Paraparesis due to angio-neurotropic Gurltia paralysans in a domestic cat (Felis catus) and retrospective study on feline gurltiosis cases in South America.

Introduction: The nematode Gurltia paralysans is a neglected angio-neurotropic parasite causing chronic meningomyelitis in domestic cats (Felis catus) as well as wild felids of the genus Leopardus in South America. Adult G. paralysans nematodes parasitize the leptomeningeal veins of the subarachnoid space and/or meningeal veins of the spinal cord parenchyma. The geographic range of G. paralysans encompasses rural and peri-urban regions of Chile, Argentina, Uruguay, Colombia and Brazil. Methods: This case report presents clinical and pathological findings of a G. paralysans-infected cat suffering from severe thrombophlebitis and meningomyelitis resulting in ambulatory paraparesis. Neurological examination of affected cat localized the lesions at the thoracolumbar (T3-L3) and lumbosacral (L4-Cd4) segments. Molecular and morphological characteristics of extracted nematodes from parasitized spinal cord veins confirmed G. paralysans. Additionally, data obtained from a questionnaire answered by cat owners of 12 past feline gurltiosis cases (2014-2015) were here analyzed. Questionnaire collected data on age, gender, geographic location, type of food, hunting behavior, type of prey, and other epidemiological features of G. paralysans-infected cats. Results and Discussion: Data revealed that the majority of cats originated from rural settlements thereby showing outdoor life styles with hunting/predatory behaviors, being in close contact to wild life [i.e. gastropods, amphibians, reptiles, rodents, birds, and wild felids (Leopardus guinia)] and with minimal veterinary assistance. Overall, this neglected angio-neurotropic G. paralysans nematode still represents an important etiology of severe thrombophlebitis and meningomyelitis of domestic cats living in endemic rural areas with high biodiversity of definitive hosts (DH), intermediary (IH), and paratenic hosts (PH). The intention of this study is to generate awareness among veterinary surgeons as well as biologists on this neglected feline neuroparasitosis not only affecting domestic cats but also endangered wild felid species of the genus Leopardus within the South American continent.

Gurltia paralysans: A Neglected Angio-Neurotropic Parasite of Domestic Cats (Felis catus) and Free-Ranging Wild Felids (Leopardus spp.) in South America.

Gurltia paralysans is a neglected and re-emerging metastrongyloid angio-neurotropic nematode causing severe chronic meningomyelitis in domestic cats (Felis catus) as well as in free-ranging small wild felids such as kodkods (Leopardus guigna), margays (Leopardus wiedii) and the northern tiger cat (Leopardus triginus) in South America. Within these definitive hosts (DH), adult males and females of G. paralysans parasitize the leptomeningeal veins of the subarachnoid space and/or the meningeal veins of spinal cord parenchyma, inducing vascular alterations. Feline gurltiosis has been associated with progressive thrombophlebitis of the meningeal veins, resulting in ambulatory paraparesis, paraplegia, ataxia, hindlimb proprioceptive deficit, uni- or bilateral hyperactive patellar reflexes, faecal and urinary incontinence, and tail paralysis. The complete life cycle of G. paralysans has not been elucidated yet, but most probably involves gastropods as obligate intermediate hosts (IH). In terms of epidemiology, G. paralysans infections in domestic and wild felids are scattered around various South American countries, with hyperendemic areas in southern parts of Chile. Etiological diagnosis of G. paralysans still represents a challenge for clinicians due to a lack of evidence of the excretion of either eggs or larvae in faeces or in other body fluids. Diagnosis is based on clinical neurological signs, imaging findings through computed tomography (CT), myelography, magnetic resonance imaging (MRI), and post mortem examination. Nonetheless, novel diagnostic tools have been developed, including semi-nested PCR for detecting circulating G. paralysans DNA in the cerebrospinal fluid, serum and blood samples as well as in serological diagnostic kits detecting parasite-derived antigens, but these need validation for routine usage. The hypothetical life cycle of G. paralysans is addressed in this article, including the exogenous stages (i.e., eggs, and first- (L1), second- (L2) and third-stage (L3) larvae) and obligate gastropod IH and/or paratenic hosts (PH), and we propose possible anatomical migration routes of infective L3 that reach the leptomeningeal veins in vivo. Finally, the pro-inflammatory endothelium- and leukocyte-derived innate immune reactions of the host against G. paralysans, which most likely result in thrombophlebitis and meningomyelitis, are briefly touched on.

Histological and Immunohistochemical Characterization of Vascular Alterations in Meninges of Cats Infected with Gurltia paralysans.

Gurltia paralysans, a metastrongyloid nematode, parasitizes in meningeal vessels in the thoracolumbar spinal cord of cats in South America and causes progressive paraparesis. Recently, the first report outside of South America described gurltiosis in a cat in Spain. As this parasitic disease has so far been largely neglected, especially outside of South America, the aim of the present case study was to add knowledge to the histologic and immunohistochemical characterization of central nervous lesions. To this purpose, formalin-fixed and paraffin-embedded (FFPE) tissue samples from the spinal cord and brain of five cats affected by clinical signs caused by Gurltia paralysans and of three control cats without CNS lesions were histopathologically examined using hematoxylin and eosin stain (HE), Elastica van Gieson stain, as well as periodic acid-Schiff (PAS) reaction. Moreover, immuno- histochemistry for alpha smooth muscle actin and Factor VIII-related antigen were performed to characterize vascular lesions. Lesions were consistent with previous descriptions and were mainly located in the spinal cord and consisted of chronic suppurative or lymphoplasmahistiocytic meningi tis as well as suppurative vasculitis, congestion and varicosis of meningeal veins. In view of the recent detection of this parasite in Europe and the increasing inner-European transport of rescued domestic cats, veterinarians in Europe should be aware of the clinical and pathomorphological presentation of this disease.

The Neglected Angio-Neurotrophic Parasite Gurltia paralysans (Nematoda: Angiostrongylidae): Northernmost South American Distribution, Current Knowledge, and Future Perspectives.

Gurltia paralysans is a rare metastrongyloid nematode in South America that has begun to gain relevance in feline internal medicine as a differential diagnosis of progressive degenerative myelopathy disorders. The parasite life cycle has not been fully elucidated but probably involves invertebrate gastropod fauna as obligate intermediate hosts; thus, G. paralysans remaining an extremely neglected parasitosis. Feline gurltiosis intra vitam diagnosis is highly challenging due to lack of evidence in the excretion of G. paralysans eggs and larvae, neither in feces nor in other body secretions because environmental stages and the transmission route of the parasite remain unknown. Unfortunately, no experimental trials for the treatment of feline gurltiosis have been conducted to date. However, there are some reports of the successfully antiparasitic drugs used with different effectiveness and clinical improvement results in diagnosed cats. Further studies are needed to evaluate the parasite occurrence among domestic cats and the neotropical wild felid species distributed within Colombia in addition to the gastropod fauna that may harbor the developing larvae (L1-L3) stages of this underestimated parasite.

A Molecular Survey on Neglected Gurltia paralysans and Aelurostrongylus abstrusus Infections in Domestic Cats (Felis catus) from Southern Chile.

Gurltia paralysans and Aelurostrongylus abstrusus are neglected metastrongyloid nematode species which infect domestic and wild cats in South American countries and in Chile, but no epidemiological studies on concomitant infections have been conducted in Chile so far. The aim of this study was not only to evaluate the occurrence of concomitant infections, but also to identify epidemiological risk factors associated with of G. paralysans and A. abstrusus infections in urban domestic cats (Felis catus) from Southern Chile. Blood samples from clinically healthy domestic cats from three cities of Southern Chile-Temuco, Valdivia, and Puerto Montt-were analyzed by an experimental semi-nested PCR protocol. A total of 171 apparently healthy domestic cats in Temuco (n = 68), Valdivia (n = 50), and Puerto Montt (n = 53) were sampled and analyzed. A total of 93 domestic cats (54.4%) were positive for G. paralysans, and 34 (19.9%) were positive for A. abstrusus infections. From those animals, 34 (19.9%) were co-infected. Cats positive with G. paralysans were found in all three cities; 47.2% in Puerto Montt, 48% in Valdivia, and 64.7% in Temuco. Levels of infection for A. abstrusus in the population under study were 4% (Valdivia), 10% (Puerto Montt), and 32.4% (Temuco). The present large-scale epidemiological study confirmed the presence of these neglected nematodes in domestic cat populations in Southern Chile, and described the possible risk factors associated with feline gurltiosis and aelurostrongylosis.

Evaluation of terrestrial gastropods as possible intermediate hosts of Gurltia paralysans in southern Chile / Avaliação de gastrópodes terrestres como possíveis hospedeiros intermediários de Gurltia paralysans no sul do Chile

Abstract Gurltia paralysans is the causal agent of gurltiosis in domestic cats in South America. Although the life cycle of G. paralysans is unknown, it is thought that gastropods could act as intermediate hosts (IHs), as is the case for several nematodes in the Angiostrongylidae family. The aim of this study was to search for G. paralysans larvae in terrestrial gastropods and determine their role in the life cycle of this nematode species. Terrestrial gastropod samples (n=835) were collected in Punucapa, Valdivia, southern Chile, where cases of gurltiosis had been reported before. The samples included species from the families Arionidae, Limacidae, Helicidae and Milacidae. All gastropods were subjected to enzymatic digestion to isolate G. paralysans larvae. Ten percent of the gastropod samples were analyzed using seminested PCR targeting the 28S rRNA gene, while 2.6% were analyzed by histopathological examination. The results indicated the absence of G. paralysans when using any of the three methods. In conclusion, further studies are needed to evaluate specific species of aquatic or native gastropods acting as possible IHs (in this geographic location).

Resumo Gurltia paralysans é o agente etiológico da gurltiose em gatos domésticos na América do Sul. Embora o ciclo biologico de G. paralysans seja desconhecido, provavelmente é indireto com gastrópodes atuando como hospedeiros intermediários (HIs), como no caso de vários nematoides da família Angiostrongylidae. O objetivo deste estudo foi investigar a presença de larvas de G. paralysans em gastrópodes terrestres para avaliar seu papel no ciclo de vida do parasito. Amostras de gastrópodes terrestres (n = 835) foram coletadas em Punucapa, Valdivia, sul do Chile, onde casos de gurltiose foram relatados anteriormente. As amostras incluíram espécies das famílias Arionidae, Limacidae, Helicidae e Milacidae. Todos os gastrópodes foram submetidos à digestão enzimática para isolar as larvas de G. paralysans. 10% das amostras foram analisadas, utilizando-se seminested PCR para o gen 28S RNAr de G. paralysans, enquanto 2,6% foram analisados ​​por exame histopatológico. Os resultados indicaram ausência de G. paralysans em todos os três métodos. Os dados permitem concluir que são necessários mais estudos para avaliar espécies específicas de gastrópodes aquáticos ou nativos, que atuam como possíveis hospedeiros intermediários nessa localização geográfica.

Intra Vitam Diagnosis of Neglected Gurltia paralysans Infections in Domestic Cats (Felis catus) by a Commercial Serology Test for Canine Angiostrongylosis and Insights into Clinical and Histopathological Findings-Four-Case Report.

Gurltia paralysans is a metastrongyloid nematode which belongs to the Angiostrongylidae family and presents tropism for veins of the subarachnoid space in vivo of domestic and wild felids causing a progressive and chronic clinical manifestation of paraparesis/paraplegia. The geographic distribution of G. paralysans includes rural and periurban areas of South America and was recently reported in Europe. To date, a definitive diagnosis of feline gurltiosis is still conducted by post-mortem examination of the spinal cord in affected animals. A presumptive diagnosis of feline gurltiosis can also be achieved based on data of compatible clinical signs and associated epidemiological risk factors. The aim of this preliminary study was to evaluate the commercial serological test Angio Detect TM® (IDEXX Laboratories) as a possible diagnostic method of feline gurltiosis in vivo. For the study, 10 domestic felines (Felis catus) which originated from a high endemic area of Southern Chile, were analyzed. All felines presented chronic paraparesis or severe paraplegia. Subsequently, commercial Angio Detect TM® serological tests for the detection of closely related Angiostrongylus vasorum in canids were performed according to manufacturer's instructions. Conducted serological tests were positive in seven of ten felines showing paraplegia/paraparesis and presumably infected with G. paralysans, and four of them were additionally necropsied, and presented macroscopic findings compatible with feline gurltiosis. Furthermore, the presence of adult female and male G. paralysans specimens at the level of the subarachnoid vasculature in affected spinal cord segments were observed during necropsy. Histopathology demonstrated severe eosinophilic meningomyelitis, coagulopathies with thrombosis in G. paralysans-parasitized leptomeningeal veins. Results of this preliminary study suggest a cross-reaction between A. vasorum-specific antigens, which also parasitize blood vessels in vivo, and G. paralysans when using an Angio Detect TM® test, which suggests its helpful use as a new diagnostic method for feline gurltiosis in live domestic felines. Additional specific antigen research will be required in order to better understand the sensitivity and specificity of A. vasorum antigens used in this test and for existing cross-reactivity with G. paralysans-derived antigens for future a suitable intra vitam immunodiagnosis of neglected feline gurltiosis.

Molecular Detection of Gurltia paralysans by Semi-Nested PCR in Cerebrospinal Fluid and Serum Samples from Domestic Cats (Felis catus).

Gurltia paralysans is an angio-neurotropic metastrongyloid nematode that infects domestic and wild cats, invading the veins of the subarachnoid space of the spinal cord and mainly causing progressive paralysis of the pelvic limbs. The definitive diagnosis of feline gurltiosis can only be achieved by post-mortem examination that reveals the presence of the nematode in the spinal cord vein vasculature. An early diagnosis with conclusive results is required since laboratory and imaging findings are not sufficient. Therefore, the purpose of this study was to detect the presence of G. paralysans, via semi-nested PCR, in samples of cerebrospinal fluid (CSF) and the sera of domestic cats naturally infected with the parasite. A total of 12 cats with a diagnosis suggestive of feline gurltiosis were selected, and they underwent a complete neurological and imaging examination. DNA samples were analysed by semi-nested PCR, with universal (AaGp28Sa1/AaGp28Ss1) and specific (Gp28Sa3/Aa28Ss2) primers, for G. paralysans (G. paralysans 18S rRNA gene, partial sequence; ITS 1, 5.8S rRNA gene, and ITS 2, complete sequence; and 28S rRNA gene, partial sequence) and Aelurostrongylus abstrusus, obtaining amplifications of 356 and 300 bp, which indicated the presence or absence of nematode DNA, respectively. The presence of G. paralysans was detected in the CSF of four out of nine cats, and the sera of seven out of seven cats. In the sera analysis of five out of seven cats, a mixed infection with A. abstrusus was found, despite no alterations of the respiratory tract being observed during the necropsies. It is proposed that serum samples could be more effective than CSF in detecting the parasite by PCR analysis. Sequencing analysis showed high percentages of identity with G. paralysans, which indicated the feasibility of detection and the sensitivity/specificity of the method used, suggesting the implementation of semi-nested PCR as a routine diagnostic test for early and timely detection of feline gurltiosis.

First case report of nematode parasitic myelopathy in a wild feline in Brazil / Primeiro relato de caso de mielopatia parasitária causada por nematódeo em um felídeo selvagem no Brasil

Abstract Parasitic myelopathy caused by Gurltia paralysans in domestic cats is a disease commonly reported in several South American countries. The adult parasite is lodged in the meningeal veins and spinal cord, often causing clinical manifestations of vascular proliferation, thrombophlebitis, and medullary compression. Wild felines are believed to be the definitive hosts of this parasite. The infection occurs through the ingestion of paratenic hosts, but the life cycle of G. paralysans is not yet clearly understood. In this paper, we discuss a case of parasitic myelopathy in a margay (Leopardus wiedii) that died during post-surgical care. Necropsy revealed focal hemorrhages in the thoracolumbar spinal cord. A microscopic examination revealed adult nematodes and eggs inside the veins of subarachnoid space in spinal cord, suggesting G. paralysans infection. This is first description of parasitic myelopathy in a margay in Brazil.

Resumo Mielopatia parasitária causada por Gurltia paralysans em gatos domésticos é uma doença comumente relatada em vários países da América do Sul. O parasita adulto aloja-se nas veias das meninges e da medula espinhal, muitas vezes causando proliferação vascular, tromboflebite e compressão medular, que se manifestam como sinais clínicos. Acredita-se que os felídeos selvagens sejam hospedeiros definitivos deste parasita e que a infecção ocorre por ingestão de hospedeiros paratênicos, entretanto seu ciclo de vida completo é desconhecido. Aqui, apresentamos um caso de um gato-maracajá (Leopardus wiedii) que morreu durante a assistência pós-cirúrgica. Na necropsia, foram observadas hemorragias focais na medula espinhal toracolombar. A microscopia revelou presença de nematódeos adultos e ovos, localizados dentro das veias do espaço subaracnoide da medula espinhal, o que sugeriu a infecção por G. paralysans. Esta é a primeira descrição de mielopatia parasitária em um gato-maracajá no Brasil.

First ocular report of Gurltia paralysans (Wolffhügel, 1933) in cat.

A two-year-old cat from Tenerife, Canary Islands (Spain), presented with two months history of uveitis in the left eye. It had been treated for two months but still showed an active uveitis. After new treatment, eye examination showed a mobile worm in the anterior chamber. Following surgical removal, the worm was obtained. Morphological study revealed that it was a male metastrongyloid nematode (Nematoda: Metastrongyloidea) with caudal bursa and two similar spicules. Molecular tools based on the 18Sr RNA gene sequence identified the parasite as Gurltia paralysans, which is a neurotropic nematode previously found in South America. Therefore, this article describes the first report of ophthalmic case of parasitism by G. paralysans, and cites for first time this species out of South America.

Redescription and first molecular characterization of the little known feline neurotropic nematode Gurltia paralysans (Nematoda: Metastrongyloidea).

Gurltia paralysans is a poorly documented metastrongyloid nematode of cats, which mainly parasitizes the veins in the spinal cord subarachnoid space and parenchyma. Parasitic paraparesis caused by G. paralysans is a lesser-known spinal cord disease affecting domestic and wild felids of South America. Regions where feline gurltiosis is endemic include the southern parts of Chile and Argentina. Intra vitam diagnosis of feline gurltiosis remains challenging and is based primarily on neurological signs and the exclusion of other ethiologies for feline myelopathies. In view of the lack of information in the literature for this neglected feline neurological parasitosis, we have undertaken a detailed redescription and molecular characterization to expand on the previously available details in the original descriptions by Wolffhügel in 1993. The specimens used in this study were collected from spinal cord lesions of gurltiosis-affected domestic cats. Female and male specimens were morphologically and morphometrically examined using light and scanning electron microscopy. Molecular characterization was performed by sequencing a partial region of the nuclear ribosomal DNA and cytochrome oxidase gene of this parasite, and phylogenetic trees were constructed from the 28S D2-D3 and ITS2 regions using the Maximum Likelihood method. Sequence matching and phylogenetic analysis with these new sequences were consistent with the morphological classification of G. paralysans being within the Metastrongyloidea superfamily, but no consistent relation to a specific metastrongyloid family. The newly developed G. paralysans-specific PCR described here not only provides a useful diagnostic tool for feline gurltiosis in domestic cats living in endemic areas, but could also be used in large-scale epidemiological surveys on the intermediate mollusk host and the final host. By combining the morphology, molecular, and phylogenetic data we have reliably identified G. paralysans and confirmed its taxonomic status within the Metastrongyloidea.

Aspectos epidemiológicos, clínicos e anatomopatológicos da infecção por Gurltia paralysans em gatos / Epidemiological, clinical and pathological aspects of Gurltia paralysans infection in cats

Nos últimos 20 anos, uma doença neurológica desconhecida acometeu populações de gatos da Região da Campanha do RS e tornou-se um desafio diagnóstico para os veterinários locais. Os gatos afetados desenvolviam inicialmente paralisia da cauda, seguida de paraparesia progressiva nos membros pélvicos, alteração da marcha, posição plantígrada e ataxia proprioceptiva. Após longos períodos de evolução clínica (12-24 meses), quando se tornavam marcadamente paraparéticos e começavam a apresentar escaras de decúbito, eram sacrificados pelos proprietários. Na necropsia, demonstravam graus variados de atrofia dos músculos pélvicos e algum grau de avermelhamento das meninges entre T10 e L7, devido à presença de miríades de pequenos vasos sanguíneos, uma típica lesão varicosa, semelhante a um hamartoma vascular. Histologicamente, tais lesões consistiam de distensão do espaço subaracnóideo por vasos sanguíneos dilatados e tortuosos, repletos de sangue e, ocasionalmente, de trombos, que ocluíam parcial ou totalmente seus lúmens. Essas varizes venulares eram aleatoriamente circundadas por infiltrado inflamatório granulomatoso ou linfocítico com pequenos focos de eosinófilos maduros. No lúmen das vênulas varicosas havia secções transversais e longitudinais de parasitos. Com base na morfologia desses parasitos, em sua localização anatômica (vasos sanguíneos meníngeos) e na espécie afetada (gato), o nematódeo foi identificado como Gurltia paralysans. O objetivo desse trabalho é apresentar em detalhes os aspectos epidemiológicos, clínicos e anatomopatológicos dessa intrigante mielopatia de gatos e estabelecer definitivamente seu diagnóstico definitivo: paraplegia crural parasitária felina, uma doença descoberta no Chile, na década de 1930, e agora, pela primeira vez, descrita no Brasil.

In the last 20 years, an unknown neurological disease affected cat populations in the Western Border Region of the State of Rio Grande do Sul, Brazil. The onset of the disease was characterized by tail paralysis, followed by progressive paraparesis in the pelvic limbs, difficulty in ambulation and proprioceptive ataxia. After long prolonged clinical courses (12-24 months), when then affected cats became severely paraparetic and start to develop pressure sores do to decubitus, they were destroyed by the owners. At necropsy there were variable degrees of skeletal muscle atrophy of the pelvic muscles and some degree of reddening of the meninges at the level of T10-L7, due to the presence of a myriad of small blood vessels, as a typical varicose lesion that resembled a vascular hamartoma. Histologically, such lesions consisted of distension of the subarachnoid space due to a collection of dilated, blood-filled, tortuous blood vessels the lumina of which were occasionally partially or completely occluded by thrombi. Those varices were randomly surrounded by a lymphocytic or granulomatous inflammatory infiltrate with small foci of mature eosinophils. In the lumina of these varicose venules cross and longitudinal sections of nematode parasites could be observed. Based on the morphology of these parasites, in their anatomical localization (meningeal blood vessels) and in the species (cat) affected the nematode was identified as Gurltia paralysans. This paper describes detailed aspects of the epidemiology, clinical disease and pathology of this intriguing feline myelopathy and the definitive diagnosis of the condition: Feline crural parasitic paraplegia, a disease first described in Chile in the 1930's and now, for the first time, in Brazil.

Parasite meningomyelitis in cats in Uruguay / Meningomielites parasitária em gatos no Uruguai

Two outbreaks of progressive hind limb paresis in cats (Felis catus) caused by parasitic meningomyelitis in Uruguay are reported. The case studies occurred in 2008 and 2009 respectively, in the rural areas of Fray Bentos (33º 07' 40.39" S) and were characterized by hindquarter paralysis. This paralysis was progressive and had a chronic progression of approximately 12 months until the death or euthanasia of the animals. Clinical symptoms started with ataxia of the hindquarters with lateral side-to-side swaying and culminated in total paralysis. Two animals were sent for necropsy in 2009. The main histopathological findings were severe myelitis in the lumbar spinal cord with perivascular cuffing and white matter necrosis, severe nonsuppurative meningitis with thrombi in subarachnoid blood vessels, and intravascular presence of multiple adult parasites. From the morphological characteristics of the parasites and location in the leptomeninges, the parasite was identified as the nematode Gurltia paralysans.

São relatados dois surtos de paralisia progressiva dos membros posteriores em gatos (Felis catus), causada por meningomielite parasitária no Uruguai. Os estudos de casos ocorreram entre os anos 2008 e 2009, respectivamente, nas zonas rurais de Fray Bentos (33º 07' 40,39" S) e foram caracterizados por paralisia dos membros posteriores. Esta paralisia era progressiva e tinha evolução crônica de aproximadamente 12 meses, até que os animais vinham a óbito ou eram eutanasiados. Os sintomas clínicos começaram com ataxia dos membros posteriores, com movimentos laterais, terminado em paralisia total. Em 2009, dois animais foram encaminhados para necropsia. Os achados histopatológicos foram caracterizados por severa mielite na medula espinhal lombar com manguitos perivasculares linfocitarios e necrose da substância branca, severa meningite não supurativa com trombos nos vasos sanguíneos subaracnóideos, e presença intravascular de múltiplos parasitos adultos. De acordo com as características morfológicas dos parasitos e localização nas leptomeninges, este foi identificado como um nematóide da espécie Gurltia paralysans.