI 0.69-0.92; n = 93) and rapid single-step lysis of archived CSF samples (Kappa = 0.77, 95%CI 0.59-0.94; n = 52). Only A. cantonensis DNA was detected in canine CSF samples, and co-infection with A. mackerrasae using amplicon deep sequencing (ITS-2 rDNA) was not demonstrated. Both SYD.1 and AC13 haplotypes were detected using sequencing of partial cox1. CONCLUSIONS/SIGNIFICANCE: The Angie-LAMP assay is a useful molecular tool for detecting Angiostrongylus DNA in canine CSF and performs comparably to a laboratory Angiostrongylus qPCR. Adaptation of single-step sample lysis improved potential applicability for diagnosis of angiostrongyliasis in a clinical setting for dogs and by extension, to humans.

Improving the detection of Angiostrongylus cantonensis in the brain tissues of mammalian hosts.

Angiostrongylus cantonensis is an invasive nematode parasite that causes eosinophilic meningitis in many vertebrate hosts, including humans. This parasite is spreading rapidly through the six continents, with Europe being the final frontier. Sentinel surveillance may be a cost-effective strategy to monitor the pathogen's arrival to new geographical regions. Necropsy, followed by tissue digestion, is often used to recover helminth parasites from vertebrate host tissues, however, to detect brain parasites, this protocol is poorly utilized. Our brain digestion protocol is easily performed and 1) reduces false positivity and negativity, 2) provides accurate estimates of parasite burden and 3) helps establish a more precise prevalence. Early detection of A. cantonensis increases the efficacy of prevention, treatment, and disease control strategies for susceptible animal populations and humans.

A practical guide for the diagnosis of abdominal angiostrongyliasis caused by the nematode Angiostrongylus costaricensis.

Abdominal angiostrongyliasis (AA) is a severe parasitic infection caused by the nematode Angiostrongylus costaricensis. This disease is characterized by abdominal pain, a strong inflammatory eosinophilic response in the blood and tissues, and eventually intestinal perforation. Diagnosis of AA is challenging since there are no commercially available serological kits for A. costaricensis, and thus, histopathological analysis remains the gold standard. Herein we provide a decision flowchart for clinicians to improve the diagnosis of AA based on a patient's clinical manifestations, laboratory findings, macroscopic observations of the gut lesions, as well as characteristic microscopic alterations in biopsies. A brief discussion of the available polymerase chain reaction and in-house serological methods is also presented. The aim of this mini-review is to improve the diagnosis of AA, which should lead to prompt detection of cases and better estimates of the epidemiology and geographical distribution of A. costaricensis.

Molecular diagnosis of abdominal angiostrongyliasis by PCR using serum samples.

Abdominal angiostrongyliasis (AA) is a zoonotic disease caused by the nematode Angiostrongylus costaricensis, which is endemic in southern Brazil. Humans become infected by ingesting third-stage (L3) larvae and are considered accidental hosts since neither eggs nor first-stage (L1) larvae are found in feces. The definitive diagnosis can be made by histopathologic examination of surgical specimens or intestinal biopsies. The present study assessed the use of PCR to carry out the molecular detection of AA from serum samples. A total of 62 human serum samples were divided into three groups: (i) 28 serum samples from human patients with presumptive histopathological diagnosis of AA; (ii) 23 serum samples from individuals with unknown serology for AA; (iii) 11 serum samples from patients that suffered from different parasitosis were included. The serum samples were initially tested by in-house indirect ELISA and then by PCR. A total of 14 samples were positive by ELISA, and 6 were positive by PCR. Six samples that were negative by ELISA were positive by PCR. Amplicons were sequenced, and Angiostrongylus DNA was confirmed. We conclude that PCR amplification can be used to confirm Angiostrongylus DNA in serum, which is especially important in cases where antibody levels are too low to be detected. It may also serve as a useful target for survey studies.

Immunoanalysis of different antigenic preparations of Angiostrongylus cantonensis for neuroangiostrongyliasis diagnosis improvement.

BACKGROUND: Angiostrongylus cantonensis is the etiological agent of neuroangiostrongyliasis in humans, which is developed in gastropods and vertebrate species, mainly rodents. Human transmission occurs through consumption of molluscs and paratenic hosts infected with L3, and the migration of larvae to the central nervous system causes eosinophilic meningitis. Laboratory diagnosis is based on molecular and immunological tests, using young or adult females as a source of antigens. However, these tests give positive results only after several weeks of symptoms onset and also cross-reactions with others parasite infections may occur. OBJECTIVES: The purpose of this work was to study different antigenic preparations of distinct evolutionary phases of A. cantonensis, in order to improve serological techniques for disease immunodiagnosis. METHODS: For this purpose, antigenic fractions of different evolutionary forms were evaluated by Dot-enzyme-linked immunosorbent assay (Dot-ELISA) and Western blot using serum samples. FINDINGS: All analysed fractions showed reactivity with serum samples from patients with neuroangiostrongyliasis, especially female membrane alkaline (FAM) and female soluble alkaline (FAS) fractions together with female soluble saline (FSS), improving the technique specificity. MAIN CONCLUSIONS: The results point to the possibility of use of raw female antigens in association with alkaline membrane antigens extracted from adult worms to aid in diagnosis and helps initiate neuroangiostrongyliasis surveillance and control actions.

Adult parasite burden and excretion of first-stage larvae of Angiostrongylus vasorum in dogs: Methodologically relevant diagnostic aspects and associations with serological detection of parasite antigen and specific antibodies.

Angiostrongylus vasorum is a widely distributed cardiopulmonary parasite of canids in Europe. Clinical signs in dogs can be highly variable and diagnostically challenging. A correct and early diagnosis is hence indispensable to adequately manage affected patients. First-stage larvae (L1) are excreted in the faeces of definitive hosts and conventionally identified using the Baermann technique. Moreover, ELISAs for the detection of circulating antigen and specific antibodies have been presented. The current study aimed at i) quantitatively assessing larval migration in the Baermann funnel after 12 h and 24 h; ii) investigating the influence of sample storage at 4 °C over the course of three days on the number of detected L1; iii) evaluating potential associations of adult worm burdens with larval shedding in dogs and ELISA optical density (OD) values for circulating parasite antigen and specific antibodies. Faecal samples were obtained from naturally infected dogs (n = 21) and Baermann funnels were set up in duplicate over the course of four consecutive days (days 0-3) starting with the day of sample collection. Funnels were harvested on days 1-4 after 12 and 24 h, respectively, and the number of L1 per gram faeces (LPG) was determined. The LPG did not differ between larval harvest after 12 h from harvest after 24 h. Storage of faecal samples at 4 °C for two and three days entailed a considerable decrease in LPG. Adult worm burdens and larval excretion data from previous experiments demonstrated a correlation between worm burden and LPG. In contrast, no correlations between worm burden and the level of parasite antigen and specific antibody OD values, respectively, were identified. Thus, OD values of both antigen and antibody ELISA did not allow for conclusions on infection intensity reflected by the number of adult parasites. For the detection of L1 in faeces, 12 or 24 h of larval migration time was not discriminating for A. vasorum positivity. Thus, early processing of faecal samples is essential, since larval detection and hence sensitivity of the approach considerably decreased over the course of three days of storage. Therefore, the common recommendation to collect faecal samples for three consecutive days and to subsequently analyse them needs to be reconsidered. The results of this study can be readily translated into precise recommendations for daily practice to adequately assess A. vasorum infected dogs.

A Rare Etiology for Ascending Paralysis in an Infant.

An 11-month-old male infant with ascending paralysis had an unremarkable initial cerebrospinal fluid (CSF) analysis and imaging. Progressive neurological symptoms resulted in repeated CSF sampling, microscopy, and plasma microbial cell-free DNA next-generation sequencing analysis, that in combination with epidemiology, confirmed the diagnosis.

First report of Angiostrongylus vasorum (French heartworm) in red foxes (Vulpes vulpes) on Prince Edward Island.

Objective: To identify first-stage nematode larvae (L1) recovered from a red fox scat sample and adult female worms recovered from 2 red fox lungs at necropsy, using published molecular methods to confirm a morphological diagnosis of Angiostrongylus vasorum (French heartworm). Animal: Red fox (Vulpes vulpes). Procedure: Nematode larvae recovered from a Baermann examination survey of wild canid scats (n = 101) conducted from January 2017 to August 2020, were identified by size and morphology and subjected to PCR and DNA sequencing of the small subunit (SSU) rRNA gene, the large subunit (LSU) rRNA gene, or the second internal transcribed spacer (ITS2). In addition, these techniques were applied to adult female worms recovered from the heart/lungs of 2 red foxes (obtained from PEI trappers and stored frozen at -20°C since December of 2018 and 2020). Results: Size and morphology of L1 recovered by Baermann examination from a wild canid scat sample (presumed to be red fox) collected near Montague, PEI and adult female worms recovered at necropsy from 2 red fox carcasses were identified as A. vasorum. Molecular analysis confirmed the larvae and adult worms were A. vasorum. Conclusion: These findings indicated that A. vasorum has become endemic in the red fox population on PEI. Clinical relevance: Angiostrongylus vasorum infection is potentially fatal in dogs. Veterinarians and regional diagnostic laboratories in the Maritime provinces should consider the possibility of A. vasorum infection in dogs with clinical signs of cardiopulmonary and/or central nervous system disease or bleeding disorders.

Objectif: Identifier les larves de nématodes de premier stade (L1) récupérées à partir d'un échantillon d'excréments de renard roux et les vers femelles adultes récupérés à partir de deux poumons de renard roux à l'autopsie, en utilisant des méthodes moléculaires publiées pour confirmer un diagnostic morphologique d'Angiostrongylus vasorum (ver du coeur français). Animal: Renard roux (Vulpis vulpis). Procédure: Les larves de nématodes récupérées lors d'une enquête sur des excréments de canidés sauvages (n = 101) par examen Baermann menée de janvier 2017 à août 2020, ont été identifiées par taille et morphologie et soumises à la PCR et au séquençage de DNA de la petite sous-unité (SSU) du gène de rRNA, de la grande sous-unité (LSU) du gène de rRNA ou du deuxième espaceur interne transcrit (ITS2). De plus, ces techniques ont été appliquées à des vers femelles adultes récupérés du coeur/poumons de deux renards roux (obtenus auprès de trappeurs de l'Î.-P.-É. et conservés congelés à −20 °C depuis décembre 2018 et 2020). Résultats: La taille et la morphologie de L1 récupérées par examen Baermann à partir d'un échantillon d'excréments de canidés sauvages (présumé être du renard roux) prélevé près de Montague, Î.-P.-É. et des vers adultes femelles récupérés des carcasses lors de la nécropsie de deux renards roux ont été identifiés comme étant A. vasorum. L'analyse moléculaire a confirmé que les larves et les vers adultes étaient A. vasorum. Conclusion: Ces résultats indiquent qu'A. vasorum est devenu endémique dans la population de renards roux de l'Î.-P.-É. Pertinence clinique: L'infection à A. vasorum est potentiellement mortelle chez le chien. Les vétérinaires et les laboratoires de diagnostic régionaux des provinces maritimes devraient envisager la possibilité d'une infection à A. vasorum chez les chiens présentant des signes cliniques de maladie cardio-pulmonaire et/ou du système nerveux central ou de troubles de la coagulation.(Traduit par Dr Serge Messier).

Angiostrongylus cantonensis in a Red Ruffed Lemur at a Zoo, Louisiana, USA.

A red ruffed lemur (Varecia rubra) from a zoo in Louisiana, USA, was euthanized for worsening paresis. Brain and spinal cord histology identified eosinophilic meningoencephalomyelitis with intralesional adult Angiostrongylus sp. nematodes. PCR and sequencing confirmed A. cantonensis infection, indicating this parasite constitutes an emerging zoonosis in the southeastern United States.

Infection with the fox lungworm (Crenosoma vulpis) in two dogs from New England - Two clinical reports and updated geographic distribution in North America.

Crenosoma vulpis, the fox lungworm, is a helminth parasite endemic to the fox population of New England. Domestic dogs are susceptible to infection via ingestion of snails and slugs. Two dogs from New England were diagnosed with C. vulpis. The predominant clinical sign in both dogs was a chronic cough. Treatment with steroids and antibiotics only temporarily relieved clinical signs. Thoracic radiographs in both dogs revealed bronchial patterns. Endotracheal washes were performed in each dog revealing marked, mixed inflammation consisting mainly of neutrophils with eosinophils in lesser numbers. Helminth larvae could also be visualized on cytology. A fecal flotation revealed helminth larvae in one dog but failed to identify larvae in the second dog. The diagnosis of C. vulpis was confirmed via PCR analysis and sequencing of samples from both endotracheal washes. One dog was treated with fenbendazole (50 mg/kg PO q24h for 14 days), enrofloxacin (13 mg/kg PO q 24 h for 5 days), and a tapering protocol of prednisone (20 mg PO q12h for 5 days, 20 mg PO q24h for 5 days, then 20 mg PO q48h for 10 days). The second dog was treated with fenbendazole (50 mg/kg PO q24h for 10 days) with an additional 7 days of febantel and two doses of milbemycin, achieving complete resolution of clinical signs. This lungworm is becoming increasingly more prevalent in domestic dogs worldwide and may be more prevalent in New England than previously thought. Veterinary practitioners of New England should include this respiratory helminth as a differential in dogs with respiratory signs, and respiratory washes and Baermann fecal examinations are warranted in dogs presenting with non-specific respiratory clinical signs.