Onchocerca Lupi Research Articles

A canine onchocercosis report from the portuguese west region in 2024: implications for Public Health

Abstract Issue/problem Onchocerca lupi parasitosis, known as onchocercosis, affects dogs, sporadically cats and humans, posing a public health concern due to possible vectors in the environment. This neglected tropical disease(NTD), has no known human cases outside endemic areas. However, recent reports in non-endemic areas raise concerns about future implications. Climate change has increased the potential risk of disease vectors establishing themselves in previously unaffected areas. Description of the problem A case of canine onchocercosis in the West Region of Portugal, made the pet owner look for medical counselling. Primary health care providers contacted the Public Health Unit(PHU) for guidance and actions. There had been no previous reports in this region. In this case report, we explore the potential public health implications, through a one-health approach. Results History of the disease was collected, and travel history of the dog revealed that he had lived in the Algarve during 11 years with only a one-and-a-half-month travel to Italy in this period. Literature review revealed reports of previous cases of oncochercosis in the Iberian Peninsula. Collaboration between the PHU, research institutes, and veterinary authorities led to the assumption of probable transmission in the Algarve. Lessons Increased vector surveillance is needed, especially in areas associated with animal onchocercosis. Proactive measures reduce transmission risks, protecting both humans and animals. Tracking animal cases is vital for understanding regional environmental factors. PHU’s must conduct thorough risk evaluations and maintain assertive risk communication strategies to address public and pet owner concerns effectively. Adopting a One Health approach improves the understanding of the disease dynamics and enables targeted interventions. Key messages • NTD’s transmitted by vectors pose a potential future challenge. This report underscores the need for a One Health approach, with collaborative multidisciplinary efforts to address these challenges. • Furthermore, systematic interaction and reporting between human, animal, and environmental health authorities are crucial to ensure comprehensive surveillance and mitigation strategies.

Beyond Tradition: Exploring Cutting-Edge Approaches for Accurate Diagnosis of Human Filariasis.

Filariasis is recognised as a global public health threat, particularly in tropical and subtropical regions. It is caused by infection with a nematode parasite of the superfamily Filarioidea, including Wuchereria bancrofti, Brugia malayi, Onchocerca volvulus, and Onchocerca lupi. Three main types of filariasis have been classified: lymphatic filariasis, subcutaneous filariasis, and serous cavity filariasis. The symptoms exhibited by individuals afflicted with filariasis are diverse and contingent upon several variables, including the species of parasite, the host's health and immune response, and the stage of infection. While many classical parasitological techniques are considered indispensable tools for the diagnosis of parasitic infections in humans, alternative methods are being sought due to their limitations. Novel tests based on host-parasite interactions offer a rapid, simple, sensitive, and specific diagnostic tool in comparison to traditional parasitological methods. This article presents methods developed in the 21st century for the diagnosis of filariasis caused by invasion from W. bancrofti, B. malayi, O. volvulus, and O. lupi, as well as techniques that are currently in use. The development of modern diagnostic methods based on molecular biology constitutes a significant advancement in the fight against filariasis.

Filarial Nematodes in Dogs from the Northeast Region of Brazil.

Medical and veterinary filarial nematodes are transmitted by blood-feeding vectors. In dogs, these parasites are mainly represented by nematodes in which microfilariae dwell in the blood (Dirofilaria spp. and Acanthocheilonema spp.) or skin (Cercopithifilaria spp. and Onchocerca lupi). The aim of this study was to determine the prevalence of these filarial infections in dogs residing in a touristic, heavily populated location in the northeastern region of Brazil. Blood samples (n = 245) were assessed by a modified Knott test, followed by a qualitative ELISA test (SNAP® 4Dx® Plus, IDEXX Laboratory, Westbrook, Maine, USA) for the detection of antibodies against Anaplasma spp., Borrelia burgdorferi sensu lato, Ehrlichia spp. and antigens of Dirofilaria immitis. Skin samples (n = 71) were microscopically examined and molecularly assessed through a PCR targeting the 12S rRNA gene. Microfilariae and antigen of D. immitis were detected simultaneously in 15 (6.1%; 95% CI = 3.7-9.8) animals. Nine animals (3.6%; 95% CI = 1.9-6.8) were D. immitis antigen positive but microfilariae negative and nine other animals (3.6%; 95% CI = 1.9-6.8) were microfilariae positive but D. immitis antigen negative. D. immitis positive dogs were found in four different municipalities. No filarioids were detected in the skin after microscopical and molecular analyses. Data from this study demonstrate that D. immitis is the main filarial nematode infecting dogs in coastal areas in northeastern Brazil. Based on the potential risk of infection in which animals are submitted, it is essential to perform tests to detect microfilariae and D. immitis antigen. Preventive measures must be adopted by using microfilaricidal compounds and anti-feeding insecticides to prevent canine infection.

Development of an indirect ELISA for the serodiagnosis of canine infection by Onchocercalupi

Onchocercalupi is a zoonotic filarioid parasite of dogs and cats with widespread distribution. A specific non-invasive diagnostic assay for the detection of O.lupi infections remains unavailable. This study aimed to assess the accuracy, specificity, and sensitivity of an ELISA test designed using nine peptides from two O.lupi proteins. Sera (n = 54) collected from O.lupi infected dogs from endemic areas (Portugal and USA), alongside sera from dogs positive for Dirofilariaimmitis, D.repens, Cercopithifilariabainae, and Acanthocheilonemareconditum (n = 53) from a non-endemic area for O.lupi, as well as from helminth-free dogs (n = 60), were tested. The checkerboard titration method was applied for the optimization of peptide concentrations and conjugate anti-dog dilutions. Sensitivity, specificity, and optimal cut-off values were calculated using ROC curve analysis. All peptides reacted against sera of O.lupi, with no correlation between optic density (OD) values and microfilariae (mfs) loads. Sensitivity and specificity values ranging from 85.45 to 100%, and 88.89% to 100%, respectively, were recorded for all peptides examined, with 100% specificity and sensitivity observed for peptides 40_3, 40_5, 130_3, 120_3 and 40_1, 130_5, respectively. The maximum cut-off value was observed for peptides 40_5 (0.765) and 40_3 (0.708). Testing of sera from dogs positive for other filarioids resulted in lower OD values (up to 1.565) for peptides 40_3 and 40_5 when compared with O.lupi (up to 2.929). The availability of this assay will be of value in epidemiological studies of canine O.lupi infection in both endemic and non-endemic areas, and in assessing the risk for zoonotic transmission.

Biting midges (Diptera: Ceratopogonidae) as putative vectors of zoonotic Onchocerca lupi (Nematoda: Onchocercidae) in northern Arizona and New Mexico, southwestern United States.

Onchocerca lupi (Rodonaja, 1967) is an understudied, vector-borne, filarioid nematode that causes ocular onchocercosis in dogs, cats, coyotes, wolves, and is also capable of infecting humans. Onchocercosis in dogs has been reported with increasing incidence worldwide. However, despite the growing number of reports describing canine O. lupi cases as well as zoonotic infections globally, the disease prevalence in endemic areas and vector species of this parasite remains largely unknown. Here, our study aimed to identify the occurrence of O. lupi infected dogs in northern Arizona, New Mexico, and Utah, United States and identify the vector of this nematode. A total of 532 skin samples from randomly selected companion animals with known geographic locations within the Navajo Reservation were collected and molecularly surveyed by PCR for the presence of O. lupi DNA (September 2019-June 2022) using previously published nematode primers (COI) and DNA sequencing. O. lupi DNA was detected in 50 (9.4%) sampled animals throughout the reservation. Using positive animal samples to target geographic locations, pointed hematophagous insect trapping was performed to identify potential O. lupi vectors. Out of 1,922 insects screened, 38 individual insects and 19 insect pools tested positive for the presence of O. lupi, all of which belong to the Diptera family. This increased surveillance of definitive host and biological vector/intermediate host is the first large scale prevalence study of O. lupi in companion animals in an endemic area of the United States, and identified an overall prevalence of 9.4% in companion animals as well as multiple likely biological vector and putative vector species in the southwestern United States. Furthermore, the identification of these putative vectors in close proximity to human populations coupled with multiple, local zoonotic cases highlight the One Health importance of O. lupi.

Autochthonous Onchocerca lupi infection of a domestic dog in Austria

Onchocerca lupi is an emerging canine ocular pathogen with zoonotic potential. In Europe, known endemic areas are the Iberian Peninsula and Greece, but the parasite has also been found in Romania, Hungary, and Germany. A 5-year-old Irish Wolfhound was presented in August 2021 with ocular discharge. A subconjunctival granulomatous nodule containing several nematode fragments was removed. Molecular analysis of the mitochondrial cytochrome c oxidase subunit I gene confirmed the presence of O. lupi genotype 1. This is the first report of autochthonous O. lupi infection in a dog from Austria.Graphical

Immunoselective progression of a multi-epitope-based subunit vaccine candidate to convey protection against the parasite Onchocercalupi

Globalization has resulted in an increasing worldwide movement of humans and animals as well as changes in the external environment, temperature, and social interactions, resulting in the accelerated emergence of new diseases in humans and dogs, such as Onchocerca lupi-caused ocular onchocerciasis. Presently, zoonotic onchocerciasis affects 15.5 million people globally; however, the lack of effective anthelmintics and vaccinations highlighted the disease as a global public health concern. Therefore, the current study offers computational methods for anticipating and creating a multi-epitope subunit vaccine targeting Onchocerca lupi by utilizing suitable linkers and adjuvants to combine CTL, HTL, and BCL epitopes. Three different vaccines (V1, V2, and V3) were designed using three distinct adjuvants and then the vaccine constructs antigenicity, solubility, and non-allergenicity were determined. Then, the physicochemical characteristics of the constructed vaccine candidates were analyzed, and also the tertiary structure of the vaccines was anticipated, which was later verified and refined. Molecular docking and molecular dynamics simulation results showed that the V1 vaccine constructs expected affinity and binding free energy for the dimeric state of human Toll-like receptor-4 (hTLR-4) were promising. These results indicate that the suggested vaccine candidate could probably enhance the immune response to Onchocerca lupi infection. The results should be confirmed in experimental studies.

LupiQuant: A real-time PCR based assay for determining host-to-parasite DNA ratios of Onchocerca lupi and host Canis lupus from onchocercosis samples.

Onchocerca lupi is a filarial nematode that causes ocular onchocercosis in canines globally including North America and areas of Europe, North Africa, and the Middle East. Reported incidence of this parasite in canines has continued to steadily escalate since the early 21st century and was more recently documented in humans. Whole genome sequencing (WGS) of this parasite can provide insight into gene content, provide novel surveillance targets, and elucidate the origin and range expansion. However, past attempts of whole genome sequencing of other Onchocerca species reported a substantial portion of their data unusable due to the variable over-abundance of host DNA in samples. Here, we have developed a method to determine the host-to-parasite DNA ratio using a quantitative PCR (qPCR) approach that relies on two standard plasmids each of which contains a single copy gene specific to the parasite genus Onchocerca (major body wall myosin gene, myosin) or a single copy gene specific to the canine host (polycystin-1 precursor, pkd1). These plasmid standards were used to determine the copy number of the myosin and pkd1 genes within a sample to calculate the ratio of parasite and host DNA. Furthermore, whole genome sequence (WGS) data for three O. lupi isolates were consistent with our host-to-parasite DNA ratio results. Our study demonstrates, despite unified DNA extraction methods, variable quantities of host DNA within any one sample which will likely affect downstream WGS applications. Our quantification assay of host-to-parasite genome copy number provides a robust and accurate method of assessing canine host DNA load in an O. lupi specimen that will allow informed sample selection for WGS. This study has also provided the first whole genome draft sequence for this species. This approach is also useful for future focused WGS studies of other parasites.

Feline ocular onchocercosis by Onchocerca lupi: Phylogenetic insights and implication for veterinary health

Onchocerca lupi is a vector-borne filaroid which affects wild (i.e., wolves, coyotes) and domestic carnivores (i.e., dogs, cats), and occasionally humans. This nematode causes ocular damage due to the location of adult worms embedded in the eye connective tissues. Several human cases of onchocercosis by O. lupi have been reported in Europe, Asia, north Africa, and the USA where the infection thrives in dogs and less frequently in cats. In this study, we review clinical aspects of feline infestation by O. lupi, and report the first case of this onchocercid in a cat from Romania, showing a subconjunctival mass located at the medial canthus of the right eye; worms were surgically removed from the ocular nodule and morphologically and molecularly identified. Lesions were examined and characterized using histological procedures. Nematodes were identified as O. lupi based on their morphology at the direct observation as well as at the histological examination. Molecular and phylogenetic analysis confirmed the identification of this onchocercid, with the cox 1 sequence obtained clustering with those available in public repositories, including isolates from dogs and cats from Europe and USA. Despite the few reports available on the occurrence of this parasite on domestic cats, these felines are regarded as potential hosts of O. lupi in Portugal and USA. Moreover, the spread of feline ocular onchocercosis in Eastern Europe countries draw attention on the need of additional studies to confirm the potential vectors involved in its transmission cycle.

Genetic and geographical delineation of zoonotic vector-borne helminths of canids

Several zoonotic vector-borne helminths (VBHs) infesting canids cause serious veterinary and medical diseases worldwide. Increasing the knowledge about their genetic structures is pivotal to identify them and therefore to settle effective surveillance and control measures. To overcome the limitation due to the heterogeneity of large DNA sequence-datasets used for their genetic characterization, available cytochrome c oxidase subunit 1 (cox1) (n = 546) and the 12S rRNA (n = 280) sequences were examined using combined bioinformatic approach (i.e., distance-clustering, maximum likelihood phylogeny and phylogenetic evolutionary placement). Out of the 826 DNA available sequences from GenBank, 94.7% were characterized at the haplotype level regardless sequence size, completeness and/or their position. A total of 89 different haplotypes were delineated either by cox1 (n = 35), 12S rRNA (n = 21) or by both genes (n = 33), for 14 VBHs (e.g., Acanthocheilonema reconditum, Brugia spp., Dirofilaria immitis, Dirofilaria repens, Onchocerca lupi and Thelazia spp.). Overall, the present approach could be useful for studying global genetic diversity and phylogeography of VBHs. However, as barcoding sequences were restricted to two mitochondrial loci (cox1 and 12S rRNA), the haplotype delineation proposed herein should be confirmed by the characterization of other nuclear loci also to overcome potential limitations caused by the heteroplasmy phenomenon within the mitogenome of VBHs.

Onchocerca lupi in imported dogs in the UK: implications for animal and public health

BackgroundOnchocerca lupi is a filarial nematode affecting dogs, and occasionally cats and humans, in continental Europe, North Africa, the Middle East, and the USA. Adult worms are usually found in periocular nodules and enucleation is sometimes required if the infection fails to respond to other treatment options.Case presentationHere, we report the presence of O. lupi in the UK for the first time. Of two dogs re-homed from continental Europe, one developed an ocular nodule seven years after arrival from Portugal. The conjunctival perilimbal mass in its left eye was surgically removed but despite anthelminthic treatment, a further nodule developed in the same eye six months later. In the second case - a dog imported from Romania 12 months earlier - a perilimbal mass was excised from the left eye and prior anthelminthic treatment was supplemented with oral prednisolone and doxycycline. However, nodules recurred, and the left globe was subsequently enucleated. Conjunctival hyperaemia then appeared in the right eye and neither additional anthelminthic treatment nor removal of worm masses failed to prevent the further development of lesions. Excised adult worms were identified in both cases as O. lupi based on morphological characteristics, as well as PCR and sequencing of cytochrome c oxidase subunit I and 12S rRNA gene fragments.ConclusionO. lupi parasitosis can apparently remain cryptic in dogs for several years before any clinical signs manifest. Moreover, the progression of infection can be highly aggressive and recalcitrant to both surgical intervention and anthelminthic treatment. Increasingly, former stray dogs of unknown infection status are entering the UK, raising both veterinary and public health concerns.

Dermal microfilariae of dogs, jackals and cats in different regions of Iran

BackgroundDue to the complexity of retrieving skin-dwelling microfilariae, filarioids of dogs presenting dermal microfilariae (e.g. Cercopithifilaria spp., Onchocerca lupi) are relatively unknown compared to Dirofilaria spp. and Acanthocheilonema spp. whose microfilariae circulate in the blood. Although Cercopithifilaria spp. and O. lupi filarioids are distributed worldwide, there is a paucity of information on their occurrence in Iran. The aim of this study was to investigate these filarioids in a large population of dogs from different regions of Iran.MethodsFrom October 2018 to September 2020, skin biopsies were obtained from dogs housed in shelters (n = 557) and privately owned dogs (n = 26) in seven provinces of Iran (Hamedan, Kermanshah, Yazd, Mazandaran, Khuzestan, Lorestan, Esfahan), as well as from three road-killed jackals (Canis aureus) and three cats (Felis catus) in Hamedan province. The skin biopsies were first soaked in saline solution at room temperature overnight, and examined for dermal microfilariae under the microscope. Positive skin specimens and sediments were tested by PCR for a 304-bp region of the mitochondrial cytochrome c oxidase subunit 1 (cox1) gene and amplicons were sequenced.ResultsMicrofilariae of Cercopithifilaria spp. were found in skin biopsies of 32 of the 583 (5.5%) dogs tested, with infection rates of up to 25% in Kermanshah. No microfilariae were recovered from skin biopsy samples collected from dogs in Khorramabad and Ahvaz, nor from the examined jackals and cats. None of the privately owned dogs were found to be infected. Morphologic and morphometric characteristics of the microfilariae were consistent with C. bainae. Eighteen skin samples were positive for the cox1 gene, of which 15 sequences showed a nucleotide identity of 100% and three of 93.4% with the reference sequence of C. bainae available in GenBank (haplotype I; GenBank accession number: JF461457).ConclusionsThe data from this study broadens current knowledge on the geographical distribution of C. bainae in dogs in Middle Eastern countries. Further studies on different wild canine species in the country (e.g. jackal, fox, wolf) could provide further information on the epidemiology of these filarioids. A particular focus should be put on zoonotic O. lupi given the reports of its presence in human patients from this country.Graphical

Confirmed cases of human Onchocerca lupi infection: a systematic review of an emerging threat.

Diverse Onchocerca species are present mostly parasitizing ungulates, with the exception of Onchocerca volvulus (O. volvulus) in humans and O. lupi in canids and cats. The human cases due to the O. lupi have been more highlighted during last years. So, the present review was performed to determine the detailed characteristics of confirmed human O. lupi case reports documented worldwide. Hence, a systematic search was done using English international databases (Scopus, PubMed, Web of Science, Embase, ProQuest, and Google Scholar). Totally, 14 confirmed human cases were documented during the last decade, mostly from the USA and Turkey with 7 and 3 cases, respectively. Most cases (7 individuals) were male with the age range of 22-month-old to 54-year-old. The parasite was frequently isolated from the right eye (5 cases), followed by the left eye (4 cases), cervical spinal canal (3 cases), scalp, and right forearm (one case each). Molecular identification of the isolated agent was the preferred way of diagnosis in most cases (9 records). In conclusion, human O. lupi cases have been more highlighted in recent years, whether due to the improved diagnostics and/or host-switching phenomenon, and both veterinarians and healthcare authorities should be alerted.

Complete mitochondrial genome of Onchocerca lupi (Nematoda, Onchocercidae)

Onchocerca lupi, Rodonaja 1967, is an emerging, zoonotic filarial nematode parasite that causes ocular disease in dogs, cats, wild canids, and humans. It is the causative agent of ocular onchocercosis in canines with increasing incidence in both North America and the Old World during the early twenty-first century. We report the complete mitochondrial genome of an O. lupi isolate from a dog from Arizona, southwestern USA, and its genetic differentiation from related Onchocerca species. The whole mitochondrial genome was obtained from whole genome sequencing of genomic DNA isolated from an adult worm. This mitogenome is 13,766 bp in size and contains 36 genes and a control region. This mitogenome provides a valuable resource for future studies involving epidemiological surveillance, population genetics, phylogeography, and comparative mitogenomics of this emerging pathogen and other parasitic nematodes.

Molecular detection of zoonotic filarioids in Culex spp. from Portugal.

To investigate the role of dipterans in the transmission of Onchocerca lupi and other zoonotic filarioids, samples were collected from different sites in Algarve, southern Portugal, morphologically identified and molecularly tested for filarioids. Culex sp. (72.8%) represented the predominant genus followed by Culicoides sp. (11.8%), Ochlerotatus sp. (9.7%), Culiseta sp. (4.5%), Aedes sp. (0.9%) and Anopheles sp. (0.3%). Nineteen (2.8%) specimens scored positive for filarioids, with Culex pipiens quinquefasciatus (2%) positive for Dirofilaria immitis (1.4%), Dirofilaria repens, Acanthocheilonema reconditum, Onchocerca lupi, unidentified species of Filarioidea (0.2%, each) and Onchocercidae (0.6%). Additionally, Culiseta longiareolata (6.5%), Ochlerotatus caspius (3%) and Culex laticinctus (0.2%) scored positive for unidentified Onchocercidae, A. reconditum and for O. lupi, respectively. This is the first report of the occurrence of DNA of O. lupi, D. repens and A. reconditum in Culex spp. in Portugal. Information regarding the vectors and the pathogens they transmit may help to adopt proper prophylactic and control measures.

Canine ocular onchocerciasis in New Mexico: Risk factors for disease.

To determine whether dogs are at variable risk of developing canine ocular onchocerciasis based on coat color or size, factors that may influence feeding behavior of the putative vectors of Onchocerca lupi¸ the filarial nematode parasite causing this disease. One hundred twenty-five client-owned dogs diagnosed with confirmed or suspected onchocerciasis. 1255 dogs without signs of this disease were utilized for comparison. Dogs lacking signs of canine onchocerciasis were assessed for coat color and weight. Proportions of dogs with these characteristics were used to predict signalment in a group of dogs with this disease, if the investigated characteristics were unrelated to disease risk. Predicted values were compared statistically with observed values in the diseased dog population. Black fly color preference was assessed utilizing black, brown, and white traps and statistically assessing any differences in trapping based on trap color. Results suggest that large, black dogs are more likely to develop canine ocular onchocerciasis than was predicted by chance alone (p=0.012). Results for smaller dogs with other coat colors were not significant. An increased risk for black dogs was supported by trapping data, as black flies were trapped significantly more often in black traps (p<0.001). While factors other than size and color probably also influence the likelihood of O. lupi infection and disease development, our results may assist clinicians in their diagnosis of canine ocular onchocerciasis and provide them with a tool to help educate their clients as to their dogs' risk of developing this disease.

Major antigen and paramyosin proteins as candidate biomarkers for serodiagnosis of canine infection by zoonotic Onchocerca lupi.

Onchocerca lupi (Spirurida: Onchocercidae) is a filarial worm parasitizing domestic carnivores and humans. Adult nematodes usually localize beneath in the sclera or in the ocular retrobulbar of infected animals, whilst microfilariae are found in the skin. Therefore, diagnosis of O. lupi is achieved by microscopic and/or molecular detection of microfilariae from skin biopsy and/or surgical removal of adults from ocular tissues of infected hosts. An urgent non-invasive diagnostic tool for the diagnosis of O. lupi in dog is mandatory. In this study, an immunoproteomic analyses was performed using a combination of immunoblotting and mass spectrometry techniques. Onchocerca lupi major antigen (Ol-MJA) and paramyosin (Ol-PARA) proteins were identified as potential biomarkers for serodiagnosis. Linear epitopes were herein scanned for both proteins using high-density peptide microarray. Sera collected from dog infected with O. lupi and healthy animal controls led to the identification of 11 immunodominant antigenic peptides (n = 7 for Ol-MJA; n = 4 for Ol-PARA). These peptides were validated using sera of dogs uniquely infected with the most important filarioids infesting dogs either zoonotic (Dirofilaria repens, Dirofilaria immitis) or not (Acanthocheilonema reconditum and Cercopithifilaria bainae). Overall, six antigenic peptides, three for Ol-MJA and for Ol-PARA, respectively, were selected as potential antigens for the serological detection of canine O. lupi infection. The molecular and proteomic dataset herein reported should provide a useful resource for studies on O. lupi toward supporting the development of new interventions (drugs, vaccines and diagnostics) against canine onchocercosis.

Human Ocular Onchocerca lupi Infection Diagnosed in Norway

Introduction: Zoonotic Onchocerca lupi infection is a rare but emerging zoonotic disease affecting the eye, subcutaneous tissue and subdural cervical spine. Endemic areas of O. lupi are East and Central Europe, Turkey, Iran and the Northwest of the USA. Thirteen confirmed cases have been published in the world literature. Case Presentation: We present a case of subconjunctival O. lupi infection in the left eye of a Norwegian male. The infection was most likely imported from Turkey. The diagnosis was verified by direct microscopy and molecular analyses with polymerase chain reaction (PCR) with subsequent sequencing. The worm did not contain microfilaria and was surgically removed. The patient was treated with tapering doses of topical steroids. At 6 months follow-up, he was asymptomatic. Conclusion: Increasing numbers of O. lupi infections are reported and it is not clear whether the increasing number of infections is true or due to availability of novel diagnostic tools that correctly identify the cases. Humans cannot eliminate their exposure to vector-borne zoonotic diseases and increasing globalization increases the risk of infection. Both physicians and laboratory staff should be aware of the existence of zoonotic onchocerciasis in their countries.

Coyotes as Reservoirs for Onchocerca lupi, United States, 2015-2018.

The Onchocerca lupi nematode infects dogs, cats, and humans, but whether it can be spread by coyotes has been unknown. We conducted surveillance for O. lupi nematode infection in coyotes in the southwestern United States. We identified multiple coyote populations in Arizona and New Mexico as probable reservoirs for this species.

Molecular Approach for the Diagnosis of Blood and Skin Canine Filarioids.

The zoonotic Onchocerca lupi and tick-transmitted filarioids of the genus Cercopithifilaria remain less well known due to the difficulties in accessing to skin samples as target tissues. Here, we proposed a molecular approach reliying on multiplex qPCR assays that allow the rapid identification of filarioids from canine blood, skin, and tick samples. This includes two newly developed duplex qPCR tests, the first one targeting filarial and C. grassii DNA (CanFil-C. grassii). and the second qPCR assay designed for the detection of Cercopithifilaria bainae and Cercopithifilaria sp. II DNAs (C. bainae-C.spII). The third one is a triplex TaqMan cox 1 assay targeting DNA of blood microfilariae (e.g., Dirofilaria immitis, Dirofilaria repens and Acanthocheilonema reconditum). The novel duplex qPCRs developed were validated in silico and by screening of known DNA collection. The qPCR assays were also used for screening the blood and tick samples of 72 dogs from Algeria. This allowed the identification of canine filariasis infection with 100% of specificity and 89.47% and 100% of sensitivity from naturally infected blood and tick samples, respectively. The prevalences of 26.39% for D. immitis and 5.56% for both D. repens and A. reconditum were reported in blood and tick samples. Cercopithifilaria DNAs were detected only in tick samples, with a prevalence of 4.17% and 5.56% for C. bainae and Cercopithifilaria sp. II, respectively. Co-infections were diagnosed in 6.94% and 13.89% of blood and tick samples, respectively. Whereas all samples were negative for C. grassii DNA. The use of engorged ticks instead of blood and skin samples could be an easier option for the surveillance of all canine filarioids herein investigated. The multiplex qPCR assays herein validated were shown to be useful in the detection of filarial co-infections by overcoming sequencing of positive samples.