Efficacy of a novel topical combination of fipronil, (S)-methoprene, eprinomectin and praziquantel against feline urinary bladder worm (Capillaria plica) infection.

Infection with urinary capillarid bladder worms has been observed in cats worldwide. Although considered as generally causing no or little harm, infection with urinary capillarids may be associated with clinical disease which requires an appropriate treatment including the use of anthelmintics. Therefore, the efficacy of a novel topical combination formulation of fipronil 8.3% (w/v), (S)-methoprene 10% (w/v), eprinomectin 0.4% (w/v), and praziquantel 8.3% (w/v) (BROADLINE(®), Merial) was evaluated against urinary capillarids in naturally infected cats. Sixteen European Short Hair cats (5 male, 11 female) with capillarid eggs in their urine pre-treatment were included in the study. At the time of treatment, the cats were approximately ten months to eight years old and weighed 1.6-3.6 kg. Cats were ranked based on decreasing bodyweight and then randomly allocated within replicates of two animals to one of the treatment groups. Each cat in the treated group received one topical application of the combination product at the minimum therapeutic dose of 0.12 mL/kg body weight delivering 10mg fipronil+12 mg (S)-methoprene+0.5mg eprinomectin+10mg praziquantel per kilogram of body weight while the cats allocated to the control group remained untreated. For parasite recovery, identification and count, cats were euthanized humanely 14 days after treatment. All untreated cats harboured Capillaria plica in their urinary bladders (range 4-12), while no capillarids were recovered from the eight treated cats. Thus, the efficacy of the novel topical combination against C. plica was 100%. All cats accepted the treatment well based on post-treatment observations and daily observations thereafter. No adverse events or other health problems were observed during the study.

Calodium hepaticum (Nematoda: Capillariidae) in synanthropic rodents (Rattus norvegicus and Rattus rattus) in Eastern Amazonia / Primeiro relato de Calodium hepaticum (Nematoda:Capillariidae) em roedores sinantrópicos (Rattus norvegicus e Rattus rattus) na amazonia oriental

Calodium hepaticum (syn. Capillaria hepatica) is a trichurid nematode that parasitizes the hepatic parenchyma of rodents and other mammals. Infections in humans are rare, although they have been reported worldwide. A number of factors contribute to the distribution of this zoonosis, particularly the presence of dense populations of rodents associated with relatively poor urban environments, such as those found in parts of the northern Brazilian city of Belém in the eastern Amazon Basin. This study quantified Calodium infections in commensal synanthropic rodents in Belém. Rodents were captured in three neighborhoods characterized by poor public sanitation and the city's highest incidence of human leptospirosis. A total of 50 rodents were captured (26 Rattus rattus and 24 R. norvegicus), and 23 (10 R. rattus and 13 R. norvegicus) presented macroscopic lesions typical of C. hepaticum. Light microscopy of fresh samples and histological specimens permitted the identification of larvae and adult specimens containing numerous eggs with a double-striated shell and bipolar opercula with plugs. This is the first report of C. hepaticum in R. rattus and R. norvegicus from the Amazon Basin, and it shows a considerable risk of transmission to the local human population.

Calodium hepaticum (syn. Capillaria hepatica) é um nematódeo trichurídeo parasito de parênquima hepático de roedores e outros mamíferos. As infecções em humanos são raras, mas são relatadas em diversas regiões do mundo. Numerosos fatores contribuem para a distribuição desta zoonose, particularmente, uma densa população de roedores associada com ambientes urbanos com carência de saneamento básico, tais como aqueles encontrados em algumas cidades da região Norte do Brasil, como a cidade de Belém, localizada na Amazônia Oriental. Este estudo quantifica e demonstra a infecção por Calodium em roedores comensais sinantrópicos, de três bairros da cidade de Belém, Estado do Pará, com carência de saneamento público e alta incidência de leptospirose humana. Um total de 50 roedores foram capturados para análise (26 Rattus rattus e 24 R. norvegicus) e destes, 23 (10 R. rattus e 13 R. norvegicus) apresentaram típicas lesões hepáticas, macroscópicas, causadas por C. hepaticum. A análise de amostras por microscopia de luz direta e histopatológica do fígado dos roedores permitiu a identificação de espécimes desse parasito em fase larvar e adulta, além de numerosos ovos apresentando dupla casca estriada e dois tampões operculares. Este é o primeiro registro da ocorrência de C. hepaticum in R. rattus and R. norvegicus na região Amazônica, alertando para um considerável risco de transmissão para a população humana.

Capillaria hepatica in man--an overview of hepatic capillariosis and spurious infections.

Capillaria hepatica (syn. for Calodium hepaticum) is a zoonotic nematode parasitizing in the livers of rodents as main hosts and in numerous other mammals including humans. It is the causative agent of the rare conditions of hepatic capillariosis and spurious C. hepatica infections in humans. In this review, 163 reported cases of infestations with this parasite (72 reports of hepatic capillariosis, 13 serologically confirmed infestations and 78 observations of spurious infections) are summarized with an overview on the distribution, symptoms, pathology, diagnosis, serology and therapy of this rare human pathogen.

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.

Parasitic lesions of bovine liver attributed to capillaria species.

Among meat inspectors in Hokkaido, Japan, the term "bovine parasitic hepatitis" (BPH) has long been used to refer to a hepatic disorder characterized by multiple small yellowish lesions. However, the aetiology is unknown. By means of detailed histopathological examination, fragments of parasitic worms resembling Capillaria were detected in nine (2.25%) of 400 livers showing BPH lesions. Histologically, the degenerative lesions showed eosinophilic papillary endothelial hyperplasia of the interlobular veins and eosinophilic membranous structures in the eosinophilic granulomatous areas of inflammation. These characteristic findings differed from those of hepatic capillariasis of other animal species. BPH was found in 5-20% of milk cows examined throughout Hokkaido, and was also detected in cattle from another prefecture and from Australia. Possibly the same parasitic disorder, albeit undiagnosed, is more widespread.

Parasite biodiversity in Rattus spp caught in wet markets.

Rattus spp trapped in wet markets in Quiapo, Manila and Balayan, Batangas had ectoparasites, Echinolaelaps echidnius (mite), and Polyplax spinulosa (louse). The endoparasites identified were Hymenolepis diminuta; the acanthocephalan Moniliformis moniliformis; Taenia taeniaeformis strobilocercus larvae and Capillaria hepatica in liver; Trichosomoides crassicauda of the urinary bladder; Sarcocystis sp of muscle tissue; and two different species of stronglyloid-looking intestinal nematodes. Rats had 100% infection with C. hepatica and T. taeniaeformis, exhibiting high parasitemia. The co-existence of rats with diverse parasitic species is reflective of the host's capability to support parasites' behavioral, physiological, and developmental needs. Despite heavy infection with intestinal parasites, and marked hepatic tissue damage owing to severe capillariasis and strobilocercus larval infection, all rats appeared healthy and agile, suggestive of a well-established rat host-parasite relationship. In view of the diversity and zoonotic nature of rat parasites, and the impoverished conditions prevailing in communities where Rattus spp survive and proliferate, they can readily facilitate parasite transmission to humans and other susceptible animal hosts.

Capillaria hepatica: an experimental study of infection in white mice.

C. hepatica were found in 15.8% of wild caught rats. Experimental studies showed that the host reaction started specifically against developing worm as early as the 9th day post infection. Eggs started to develop inside uterus in the 3rd week P.I. The second month of infection was the maximum growth and activity of worm, egglying, severe liver destruction and necrosis, degeneration, granuloma formation as well as the greatest humoral and cellular responses of the host. By the third month P.I., there was a gradual increase of the fibroblastic activity around the already formed granuloma and a decrease of antibody level in peripheral blood. Areas of hepatic regeneration started between the fibrotic granulomas and the liver enzymatic reactions returned gradually to their normal levels. Viable eggs were seen until the eighth month of infection free or surrounded by fibrous tissue.