Canine Leishmaniasis Control in the Context of One Health.

Dogs are the main reservoir of Leishmania infantum and in some countries have been regularly culled as part of government policy to control visceral leishmaniasis. At the 13th Symposium of the Companion Vector-Borne Diseases World Forum in Windsor, UK, March 19-22, 2018, we consolidated a consensus statement regarding the usefulness of dog culling as a means of controlling visceral leishmaniasis. The statement highlighted the futility of culling infected dogs, whether healthy or sick, as a measure to control the domestic reservoir of L. infantum and reduce the risk for visceral leishmaniasis.

Detection and molecular characterization of Acanthamoeba spp. in stray cats from Madrid, Spain.

Acanthamoeba spp. is a widespread protozoan that has been isolated from air, dust, soil, water and biological samples. An opportunistic pathogen of humans and animals, it may cause ocular keratitis, encephalitis, and even multisystem disease. The frequency of Acanthamoeba in animals is unknown. The aim of present study was determine the presence of Acanthamoeba spp. in immunocompromised stray cats - animals possibly more likely to harbour the infection given their immunocompromised status and frequenting of contaminated environments. Of 307 cats examined, 55 were positive for feline immunodeficiency virus and/or feline leukaemia virus and therefore included in the study. Corneal scrapings were obtained to isolate Acanthamoeba spp. by culture and molecular detection by conventional and real time PCR. None of the samples examined directly by molecular methods were positive for Acanthamoeba spp. However, two (3.6%) cases of the cultured samples provided positive results, which were confirmed by subsequent molecular analysis. Sequencing assigned one isolate to genotype T4 and the other to T2. Since Acanthamoeba spp. may also infect animals and humans, the present findings may raise some public health and veterinary concerns.

Use of domperidone in canine visceral leishmaniasis: gaps in veterinary knowledge and epidemiological implications.

A pivotal strategy to decrease the risk of visceral leishmaniasis in humans is to control the infection and disease progression in dogs, the domestic reservoir of Leishmania infantum (L. chagasi). Immunotherapy is a viable approach to treat sick dogs because cell-mediated immunity is the principal defense mechanism against L. infantum. Domperidone is an immune-stimulatory drug increasingly used in veterinary medicine as a prophylactic or immunotherapeutic agent. Domperidone treatment has shown to prevent overt disease or improve the clinical condition of infected dogs. However, veterinarians should be aware of the potential cardiotoxicity of domperidone when given together with drugs that inhibit CYP450s liver enzymes or those that prolong the QT interval. On the other hand, learning whether domperidone treatment significantly decreases dog infectivity to sand fly vectors is of capital importance since this result should have a palpable impact on the infection risk of humans living in regions endemic for visceral leishmaniasis.

DNA sequence analysis suggests that cytb-nd1 PCR-RFLP may not be applicable to sandfly species identification throughout the Mediterranean region.

Molecular methods are increasingly used for both species identification of sandflies and assessment of their population structure. In general, they are based on DNA sequence analysis of targets previously amplified by PCR. However, this approach requires access to DNA sequence facilities, and in some circumstances, it is time-consuming. Though DNA sequencing provides the most reliable information, other downstream PCR applications are explored to assist in species identification. Thus, it has been recently proposed that the amplification of a DNA region encompassing partially both the cytochrome-B (cytb) and the NADH dehydrogenase 1 (nd1) genes followed by RFLP analysis with the restriction enzyme Ase I allows the rapid identification of the most prevalent species of phlebotomine sandflies in the Mediterranean region. In order to confirm the suitability of this method, we collected, processed, and molecularly analyzed a total of 155 sandflies belonging to four species including Phlebotomus ariasi, P. papatasi, P. perniciosus, and Sergentomyia minuta from different regions in Spain. This data set was completed with DNA sequences available at the GenBank for species prevalent in the Mediterranean basin and the Middle East. Additionally, DNA sequences from 13 different phlebotomine species (P. ariasi, P. balcanicus, P. caucasicus, P. chabaudi, P. chadlii, P. longicuspis, P. neglectus, P. papatasi, P. perfiliewi, P. perniciosus, P. riouxi, P. sergenti, and S. minuta), from 19 countries, were added to the data set. Overall, our molecular data revealed that this PCR-RFLP method does not provide a unique and specific profile for each phlebotomine species tested. Intraspecific variability and similar RFLP patterns were frequently observed among the species tested. Our data suggest that this method may not be applicable throughout the Mediterranean region as previously proposed. Other molecular approaches like DNA barcoding or phylogenetic analyses would allow a more precise molecular species identification.

LEISHMANIA INFANTUM INFECTION IN BENNETT'S WALLABIES (MACROPUS RUFOGRISEUS RUFOGRISEUS) IN A SPANISH WILDLIFE PARK.

Although dogs are the main reservoir for human Leishmania infantum infection, the disease has also been reported in other domestic and wild mammals. In 2011, a fatal case of naturally acquired leishmaniosis was described for the first time in a Bennett's wallaby (Macropus rufogriseus rufogriseus) kept in a wildlife park in Madrid (Spain). This study was designed to assess the infection status of twelve Bennett's wallabies in the same park one year after this incident. Phlebotomus perniciosus, the main vector of L. infantum in Spain, was screened for using sticky and Centers for Disease Control miniature light traps. L. infantum infection was confirmed by molecular diagnosis in four animals, but only one wallaby returned a positive serology result. The presence of the sand fly vector was also confirmed in this habitat. These results suggest that the first case of L. infantum in a wallaby in this park was not an isolated incident and stress the need for further work to determine the role of this parasite in the morbidity and mortality of these macropods. Madrid was recently the scene of an outbreak of human cutaneous and visceral leishmaniosis. Epidemiological studies have so far revealed the widespread presence of L. infantum infection in animals other than the dog. Our ongoing work suggests a risk of L. infantum infection not only among captive animals in Madrid, but also among threatened species or even species that are already extinct in the wild.

First study on efficacy and tolerability of a new alkylphosphocholine molecule (oleylphosphocholine-OlPC) in the treatment of canine leishmaniosis due to Leishmania infantum.

The alkylphosphocholine oleylphosphocholine (OlPC) represents a potential new therapy for the treatment of canine leishmaniosis caused by Leishmania infantum. The aim of the present study was to evaluate the efficacy and safety of OlPC in a small cohort of dogs naturally infected with L. infantum and defined as clinically sick (LeishVet stages II and III). A total of eight dogs were included in the study and were treated orally with 4 mg/kg OlPC for 14 days. Dogs were assessed at the clinical and parasitological level at four time points during a total follow-up period of 90 days (before treatment and at 15, 30, and 90 days post-treatment onset). Ln-PCR, real-time quantitative PCR, antibody testing (IFAT), and culture of bone marrow aspirates were evaluated at the four time points. OlPC treatment induced a rapid and satisfactory clinical recovery in terms of clinical score reduction and weight gain, and treatment efficacy was found to be associated with a decrease in bone marrow parasitic load. Serological titers measured by IFAT were stable in any of the treated dogs at any time point after treatment. OlPC was well tolerated and no severe adverse events were noted in any of the treated dogs; even some dogs showed slight intestinal disorders. This proof-of-principle study is the first to show that short oral treatment with OlPC improves clinical signs of canine L. infantum leishmaniosis, highlighting the need to perform additional studies to optimize the dosing regimen and to assess long-term treatment efficacy of this drug.

Exploring the impact of epidemiological and clinical factors on the progression of canine leishmaniosis by statistical and whole genome analyses: from breed predisposition to comorbidities.

Canine leishmaniosis (CanL), caused by Leishmania infantum, is a complex disease of growing importance in Europe. Clinical manifestations result from the down-modulation of the host immune response through multiple host-parasite interactions. Although several factors might influence CanL progression, this is the first known study evaluating risk factors for its different clinical stages in a large referral hospital population (n = 35.669) from an endemic area, over a 20 year period. Genome-wide scans for selection signatures were also conducted to explore the genomic component of clinical susceptibility to L. infantum infection. The prevalence of CanL was 3.2% (16.7% stage I; 43.6% stage II; 32.1% stage III; 7.6% stage IV). Dog breed (crossbreed), bodyweight (<10 kg), living conditions (indoors), regular deworming treatment, and being vaccinated against Leishmania significantly decreased the transmission risk and the risk for developing severe clinical forms. Conversely, the detection of comorbidities was associated with advanced clinical forms, particularly chronic kidney disease, neoplasia, cryptorchidism, infectious tracheobronchitis and urate urolithiasis, although those did not impact the clinical outcome. Significant associations between an increased risk of severe clinical stages and findings in the anamnesis (renal or skin-related manifestations) and physical examination (ocular findings) were also detected, highlighting their diagnostic value in referred cases of CanL. Sixteen breeds were found to be significantly more susceptible to developing severe stages of leishmaniosis (e.g. Great Dane, Rottweiler, English Springer Spaniel, Boxer, American Staffordshire Terrier, Golden Retriever), while 20 breeds displayed a clinical resistantance phenotype and, thus, are more likely to mount an efficient immune response against L. infantum (e.g. Pointer, Samoyed, Spanish Mastiff, Spanish Greyhound, English Setter, Siberian Husky). Genomic analyses of these breeds retrieved 12 regions under selection, 63 candidate genes and pinpointed multiple biological pathways such as the IRE1 branch of the unfolded protein response, which could play a critical role in clinical susceptibility to L. infantum infection.

Cystoisospora spp. infection at a dog breeding facility in the Madrid region: Infection rate and clinical management based on toltrazuril metaphylaxis.

Canine coccidiosis caused by Cystoisospora canis and Cystoisospora ohioensis-complex is common in kennels. While often underestimated, coccidiosis may cause severe clinical signs in puppies and sometimes even lead to death, so preventative measures are important. This study examines Cystoisospora spp. infection at a Labrador retriever breeding facility in Madrid, Spain. To identify environmental factors associated with infection, dams were examined throughout a reproductive cycle (from oestrus to 60 days postpartum) and their puppies during their first 60 days of life. Also assessed was the efficacy of combined treatment with emodepside (0.9 mg/ml) and toltrazuril (18 mg/ml) at a dose of 0.5 ml/kg of weight, equivalent to 0.45 mg/kg and 9 mg/kg, respectively, in puppies on day 35 of life. Oocyst shedding was detected in 4.6-18.6% of 45 dams examined and in 2.2-9.1% of their litters (315 puppies). In both cases, peak opg elimination was recorded on day 30 postpartum/of life. The species of Cystoisospora detected were C. canis (91.3%) and C. ohioensis-complex (8.7%). While in both dams and puppies opg counts were higher in autumn when rainfall was at its highest, correlation between opg and rainfall emerged as significant only in puppies (p = 0.031). The treatment of 35 day-old puppies with toltrazuril was 100% effective in controlling this infection in the kennel. Our findings therefore suggest the need for a strict hygiene regime and the use of toltrazuril as blanket treatment to reduce Cystoisospora transmission in dog breeding facilities.

Urinary Tamm-Horsfall protein excretion is a potential early biomarker of renal distal tubular damage in canine leishmaniosis.

This study evaluates distal tubular damage in early stages of renal disease in dogs with naturally acquired leishmaniosis. Pherograms of urinary proteins separated in vertical electrophoresis system (SDS-PAGE) were evaluated. Peptide fingerprint and fragmentation (MALDI-TOF TOF) identified bands located at 100 and 60 kDa as Tamm-Horsfall protein (THP) and albumin, respectively. The variables examined were: urine protein to creatinine ratio (UPC), total number of bands, quantification of THP urinary excretion through the optical density (OD %) of bands located at 100 kDa, blood creatinine, and urine specific gravity (USG). Positive correlation was found between UPC and the number of bands (ρ = 0.75849, P = <0.0001). Negative correlation was identified between UPC and OD % of 100 kDa bands (ρ = -0.85332, P = <0.0001), and the number of bands and OD % of 100 kDa bands (ρ = -0.74479, P = <0.0001). The area under the ROC curve was 0.991 (95 % CI, 0.976-1). The optimal cut-off UPC that better discriminated between urines with high or low OD% of THP was 0.46 with 92.6 % sensitivity and 96.2 % specificity. Our findings indicate that non azotemic dogs with borderline proteinuria might excrete low amount of THP, which could suggest tubular damage in early stages of chronic kidney disease.

Corrigendum: Clinical validation of circulating immune complexes for use as a diagnostic marker of canine leishmaniosis.

[This corrects the article DOI: 10.3389/fvets.2024.1368929.].

Clinical validation of circulating immune complexes for use as a diagnostic marker of canine leishmaniosis.

Introduction: Canine leishmaniosis (CanL) is a systemic disease that affects dogs. When multiplication of the parasite cannot be controlled, dogs consistently show high levels of antigen and IgG antibodies, which lead to the formation of circulating immune complexes (CIC). Timely intervention to reduce the parasite load and CIC levels is crucial for preventing irreversible organ damage. However, a diagnostic test to quantify CIC levels is currently lacking. Methods: In this real-world study, we aimed to examine the performance of a new ELISA to measure CIC levels in dogs naturally infected with Leishmania infantum. Thirty-four dogs were treated according to their clinical condition and followed for 360 days. Before (day 0) and after treatment (days 30, 90, 180, 270, and 360), all dogs underwent a physical examination, and blood samples were obtained for CBC, biochemical profile, serum protein electrophoresis and IFAT. Serum PEG-precipitated CIC were determined by ELISA. Results: Our results indicate higher CIC levels in dogs in advanced disease stages showing higher antibody titres (p < 0.0001, r = 0.735), anemia (p < 0.0001), dysproteinemia (p < 0.0001), and proteinuria (p = 0.004). Importantly, dogs responding well to treatment exhibited declining CIC levels (p < 0.0001), while in poor responders and those experiencing relapses, CIC were consistently elevated. CIC emerged as a robust discriminator of relapse, with an area under the curve (AUC) of 0.808. The optimal cut-off to accurately identify relapse was an optical density of 1.539. Discussion: Our findings suggest that declining CIC levels should be expected in dogs showing a favorable treatment response. Conversely, in dogs displaying a poor response and recurrent clinical relapses, CIC levels will be high, emphasizing the need for vigilant monitoring. These findings suggest that CIC could serve as a valuable biomarker for disease progression, treatment efficacy, and relapse detection in CanL. Our study contributes to enhancing diagnostic approaches for CanL and underscores the potential of CIC as a complementary tool in veterinary practice. As we move forward, larger studies will be essential to confirm these findings and establish definitive cut-offs for clinical application.

Performance of a point-of-care test for the detection of anti-Leishmania infantum antibodies is associated with immunofluorescent antibody titer and clinical stage of leishmaniosis in dogs from endemic regions.

Canine leishmaniosis (CanL) is caused by the protozoal parasite Leishmania infantum, which is transmitted by sand flies in warm climates across the world. Because dogs are considered a primary domestic reservoir for the parasite that causes leishmaniosis in humans, it is important from a One Health perspective that CanL be properly managed. In endemic regions, CanL is a common differential diagnosis in sick dogs because the clinical signs and clinicopathological disorders of the disease are non-specific, variable, and may overlap those of other common conditions. Diagnosis is based on the presence of compatible clinical signs, laboratory abnormalities, and confirmation by serological and parasitological evidence of infection. Here, we describe the performance of a point-of-care (POC) immunoassay that uses recombinant antigens to detect canine anti- L. infantum antibodies in a convenience sample set from a diagnostic laboratory, a group of canine patients with clinical staging, and in apparently healthy dogs from endemic areas. An immunofluorescence antibody test (IFAT) was used as the semiquantitative reference method. In the convenience sample set with high IFAT titers (≥ 1:800), the POC immunoassay demonstrated perfect agreement with IFAT (100%; 90/90). Using samples from dogs staged as either LeishVet Stage 2 or 3 or LeishVet Stage 1, positive agreement of the POC immunoassay with the IFAT was 98.8% (82/83) and 83.8% (31/37), respectively. The negative agreement with IFAT was 98.9% (272/275) in apparently healthy dogs from endemic areas of Greece and Italy. Since the performance of the POC immunoassay was associated with IFAT titer and clinical stage of CanL, the test may help veterinarians when determining if CanL is likely responsible for a patient's clinical picture or when evaluating an apparently healthy patient prior to vaccination.

ParSCo: celebrating 10 years of a unique parasitology summer course.

ParSCo (Parasitology Summer Course) is an intense, 1-week-long summer course organized by the Parasitology Unit of the Department of Veterinary Medicine, University of Bari, Italy, with the support of the World Association for the Advancement of Veterinary Parasitology (WAAVP), the European Veterinary Parasitology College (EVPC) and Parasites and Vectors. The course, which is conducted in southern Italy, is planned for parasitologists and post-graduate students working in the field of parasitology. The course consists of theoretical and practical lessons, which include the collection, identification and diagnosis of parasites of pets, livestock and wildlife. The participants in ParSCo are afforded the opportunity to be involved in clinical examination and sample collection for the diagnosis of parasitic diseases (e.g. leishmaniosis, thelaziosis and many tick-borne diseases) present in the Mediterranean Basin. The course is conducted at Casa di Caccia, a hunting lodge situated in the Gallipoli Cognato Forest near the Basento River in the Basilicata region in southern Italy. In addition to the training purpose, ParSCo is a great opportunity for sharing knowledge and expertise while becoming part of the parasitology community in a pleasant environment. In this editorial, we share some information and celebrate 10 years of ParSCo, looking forward to forthcoming sessions of this unique parasitology summer course.

Species diversity of dermal microfilariae of the genus Cercopithifilaria infesting dogs in the Mediterranean region.

Following the recent description of microfilariae of a Cercopithifilaria sp. in a dog from Sicily, Italy, (herein after referred to as Cercopithifilaria sp. I), numerous skin samples were collected from dogs in the Mediterranean region. In addition to Cercopithifilaria sp. I (185·7 ± 7·2 µm long), microfilariae of 2 other species were identified, namely Cercopithifilaria grassii (651·7 ± 23·6 µm long) and a yet undescribed microfilaria, Cercopithifilaria sp. II (264·4 ± 20·2 µm long, with evident lateral alae). The morphological differentiation among the 3 species of dermal microfilariae was confirmed by differences in cytochrome c oxidase subunit 1 and ribosomal 12S sequences examined (mean level of interspecific pairwise distance of 11·4%, and 17·7%, respectively). Phylogenetic analyses were concordant in clustering these with other sequences of Cercopithifilaria spp. to the exclusion of Dirofilaria spp., Onchocerca spp. and Acanthocheilonema spp. Dermal microfilariae collected (n = 132) were morphologically identified as Cercopithifilaria sp. I (n = 108, 81·8%), Cercopithifilaria sp. II (n = 17, 12·9%), whereas only 7 (5·3%) were identified as C. grassii. Mixed infestations were detected in all sites examined. The great diversity of these neglected filarioids in dogs is of biological interest, considering the complex interactions occurring among hosts, ticks and Cercopithifilaria spp. in different environments.

Serological survey of Leishmania infantum in apparently healthy dogs in different areas of Spain.

BACKGROUND: Canine leishmaniosis caused by Leishmania infantum is an endemic disease in Spain. The dog is considered the main reservoir, and the detection of specific serum antibodies against L. infantum antigen is the most used technique for diagnosing this infection. The LEISCAN LEISHMANIA ELISA test is a commercialized enzyme-linked immunosorbent assay for the detection and measurement of canine anti-Leishmania serum antibodies. OBJECTIVES: The aim of this study was to assess seroprevalence results of apparently healthy dogs in different areas of Spain using LEISCAN. METHODS: Collection of sera from 5451 apparently healthy dogs was performed between 2020 and 2021 in different areas of Spain. Dogs were of adult age (≥12 months), were not previously diagnosed with clinical leishmaniosis or vaccinated against Leishmania and did not present clinical signs compatible with L. infantum infection. LEISCAN was performed following the manufacturer's protocol. RESULTS: The overall seroprevalence was 5.5%. The highest seroprevalences were found in the Southeast of Spain: Comunidad Valenciana (14%) and Región de Murcia (14%), whereas the lowest seroprevalences were found in Northern Spain: Galicia (1%), Navarra (2%) and Castilla y León (2%) (p-value <0.001). CONCLUSIONS: In conclusion, the seroprevalence for L. infantum in apparently healthy dogs in Spain varied from almost no infection to being over 10%.

Hepatozoon species infecting domestic cats from countries of the Mediterranean basin.

Tick-borne diseases (TBDs) are caused by pathogens of human and veterinary concern representing a major public health issue worldwide. Although feline medicine has progressed much in the recent decades, data on feline TBDs (FeTBDs) remain scant. Therefore, this study aimed to assess the prevalence of apicomplexan parasite infections, associated risk factors and clinical-hematological abnormalities in domestic feline populations from countries of the Mediterranean basin. Blood and serum samples from cats (n = 600) living in France, Greece, Israel, Italy, Portugal and Spain were collected along with animal data (i.e., age, sex, breed, housing conditions and geographical origin), clinical signs and laboratory blood test parameters. Cats were grouped according to their age as kitten (up to one year), young (between one and six years), mature (between seven and ten years) and senior (older than ten years). Blood samples were tested for Hepatozoon spp. and piroplasmids by conventional PCR targeting 18S rRNA gene. The overall prevalence of Hepatozoon spp. infection was 14.5%, being significantly higher in cats from Greece (30%) and Portugal (23%), followed by Spain (15%), Israel (15%) and France (4%). Cats from Italy scored negative. Hepatozoon felis was identified in 86 animals, with three different sequence types and H. silvestris was detected in one shelter cat from Portugal. No piroplasmid DNA was amplified. The risk of Hepatozoon spp. infection was related to feline geographical provenience, housing condition and age. No statistical correlation was reported with any clinical signs, while increased alanine aminotransferase (ALT) activity was the only laboratory abnormality significantly associated (p = 0.03) with the infection. Data suggest a high circulation of H. felis, and only occasionally of H. silvestris, within domestic feline populations in the Mediterranean basin, mainly in shelter or free roaming and young cats with asymptomatic or subclinical infection.

A blinded, randomized and controlled multicenter clinical trial to assess the efficacy and safety of Leisguard® as an immunotherapeutic treatment for healthy Leishmania infantum-seropositive dogs.

BACKGROUND: Domperidone (Leisguard®) is an immunomodulatory drug used as a preventive measure in healthy dogs. However, no studies have been published in healthy Leishmania infantum-seropositive dogs. The aim of this study was to evaluate the clinical efficacy and safety of domperidone as immunotherapy in Leishmania-seropositive healthy dogs. METHODS: Sixty-seven dogs were treated with domperidone at 0.5 mg/kg and 44 dogs received placebo, once daily for 4 consecutive weeks. Monthly treatments were repeated every 4 months until the end of the 1-year follow-up period. Veterinary examinations were performed on days 0, 30, 120, 150, 240, 270 and 360. Samples of blood and urine were collected on days 0, 120, 240 and 360 for routine laboratory tests and quantitative in-house ELISA for the detection of L. infantum-specific antibodies. Furthermore, Leishmania real-time PCR and IFN-γ ELISA were performed at day 0 and the end of the study. Dogs that developed disease were withdrawn from the study and classified as sick dogs. Adverse drug reactions were reported. RESULTS: Thirty dogs developed disease during the follow-up period: 13/67 (19.4%) in the group treated with domperidone and 17/44 (38.6%) in the placebo-treated group (P = 0.03). Low-seropositive dogs treated with domperidone (4/40, 9.1%) were significantly less likely to develop disease compared to low-seropositive dogs treated with placebo (7/24, 29.2%; P = 0.04), while no differences were found between domperidone (9/23, 39.1%) and placebo (10/20, 50%) in medium- to high-seropositive dogs. At the end of the study, a higher proportion of Leishmania PCR-positive dogs was observed in the placebo-treated group (16/33, 48.5%) compared to the domperidone group (13/51, 25.5%; P = 0.04). Furthermore, low-seropositive dogs treated with domperidone with an increase of IFN-γ concentration presented a higher increase than those treated with placebo at the end of the study. Four dogs treated with domperidone presented self-limiting diarrhea. CONCLUSIONS: Healthy dogs with low L. infantum antibody levels treated with domperidone were less likely to develop disease compared to placebo-treated dogs. Furthermore, domperidone presented a good safety profile.

First identification of Strongyloides stercoralis infection in a pet dog in Argentina, using integrated diagnostic approaches.

BACKGROUND: Strongyloides stercoralis is a soil-transmitted intestinal nematode with a complex life cycle that primarily affects humans, non-human primates, dogs, and occasionally cats. This study presents, to the best of our knowledge, the first case of S. stercoralis infection and its genotyping in a domestic dog from Argentina. METHODS: The patient was a female wired-haired Teckel dog exhibiting recurrent coughing. Coproparasitological analysis using the Baermann technique revealed the presence of rhabditiform larvae morphologically compatible with S. stercoralis. To confirm this finding, molecular diagnosis (18S ribosomal RNA) and analysis of the cox1 gene were performed. RESULTS: We identified a haplotype (HP20) that has previously only been related to S. stercoralis infection in dogs, but was found in the present study to be highly related to the haplotype (HP16) of a zoonotic variant and divergent from those previously described from human patients in Argentina. Furthermore, unlike in human cases following treatment with ivermectin, the dog was negative after moxidectin treatment according to polymerase chain reaction of the sampled faeces. CONCLUSIONS: This case report shows the importance of further investigation into potential transmission events and prevalences of S. stercoralis in dogs and humans in South America. The results reported here should also encourage future work that examines different scenarios of infection with S. stercoralis in dogs and humans with the aim of integrating clinical management, diagnosis, treatment and follow-up strategies in the quest for new approaches for the treatment of this disease in animals and humans. The findings support the adoption of a One Health approach, which recognizes the interconnectedness between animal and human health, in addressing parasitic infections such as strongyloidiasis.

A comparative study of eight serological methods shows that spike protein-based ELISAs are the most accurate tests for serodiagnosing SARS-CoV-2 infections in cats and dogs.

Introduction: Coronavirus disease 2019 (COVID-19) is an infectious zoonotic disease caused by SARS-CoV-2. Monitoring the infection in pets is recommended for human disease surveillance, prevention, and control since the virus can spread from people to animals during close contact. Several diagnostic tests have been adapted from humans to animals, but limited data on the validation process are available. Methods: Herein, the first comparative study of six "in house" and two commercial serological tests developed to monitor SARS-CoV-2 infection in pets was performed with a well-coded panel of sera (61 cat sera and 74 dog sera) with a conservative criterion (viral seroneutralisation and/or RT-qPCR results) as a reference. Four "in house" tests based on either the RBD fragment of the spike protein (RBD-S) or the N-terminal fragment of the nucleoprotein (N) were developed for the first time. The analytical specificity (ASp) of those tests that showed the best diagnostic performance was assessed. The validation included the analysis of a panel of sera obtained pre-pandemic from cats and dogs infected with other coronaviruses to determine the analytical Sp (17 cat sera and 41 dog sera). Results and discussion: ELISAS based on the S protein are recommended in serosurveillance studies for cats (RBD-S SALUVET ELISA, ELISA COVID UNIZAR and INgezim® COVID 19 S VET) and dogs (INgezim® COVID 19 S VET and RBD-S SALUVET ELISA). These tests showed higher diagnostic sensitivity (Se) and DSp in cats (>90%) than in dogs. When sera obtained prior to the pandemic and from animals infected with other coronaviruses were analyzed by RBD-S and N SALUVET ELISAs and INgezim® COVID 19 S VET, a few cross reactors or no cross reactions were detected when dog and cat sera were analyzed by tests based on the S protein, respectively. In contrast, the number of cross reactions increased when the test was based on the N protein. Thus, the use of tests based on the N protein was discarded for serodiagnosis purposes. The results obtained revealed the most accurate serological tests for each species. Further studies should attempt to improve the diagnostic performance of serological tests developed for dogs.

Dermacentor reticulatus - a tick on its way from glacial refugia to a panmictic Eurasian population.

The ornate dog tick (Dermacentor reticulatus) shows a recently expanding geographic distribution. Knowledge on its intraspecific variability, population structure, rate of genetic diversity and divergence, including its evolution and geographic distribution, is crucial to understand its dispersal capacity. All such information would help to evaluate the potential risk of future spread of associated pathogens of medical and veterinary concern. A set of 865 D. reticulatus ticks was collected from 65 localities across 21 countries, from Portugal in the west to Kazakhstan and southern Russia in the east. Cluster analyses of 16 microsatellite loci were combined with nuclear (ITS2, 18S) and mitochondrial (12S, 16S, COI) sequence data to uncover the ticks' population structures and geographical patterns. Approximate Bayesian computation was applied to model evolutionary relationships among the found clusters. Low variability and a weak phylogenetic signal showing an east-west cline were detected both for mitochondrial and nuclear sequence markers. Microsatellite analyses revealed three genetic clusters, where the eastern and western cluster gradient was supplemented by a third, northern cluster. Alternative scenarios could explain such a tripartite population structure by independent formation of clusters in separate refugia, limited gene flow connected with isolation by distance causing a "bipolar pattern", and the northern cluster deriving from admixture between the eastern and western populations. The best supported demographic scenario of this tick species indicates that the northern cluster derived from admixture between the eastern and western populations 441 (median) to 224 (mode) generations ago, suggesting a possible link with the end of the Little Ice Age in Europe.