Hepatic Capillaria hepatica (Bancroft, 1893) infection in cat (Felis catus)-histopathological findings and first report from Iran.

Capillaria hepatica (syn. Calodium hepaticum) is a globally distributed nematode with a high affinity to the liver of a wide range of mammalian hosts, including humans. Documented reports of the nematode in cats and associated histopathology are rare. Here, we describe a case of C. hepatica infection in a 5-year-old male stray cat from Iran. At post-car accident necropsy, all body parts appeared normal except for the liver, in which a few yellowish-white granulomatous nodules were observed through the capsule and in the organ. Histopathological examination of the tissue revealed a large number of clustered parasite eggs in the parenchyma. The barrel-shaped, un-embryonated eggs (55.19 × 28.37 µm), with inconspicuous caps at both ends, were covered with striated shells. The presence of ova in the liver tissue had resulted in the development of hepatic inflammation with hepatocellular necrosis associated with the development of multifocal granulomas. As predators of small rodents, the cats might have a significant role in the epidemiology of C. hepatica. Infection of hosts through ingestion of embryonated eggs in contaminated water, food, or soil is of major importance in the epidemiology of C. hepatica. Since the rare reports of feline infection have come mainly from accidental detection of the parasite, any hepatic disease presenting difficulties to find an etiological agent may virtually be associated with the infection with this little-known nematode.

Capillaria plectropomi n. sp. (Nematoda: Capillariidae), a new intestinal parasite of the leopard coral grouper Plectropomus leopardus (Serranidae) off New Caledonia.

A new nematode species, Capillaria plectropomi n. sp. (Capillariidae), is described from the intestine of the leopard coral grouper Plectropomus leopardus (Lacepède) from coral reefs off New Caledonia. The new species, belonging to the subgenus Neocapillaria Moravec, 1987, differs from other congeneric species of this subgenus from marine fishes mainly in the length (168-186 µm), shape and structure of the spicule. It is characterized, in the male, by the presence of two well-developed dorsolateral caudal lobes, a pair of lateral papillae, a heavily sclerotized spicule with many rough transverse grooves in the middle part, a spinose spicular sheath, and in the female, by eggs measuring 60-66 × 27 µm without protruding polar plugs. The buccal cavity contains a small finger-shaped stylet. Capillaria plectropomi n. sp. is the first known species of this genus parasitizing fishes of the perciform family Serranidae.

Artificial infection of chickens with Capillaria obsignata eggs embryonated in different media.

The present study investigated whether incubation media have an impact on infectivity of Capillaria obsignata eggs in chickens infected with gradually increasing doses. C. obsignata eggs collected from female worms were incubated either in formalin (0.5% or 2%) or in potassium dichromate 0.1% or in sulfuric acid 0.1N for three weeks (wk). One-day-old male chicks (N=92) were reared in a parasite-free environment, and infected with 0, 500, 1000 or 2000 eggs at an age of 3 wk. Post-mortem parasitological examinations were performed on day 28 p.i. Although all the infected birds harboured adult worms, their growth performance was not affected. Furthermore there was no significant interaction effect between incubation media and infection dose on worm establishment rates (P=0.080), while main effects of these two factors were significant (P<0.05). The average number of adult worms found in birds infected with the eggs incubated in potassium dichromate were significantly lower (P<0.001) than in formalin 0.5%, formalin 2% and sulfuric acid 0.1N. A higher (P<0.05) percentage of larvae could establish themselves in the intestines when the birds were infected with 500 eggs (40.5%) instead of 2000 eggs (26.2%), indicating density dependent effects. It is concluded that formalin (particularly 0.5%), and sulfuric acid can successfully be used as incubation media for C. obsignata eggs, whereas potassium dichromate impairs subsequent infectivity of the eggs. Although effects of media on the infectivity of the eggs were confirmed to be fairly repeatable, no harmful effect of infection was quantified on the host animal performance with the infection doses up to 2000 eggs.

Alterações iniciais da fibrose septal por Capillaria Hepatica (Bancroft, 1893) em ratos / Initial changes of septal fibrosis Capillaria hepatica (Bancroft, 1893) in rats

espaço-porta é o local de origem da fibrose em muitas doenças crônicas hepáticas. Essa área do fígado participa da drenagem linfática hepática e abriga diversos elementos celulares potencialmente fibrogênicos. Estudos sobre a fibrose hepática relacionados à infecção experimental de ratos pelo helminto Capillaria hepatica têm demonstrado que a fibrose começa em áreas portais com a distribuição de septos que sulcam o parênquima hepático se desenvolvendo em áreas próximas ao espaço de Disse. Entretanto, apesar de esta fibrose ocorrer de forma paralela aos sinusóides, estudos têm revelado que não apenas as células estreladas hepáticas participam da fibrose septal, mas também outros tipos celulares residentes nos espaços-porta. Diante destes aspectos, o presente estudo desenvolveu-se com o intuito de investigar a contribuição das células potencialmente fibrogênicas dos espaços-porta, nas fases iniciais da infecção, onde a fibrose se concentra. Para isso, foram utilizados fragmentos de fígado, em blocos parafinados, disponíveis nos arquivos do Laboratório de Patologia Experimental (CPqGM/Fiocruz) provenientes de ratos infectados com 800 ovos de Capillaria hepatica e foi possível observar que ocorreu a proliferação de colangiócitos e a concentração de miofibroblastos em áreas portais, além da ativação de células estreladas hepáticas, sendo todos os resultados vistos por meio da coloração de rotina HE, Picro-sírius vermelho e imunohistoquímica para α-actina de músculo liso, CD31 e GFAP.

Portal space is the local of origin for fibrosis in many chronic liver diseases. This area is involved with lymph drainage and contains several cell types, potentially fibrogenic. Experimental studies related to hepatic fibrosis during Capillaria hepatica infection in rats have suggested that the septal fibrosis indeed takes origin from portal spaces, with the distribution of the septs in the parenchymal region in proximity areas of Disse space. However, despite this fibrosis occurs in parallel to sinusoids, studies have revealed that not only the hepatic stellate cells participate in septal fibrosis, but also other resident cell types in the portal spaces. In face these aspects, the goal of present study was investigate the contribution of the cells potentially fibrogenic in the portal space, in the early phases of the infection. For this, blocks in paraffin available of the liver of rats infected with 800 eggs of Capillaria hepatica archived in the Laboratory of Experimental Pathology (Research Center Gonçalo Moniz, Fiocruz - BA), were utilized and it was observed that proliferation of colangiocytes and concentration of myofibroblasts occurred portal areas, in addition to the activation of hepatic stellate cells. All results were analised by routine staining HE, Sirius red and immunohistochemistry for α-SMA, GFAP and CD31.

The role of culture media on embryonation and subsequent infectivity of Capillaria obsignata eggs.

This study investigated whether infectivity of Capillaria obsignata eggs depends on media culture used for embryonation. Intact female worms were kept in one of following four media: 0.5 % formalin, 2 % formalin, 0.1 % potassium dichromate and 0.1 N sulfuric acid. Embryonation rates of the eggs were quantified either daily in intact females for 16 days, or weekly in disrupted females. Infectivity of the embryonated eggs was tested through an experimental infection of chickens with a single dose of 250 eggs/ bird. The vast majority of the eggs (>82 %) in the first two thirds of the uteri was able to complete embryonation, irrespective of the culture media used for incubation. However, only 32.6 % of total eggs could be harvested after disruption of the intact females. Embryonation rates of the eggs from disrupted worms were different among four culture media, with 0.1 N sulfuric acid resulting in the highest embryonation rate (44.2 %). All the experimentally infected birds harboured mature worms, with varying establishment rates depending on the culture media (P < 0.001). Incubation of the eggs in potassium dichromate 0.1 % resulted in a lower (P < 0.001) establishment rate (10.2 %) when compared with formalin (70.5 and 47.9 % for concentrations at 0.5 and 2 %, respectively) or with 0.1 N sulfuric acid (57.5 %). It can be concluded that most of the eggs in first two thirds of the uteri in the intact females have the potential to complete embryonation without being influenced by the culture media. However, disruption of the intact females results in lower number of harvestable embryonated eggs, with a considerable variation due to culture media used. With the exception of 0.1 % potassium dichromate, any of the three media, particularly 0.1 N sulfuric acid, can be suggested for embryonation of C. obsignata eggs.

An experimental type II mixed cryoglobulinemia with renal glomerulopathy in ICR mice triggered by Capillaria hepatica infection.

Type II mixed cryoglobulinemia is characterized by systemic vasculitis with deposition of cryoprecipitatable-immunoglobulins containing rheumatoid factor. Pathogenesis of type II mixed cryoglobulinemia has not yet been completely clarified because of the lack of an experimental animal. Here, we report an animal model of type II mixed cryoglobulinemia that is induced by experimental infection with Capillaria hepatica in ICR mice. Capillaria hepatica is a nematode that causes necrotic hepatitis in several mammals. In this study, mice experimentally infected with C. hepatica eggs developed cryoglobulinemia at 20 and 30 days post injection. Using immunological analysis, cryoglobulinemia in infected mice was classified as type II mixed cryoglobulinemia by detection of monoclonal IgM rheumatoid factor and IgA in the cryoprecipitate of serum. Using immunofluorescence, we observed an increase in the number of double-positive cells for µ heavy and κ light chains of immunoglobulin in the spleens of infected mice. Histopathologically, this model was characterized by glomerulopathy associated with intense deposition of IgM and IgA filling in capillary lumina. Ultrastructural analysis showed that glomerular deposits consisted of stacks of twisted microtubular structures. These serological and histological features resembled those of type II mixed cryoglobulinemia in human. This is the first experimental animal model of type II mixed cryoglobulinemia that will enable detailed studies on the pathogenesis of cryoglobulinemia.

Canine and feline infections by cardiopulmonary nematodes in central and southern Italy.

Capillaria aerophila, Aelurostrongylus abstrusus, Angiostrongylus vasorum and Dirofilaria immitis are cardiopulmonary nematodes affecting dogs and cats and presently emerging in several countries. The results obtained in 2009 - 2010 during a study aiming to investigate the occurrence of these nematodes in regions from Central (Marche and Abruzzo regions--Sites A and B, respectively) and southern (Apulia--Site C) Italy are here reported. A total of 534 and 436 individual faecal samples collected from dogs and cats were examined, together with 471 and 34 faecal environmental samples taken from dog shelters and catteries. One hundred and ninety-two individual blood samples were also collected from dogs. Faeces were examined using copromicroscopical flotations and Baermann technique, whereas blood samples were tested by Knott's method. Eggs of C. aerophila were detected in 1.48 % and 20 % (Site A), 8.67 % and 2.71 % (Site B), and 16.67 % and 0 % (Site C) of individual and environmental canine samples. C. aerophila was found in 2.90 % (Site A), 3.03 % (Site B) and 14.29 % (Site C) of individual cats. Larvae of A. vasorum were found in 0.96 % and 2.48 % of individual and environmental samples from Site B, respectively, while those of A. abstrusus in 1.82 % (Site A) and 9.96 % (Site B) of individual faeces. Microfilariae of Dirofilaria immitis, identified on the basis of key morphological and morphometric features, were detected in 2.56 % of samples collected from Site B. Despite the small sample size, these results indicate that cardiopulmonary nematodes occur in Central and southern Italy, thus they should be included in the differential diagnosis of pet cardiorespiratory diseases. Larger surveys are necessary to gain more information on the diffusion of these parasites, especially for C. aerophila and A. vasorum, for which the actual distribution is poorly known.

Dynamics of Capillaria-hepatica-induced hepatic septal fibrosis in rats.

INTRODUCTION: The pathogenesis of septal hepatic fibrosis, induced in rats by Capillaria hepatica infection, was studied with the aid of a large collection of stored paraffin blocks, representative of the different evolutive phases of fibrosis which appeared in 100% of infected rats. METHODS: Studies were conducted involving histology, immunohistochemistry, immunofluorescence and morphometric methods, in order to observe the dynamic behavior of the cellular and matrix components of fibrosis, over a one year period of evolution. RESULTS: Observation verified that septal fibrosis originates from several portal spaces simultaneously. Its origin and progression involve blood vessel proliferation (angiogenesis), multiplication of actin-positive cells (pericytes and myofibroblasts) and progressive collagen deposition. By the end of 4-5 months, a progressive decrease in all these components was observed, when signs of regression of septal fibrosis became more evident over time. CONCLUSIONS: Besides indicating the fundamental role played by angiogenesis in the pathogenesis of fibrosis, these morphological data concerning the dynamics of this C. hepatica experimental model proved to be adequate for future investigations regarding the functional aspects of fibrosis induction, progression and regression.

Dynamics of Capillaria-hepatica-induced hepatic septal fibrosis in rats / Dinâmica da fibrose septal hepática induzida por Capillaria hepatica em ratos

INTRODUCTION: The pathogenesis of septal hepatic fibrosis, induced in rats by Capillaria hepatica infection, was studied with the aid of a large collection of stored paraffin blocks, representative of the different evolutive phases of fibrosis which appeared in 100 percent of infected rats. METHODS: Studies were conducted involving histology, immunohistochemistry, immunofluorescence and morphometric methods, in order to observe the dynamic behavior of the cellular and matrix components of fibrosis, over a one year period of evolution. RESULTS: Observation verified that septal fibrosis originates from several portal spaces simultaneously. Its origin and progression involve blood vessel proliferation (angiogenesis), multiplication of actin-positive cells (pericytes and myofibroblasts) and progressive collagen deposition. By the end of 4-5 months, a progressive decrease in all these components was observed, when signs of regression of septal fibrosis became more evident over time. CONCLUSIONS: Besides indicating the fundamental role played by angiogenesis in the pathogenesis of fibrosis, these morphological data concerning the dynamics of this C. hepatica experimental model proved to be adequate for future investigations regarding the functional aspects of fibrosis induction, progression and regression.

INTRODUÇÃO: Um extenso material de patologia experimental arquivado em blocos de parafina, ilustrativo das diferentes fases da fibrose hepática septal, que 100 por cento dos ratos desenvolvem em seguida uma infecção com o nematódeo Capillaria hepatica. MÉTODOS: O material foi sistematicamente estudado com métodos morfológicos e morfométricos, no sentido de se verificar o comportamento dos elementos celulares e matriciais durante a evolução da fibrose hepática septal ao longo de um período de um ano. RESULTADOS: Foi constatado que a fibrose septal se origina de vários espaços porta ao mesmo tempo, com proliferação vascular (angiogênese), multiplicação de células actino-positivas (pericitos, miofibroblastas) e progressivo depósito de colágeno. Ao fim dos 4-5 meses há uma involução regressiva de todos estes indícios morfológicos, mas com alguns septos persistindo bem evidentes até o fim de um ano. CONCLUSÕES: Além de ilustrar o papel fundamental desempenhado pela angiogênese, o modelo se mostrou adequado para futuros estudos funcionais relacionados com a indução, progressão e regressão da fibrose hepática.

Pearsonema (syn Capillaria) plica associated cystitis in a Fennoscandian arctic fox (Vulpes lagopus: a case report.

The bladderworm Pearsonema (syn Capillaria) plica affects domestic dogs and wild carnivores worldwide. A high prevalence in red foxes (Vulpes vulpes) has been reported in many European countries. P. plica inhabits the lower urinary tract and is considered to be of low pathogenic significance in dogs mostly causing asymptomatic infections. However, a higher level of pathogenicity has been reported in foxes. A severe cystitis associated with numerous bladderworms was found in a captive arctic fox (Vulpes lagopus) originating from the endangered Fennoscandian arctic fox population. To our knowledge this is the first description of P. plica infection in an arctic fox.

Capillaria hepatica in China.

Capillaria hepatica (C. hepatica) is a parasitic nematode causing hepatic capillariasis in numerous mammals. Ecologic studies showed that the first hosts of C. hepatica were rodents, among which rats had relatively high infection rates, which explains why C. hepatica spreads globally. Anatomical studies showed that the liver was the principal site of colonization by these parasites and physical damage tended to occur. Although C. hepatica might lead to serious liver disorders, relevant clinical reports were rare, because of the non-specific nature of clinical symptoms, leading to misdiagnosis. This review mainly focuses on the biological characteristics and epidemiology of C. hepatica in China and histopathologic changes in the liver, with expectation of gaining a better understanding of the disease and seeking more effective treatment.

Pathogenesis of septal fibrosis of the liver. (An experimental study with a new model.).

Septal fibrosis is an important, frequent, and non-specific type of fibrosis associated with chronic liver diseases, but its pathogenesis is still poorly understood. An interesting model of septal fibrosis occurs in rats infected with the nematode Capillaria hepatica. This model was used to investigate the pathogenesis, site of origin, structure, and cell-types of septal fibrosis. Forty young adult Wistar rats were inoculated with 800 embryonated eggs of C. hepatica. Daily liver samples were obtained from the 20th to the 39th day after inoculation to cover the critical period when septal fibrosis usually starts. Routine histology, electron microscopy, immunohistochemistry, and indirect immunofluorescence were applied to the study of liver sections. Septal blood vessels were demonstrated by India ink perfusion of the portal vein system. Prominent angiogenesis was observed to precede collagen deposition. Besides angiogenesis and mesenchymal-cell mobilization, septal fibrosis was seen to originate from portal spaces and to course through acinar zone I in between sinusoids, inducing no alterations in them, with no evident participation of stellate hepatic cells. Septal fibrosis appeared as an adaptative type of response of the liver to chronic injury, which resulted in a new structure that is normal to other species and creates accessory vessels that drain portal blood into hepatic sinusoids.

Experimental hepatic fibrosis due to Capillaria hepatica infection (differential features presented by rats and mice).

Rats and mice are among the most susceptible hosts for the helminth Capillaria hepatica. More information on the similarities and differences between the hepatic pathology presented by these two parasite hosts are needed, since they may represent good models for the study of hepatic fibrosis. Early changes are similar for both hosts and are represented by necro-inflammatory lesions around dead parasites and their eggs and diffuse and intense reactive hepatitis. Although worms remain alive longer in mice than in rats, hepatic changes are more rapidly and deeply modulated in the former, even leading to almost complete disappearance of fibrosis. As for the rats, the modulation of the focal lesions is followed by the formation of septal fibrosis, a process where fine and long fibrous septa appear connecting portal spaces and central veins in such a way as to form a final morphologic picture of cirrhosis. Hepatic functional changes usually present good correlations with the morphologic findings at the different phases of the infection evolution. Therefore C. hepatica infection in rats and mice represent two different models of hepatic fibrosis and these differences, if properly known and understood, can be explored to answer different questions regarding several aspects of hepatic fibrosis.

Production of septal fibrosis of the liver by means of foreign protein injections into rats.

Similarities and differences in antigenic humoral responses and electrophoretic patterns between Capillaria hepatica and pig-serum were investigated as a contribution to the understanding of hepatic fibrosis induced by the parenteral administration of foreign proteins. Only two out of 10 rats receiving repeated intraperitoneal injections of an extract of Capillaria hepatica-infected mouse liver presented septal hepatic fibrosis (20%). Under the same experimental conditions, 4 out of 9 rats (44.4%) developed septal fibrosis following whole pig-serum administration. Injections of normal mouse liver extracts did not result in hepatic fibrosis. Since a 100% septal fibrosis rate is observed in experimentally Capillaria hepatica-infected rats, it appeared that Capillaria hepatica products continuously released from inside the liver creates a much more effective fibrosis inducing mechanism than the parenteral administration of such factors. Thus, repeated peritoneal administration of a foreign protein to rats would not reveal the full fibrogenic potential it may have under natural conditions.

Worm load and septal fibrosis of the liver in Capillaria hepatica-infected rats

Inocula, varying from 15 to 1,000 embryonated Capillaria hepatica eggs, were administered to young adult rats by gastric tube, in an attempt to investigate the influence of worm load in the production of septal fibrosis of the liver. Low doses of 15, 30 or 50 eggs were sufficient to produce septal fibrosis, but it appeared with variable degrees of intensity and always with focal distribution. Septal fibrosis became diffuse, progressive with time, and already well developed 40 days after infection, when 100 eggs or more were administered. However, higher inocula (200, 500 and 1,000 eggs) did not intensify septal fibrosis, although the number of parasitic focal lesions proportionally augmented

Hepatic capillariasis in children: report of 3 cases in Brazil.

Capillaria hepatica is a helminth that may cause an extremely rare condition of parasitic hepatitis. Only 29 cases have been published, 2 of them in Brazil. We report here 3 cases of children in Brazil with massive hepatic capillariasis who presented the characteristic triad of this type of infection, i.e., persistent fever, hepatomegaly, and eosinophilia. The diagnosis was made by liver biopsy. All children responded well after treatment with thiabendazole (case 1), albendazole (case 3), and albendazole in combination with a corticoid (case 2). Case 1 has been followed-up for 24 years, an event not previously reported in the literature.

Parasitological aspects of Capillaria philippinensis recovered from Egyptian patients.

Seven new cases of intestinal capillariasis were detected in Kasr El-Aini University Hospitals, Cairo, during the period from July 1997 to June 1998. A parasitological study concerning the morphological features of Capillaria philippinensis recovered from the stool of Egyptian cases was carried out. Eggs were separated, cultured and used to infect Oreochromis nilotica niloticus, a famous popularly consumed type of fresh water fish in Egypt in a trial for identification of the fish intermediate host for this parasite, but infection had not developed in the intestine of this species of fish.