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The hepatic nematode Calodium hepaticum is a zoonotic parasite primarily parasitising small mammals, but it can infect a wide range of mammal species, including humans. Due to its specific life cycle and transmission pattern, it is one of the least studied helminths in the world. The only documented findings of C. hepaticum from Slovakia (former Czechoslovakia) come from the 60s and 70s of the 20th Century, including nine human cases of the infection reported post-mortem . The present study was conducted in the area of these original records in the Tatra National Park (TANAP) and the Košice Zoo. In TANAP, 484 small mammals of six shrew species (Insectivora: Soricidae) and eight rodent species (Rodentia: Muroidea) were collected. In the Košice Zoo, 163 rodents from 10 species were sampled. All specimens were examined for the presence of C. hepaticum eggs using the artificial digestion method. The parasite was recorded in two shrew species ( Sorex araneus and Neomys fodiens ) and five rodent species ( Arvicola amphibius , Microtus agrestis , Clethrionomys glareolus , Apodemus flavicollis , and Rattus norvegicus ) from TANAP, while in the Košice Zoo only a single individual of R. norvegicus was found to be infected., Competing Interests: The authors declare that they have no known competing financial interests or personal relationships that could have influenced the outcomes of this study., (© 2024 The Authors.)

Objective: To investigate the prevalence of Calodium hepaticum (C. hepaticum) in rodents and insectivores from Wuhan section of the Yangtze River in China, and to provide evidence for the prevention and treatment of hepatic Calodium infection. Methods: Rodents and insectivores were captured from three selected Yangtze River beaches using mousetraps. The three survey sites were divided into six areas according to natural conditions, with 60 mousetraps placed in each area. The liver lesions in the captured rodents were observed by the naked eye and the eggs in the liver tissue were observed by microscopic examination. Results: A total of 1 080 mousetraps were placed, and 1 075 mousetraps were retrieved, with the retrieve rate as 99.5%. A total of 101 Apodemus agrarius, 12 Rattus norvegicus, and 9 Crocidura attenuata were caught. The average density of rodents and insectivores was 10.5% and 0.8%, respectively. DNA of egg nodules from infected rodents showed 98% similarity with that of C. hepaticum 18S rRNA (LC425008.1). One Rattus norvegicus was infected with C. hepaticum, with an infection rate of 3.23% in the Erqi river beach; the other two beaches did not show the incidence of C. hepaticum. Conclusions: The monitoring of C. hepaticum in the Yangtze River beaches should be strengthened to reduce the risk of human C. hepaticum infection.

Capillaria hepatica is a globally distributed zoonotic nematode parasite that most commonly infects feral and native rats. Soil contact, pica, and living in close proximity to rat populations are risk factors for human infection. Larval nematodes and eggs that were morphologically consistent with C. hepatica were observed microscopically in livers of stranded southern sea otters (Enhydra lutris nereis) from California. Large (90–100 × 45–55 μm), barrel-shaped non-embryonated parasite eggs with large polar prominences and a roughened or striated surface, or 105–120 μm diameter larval aphasmid nematode profiles with a prominent stichosome and hypodermal bands were observed in the livers of three otters. The liver of a fourth animal exhibited serpiginous tracts of necrosis, micro-cavitation and pleocellular inflammation, with intralesional linear eosinophilic material that resembled cuticle from degenerating metazoan parasites. Capillaria hepatica-associated hepatitis and capsular adhesions were the cause of death for one otter, and parasite-associated liver lesions were observed in all cases. All infected otters were adult females that stranded from 2006 through 2016 at multiple sites along the central California coast. All cases stranded from December through May; during and soon after peak seasonal precipitation and land-sea runoff in California. This same seasonal pattern has been reported for other land-based parasites infecting southern sea otters. Neither C. hepatica, nor any similar nematodes have been reported from marine mammals, and southern sea otters are not typical hosts for C. hepatica or any other nematode parasites. The most likely route of exposure was via freshwater runoff containing embryonated eggs liberated from predated or decomposing terrestrial hosts, especially rats. Similar to the land-based parasites Toxoplasma gondii and Sarcocystis neurona, C. hepatica eggs may be concentrated and transmitted through filter-feeding marine invertebrates that serve as southern sea otter prey, which may also pose an unrecognized public health risk for people who consume these species.

Hepatic capillariasis is a rare and neglected zoonosis affecting wild and synanthropic small rodents. It is caused by infection with Calodium hepaticum in liver. Despite the worldwide distribution of the host Rattus norvegicus (brown or street rats) in the urban area, the epidemiological status of this parasitosis remains unknown. In the present study, we examined a total of 27 brown rats from the city centre and a garden (four km from the city centre) of Marseille, France. All rats were autopsied and 52% showed the presence of C. hepaticum eggs in the liver. This result draws general attention to public health risks, since street rats are living near the human population.

Calodium hepaticum is a zoonotic nematode with a worldwide distribution. Although the host range of C. hepaticum includes a wide spectrum of mammals (including humans), this parasite is predominantly associated with the families Muridae and Cricetidae. Several Sigmodontinae species from Argentina were found to be infected by C. hepaticum , with a high prevalence in Akodon azarae . The present study focuses on C. hepaticum eggs from natural infection of three species of sigmodontine rodents from Argentina. Eggs were genetically characterized (intergenic 18S rRNA region). The objectives of this work are: (i) to propose a new analytical methodology; and (ii) to morphologically characterize C. hepaticum eggs, from three Sigmodontinae species ( A. azarae , Calomys callidus and Oligoryzomys flavescens ). Analyses were made by the Computer Image Analysis System based on the new standardized measurements and geometric morphometric tools. The resulting factor maps clearly illustrate global size differences in the parasite eggs from the three Sigmodontinae species analysed. The degree of similarity between egg populations was assessed through pairwise Mahalanobis distances, showing that the largest distances were detected between parasite eggs from C. callidus and O. flavescens . Herein, the phenotypical plasticity of C. hepaticum eggs is shown. Significant positive correlations were obtained between each egg parasite principal component 1 and rodent corporal characteristics: weight; liver weight; rodent length; and rodent body condition. The usefulness of the geometric morphometric analysis in studies of the relationship between C. hepaticum and its host must be highlighted. The high prevalence observed in A. azarae , associated with the wide size range of the parasite eggs evidenced by principal component analysis, suggests A. azarae to be the Sigmodontinae host species that plays the most important role as reservoir host for C. hepaticum in the New World.

Objective: To investigate the prevalence of Calodium hepaticum (C. hepaticum) in rodents and insectivores from Wuhan section of the Yangtze River in China, and to provide evidence for the prevention and treatment of hepatic Calodium infection. Methods: Rodents and insectivores were captured from three selected Yangtze River beaches using mousetraps. The three survey sites were divided into six areas according to natural conditions, with 60 mousetraps placed in each area. The liver lesions in the captured rodents were observed by the naked eye and the eggs in the liver tissue were observed by microscopic examination. Results: A total of 1 080 mousetraps were placed, and 1 075 mousetraps were retrieved, with the retrieve rate as 99.5%. A total of 101 Apodemus agrarius, 12 Rattus norvegicus, and 9 Crocidura attenuata were caught. The average density of rodents and insectivores was 10.5% and 0.8%, respectively. DNA of egg nodules from infected rodents showed 98% similarity with that of C. hepaticum 18S rRNA (LC425008.1). One Rattus norvegicus was infected with C. hepaticum, with an infection rate of 3.23% in the Erqi river beach; the other two beaches did not show the incidence of C. hepaticum. Conclusions: The monitoring of C. hepaticum in the Yangtze River beaches should be strengthened to reduce the risk of human C. hepaticum infection. [ABSTRACT FROM AUTHOR]

The nematode Calodium hepaticum and the cestode Taenia taeniaeformis are zoonotic helminths primarly found in the liver of common wild rats. Most reports on these helminth species with cosmopolitan distribution are from Asia, and there is paucity of data for Europe. Wild Norway rats (Rattus norvegicus) from urban and suburban habitats of the Belgrade area were examined for the presence of Calodium hepaticum and Taenia taeniaeformis larvae liver infections. The presence of visible cysts and a histomorphology of parasite-related inflammatory liver responses were sought as signs of infection. The total prevalence of infection was 10.9% (C. hepaticum) and 29.9% (T. taeniaeformis), with no differences between the sexes. No difference in the annual prevalence of both helminth species was noted. Data obtained in this study provide new information relevant to wild Norway rats as sources of C. hepaticum and T. taeniaeformis liver infection in this geographic area, and, in a wider context, in Europe. .

This study aims to report the incidence of Calodium hepaticum among dogs and cats, pets or stray animals, captured by the Zoonosis Control Center (CCZ) in Lages, Santa Catarina, Brazil. Fecal samples from 108 pet dogs and eight pet cats, and from 357 stray dogs and 97 stray cats, captured by CCZ, were analyzed within the period from July 2010 to November 2012. Coproparasitological exams were performed by techniques of sedimentation, centrifuge-flotation, and simple flotation. Among 465 fecal samples from dogs and 105 from cats, the overall spurious infections for C. hepaticum eggs were 1.05%. For dogs, this positivity was 0.43% and for cats it was 3.81%. The two positive dogs were stray and out of the four cats, three were stray and one was a pet. Although the occurrence of C. hepaticum eggs was low, these data reveal the existence of infected rodents, especially in public places, since, out of the six infected animals, five (83.33%) were stray. These results are discussed and analyzed with an emphasis on the risk to public health.

The nematode Calodium hepaticum (syn. Capillaria hepatica) is a zoonotic helminth found mainly infecting rats. It was studied the prevalence of C. hepaticum infection in Rattus norvegicus in an urban area of Rio de Janeiro (Brazil), with low urban planning and sanitation. The presence of C. hepaticum was identified through visible yellowish-white lesions in liver tissue and histological analyses. The total prevalence of infection was 45%, with no significant differences between sex and age. The presence of infected rodents near the peridomestic area poses substantial risk to human health.

Calodium hepaticum (syn. Capillaria hepatica) is a nematode of the Capillariidae family that infects rodents and other mammals. In Brazil, human spurious infections of C. hepaticum have been detected in indigenous or rural communities from the Amazon Basin, but not in the southern states of the country. Here, we report the highest occurrence (13.5% of 37 residents) of C. hepaticum human spurious infection detected in Brazil and the first record in a southern region, Guaraqueçaba. The finding is explained by the area being located in the Atlantic Forest of the state of Paraná, surrounded by preserved forests and because the inhabitants consume the meat of wild mammals.

Abstract Background Capillaria hepatica is a zoonotic parasite in humans and animals and has a worldwide distribution. However, infections in mammals apart from rodents, which are natural hosts of the parasite, have rarely been reported. This report describes the first known case of C. hepatica infection in a horse in Japan. Case presentation A 3-year-old filly without clinical signs was presented at a slaughterhouse in Japan. Gross examination revealed white to tan nodules 0.5 to 1.5 cm in diameter in the parenchyma of the liver. Histologically, the nodules had mature fibrous capsules and consisted of multifocal to coalescing granulomatous inflammations with numerous nematode eggs. The eggs were barrel shaped with an opercular plug on each end and double-layered shells; these findings are consistent with the features of C. hepatica eggs. Conclusions To our knowledge, this is the first case of C. hepatica infection in a horse in Japan. The pathological findings confirmed the presence of this pathogen in this part of the world, and they highlight the importance of this nematode in the differential diagnosis of hepatic granulomatous lesions in horses.

Subsistence hunting is the main source of protein for forest reserve dwellers, contributing to the development of spurious infections by Calodium hepaticum, frequently associated with the consumption of the liver from wild mammals. The prevalence of infections by soil-transmitted helminths (STHs) and intestinal protozoa is considered an indicator of the social vulnerability of a country, besides providing information on habits, customs and quality of life of a given population. Intestinal parasites mostly affect poor rural communities with limited access to clean water and adequate sanitation. This study reports the results of a parasitological survey carried out in 2017 and 2019, in two municipalities (Xapuri and Sena Madureira) in Acre State. Stool samples were collected from 276 inhabitants. Upon receipt, each sample was divided into two aliquots. Fresh samples without preservative were processed and examined by the Kato-Katz technique. Samples fixed in 10% formalin were processed by the spontaneous sedimentation and the centrifugal sedimentation techniques. Calodium hepaticum eggs were found in three stool samples. The overall STH prevalence was 44.9%. The hookworm prevalence (19.2%) was higher than that of Ascaris lumbricoides (2.5%) and Trichuris trichiura (0.7%), an unexpected finding for municipalities belonging to the Western Brazilian Amazon. When considering parasites transmitted via the fecal-oral route, Endolimax nana and Entamoeba coli showed the highest positivity rates, of 13% and 10.9%, respectively. This study is the first report of spurious infection by C. hepaticum among forest reserve dwellers that consume undercooked liver of lowland pacas. Additionally, this is the first report of Blastocystis sp. in Acre State.

Human hepatic capillariosis due to Calodium hepaticum is rarely described in Africa, probably because of the lack of diagnosis tools. However, it is known that the animal reservoir is made up of rodents. During a study performed on 24 black rats (Rattus rattus) trapped in Rethy (CongoDR) and 20 Gambian pouched rats (Cricetomys gambianus) in Dakar (Senegal), macroscopic and histological hepatic lesions of capillariosis were found in 8 of these rodents (3 in Rethy and 5 in Dakar). These results led us to propose, besides hygiene measures, an epidemiologic survey of this serious parasitosis, particularly in children, in the course of serological and/or coproscopic investigations.

Calodium hepaticum já foi relatado parasitando o parênquima hepático de diversas espécies de mamíferos, porém é infrequente em cães. O presente artigo tem o objetivo de descrever dois casos de capilariose hepática em cães, diagnosticados em um período de um mês na região de Santa Maria, Rio Grande do Sul, Brasil. O primeiro cão apresentava sintomatologia clínica de insuficiência cardíaca, e ovos de Calodium hepaticum foram encontrados ocasionalmente no exame histopatológico do fígado. O segundo animal apresentava mucosas ictéricas e ascite. No hemograma, ficou evidente a presença de anemia arregenerativa e, na avaliação de bioquímica sérica, percebeu-se aumento de fosfatase alcalina, alanina aminotransferase e hipoalbuminemia. A análise do liquido cavitário foi compatível com transudato modificado. No exame histopatológico, foram observados numerosos ovos bioperculados de Calodium hepaticum, dispostos aleatoriamente pelo parênquima hepático, com reação granulomatosa e fibrosa adjacente aos ovos. A existência de maior número de cães infectados demonstra a necessidade de controle da população de roedores.Calodium hepaticum has been reported as a parasite of the hepatic parenchyma of many mammal species, but it is not frequent in dogs. The present article aimed to describe two cases of hepatic capillariasis in dogs, diagnosed in a period of one month, in e Santa Maria city, Rio Grande do Sul state, Brazil . The first dog presented clinical sintomathology of cardiac insufficiency and Calodium hepaticum eggs were occasionally found by histopathological examination of the liver. The second animal presented icteric mucous membranes and ascites. The hemogram revealed non-regenerative anaemia and in the biochemistry serum were observed elevation of alkaline phosphatase, alanina aminotransferase and hypoalbuminemia. The cavitary liquid analysis was compatible with modified transudate. In the histopathological examination, numerous bioperculated eggs of Calodium hepaticum were observed aleatorily distributed in the hepatic parenchyma, with granulomatous and fibrous reaction adjacent to the eggs. The occurrence of two cases in a short period of time suggests that other dogs may be infected and requires a rodent population control.

Calodium hepaticum (Bancroft, 1893)--commonly known as Capillaria hepatica is a nematode parasitising in liver of rodents, some domestic and wild mammals: Insectivora, Carnivora, Artiodactyla and Primates including human as well. C. hepaticum is the only nematode--geohelminth, which for the continuity of the life cycle needs the death of the host being the intermediate and final host at the same time. The eggs of the parasite deposited by female worms in liver of the host became entrapped in fibrotic tissue. C. hepaticum is a cosmopolitic nematode. Rats and mice (domestic and field) are the main hosts of this parasite, the prevalence of infection can be very high e.g. Rattus norvegicus--100% in the Baltimore Zoo (Farhang-Azad 1977) as well as from the urban area of Milan (Italy)--the prevalence of infection was 36% (Ceruti et al. 2001). Hepatic capillariasis was not recorded in our country but its existence seems to be very probable.

BACKGROUND: Calodium hepaticum (syn. Capillaria hepatica) is a worldwide helminth parasite of which several aspects of transmission still remain unclear. In the Amazon region, the mechanism of transmission based on the ingestion of eggs present in the liver of wild mammals has been suggested as the cause of the spurious infections described. We performed an epidemiological investigation to determine the incidence, risk of spurious infection and the dynamics of transmission of C. hepaticum in a community of the Brazilian Amazon. METHODOLOGY/PRINCIPAL FINDINGS: Stool samples of 135 individuals, two dog feces and liver tissue from a peccary (captured and eaten by the residents) were analyzed by conventional microscopy. Dog feces were collected from the gardens of households presenting human cases of spurious C. hepaticum infections. Community practices and feeding habits related to the transmission of the parasite were investigated. The individual incidence of spurious infection was 6.7% (95% CI: 2.08-11.24). Cases of spurious infection were observed in 7.5% of the families and the household incidence was from 50% to 83.3%. The risk of spurious infection was 10-fold greater in persons consuming the liver of wild mammals (p = 0.02). The liver tissue of a peccary and one feces sample of a dog presented eggs of C. hepaticum. The consumption of the infected liver was the cause of the spurious infections reported in one household. CONCLUSIONS/SIGNIFICANCE: This is the first identification of a source of spurious infection by C. hepaticum in humans and we describe a high rate of incidence in household clusters related to game liver alimentary habits. The finding of a dog feces contaminating peridomiciliary ground suggests the risk of new infections. We conclude that the mechanism of transmission based on the ingestion of liver is important for the dynamics of transmission of C. hepaticum in the studied area.