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.

Canine bladderworm (Capillaria plica) infection associated with glomerular amyloidosis.

Capillaria plica (Trichuroidea: Capillariidae), commonly known as bladderworm, is a nematode rarely associated with clinical disease that resides in the lower urinary tract of wild and domestic canids. In the present paper a case of canine urinary capillariosis associated with glomerular amyloidosis is described. The dog, an 8-year-old, male, hunting Jagd terrier had a history of weight loss and diarrhoea and was referred to the University of Parma Teaching Veterinary Hospital (UPTVH). Clinical and laboratory tests shown here suggest that C. plica may be a contributing factor to glomerular amyloidosis.

Soboliphyme baturini infection does not affect the nutritional condition of American marten (Martes americana) in Alaska.

Soboliphyme baturini, a stomach-dwelling nematode of American martens (Martes Americana), reaches high levels of infection; however, its effects on the nutritional condition of the host are unknown. To understand the effects of this parasite on American martens, we collected S. baturini and measured abdominal fat deposits from 155 marten carcasses on Prince of Wales Island, southeastern Alaska, in the winter 2006-2007. We analyzed how the dried mass of abdominal fat varied as a function of S. baturini intensity. Parasite intensity and nutritional condition were not correlated; these results suggest that American martens were able to withstand even very high levels of S. baturini infection (up to 178 parasites per host).

Physiological responses of deer mice (Peromyscus maniculatus) to infection with Capillaria hepatica (Nematoda).

Negative effects due to infection have not been documented for most natural host-parasite associations. I performed an infection experiment to measure the physiological consequences of infection by Capillaria hepatica in deer mice (Peromyscus maniculatus gracilis). Compared to their uninfected siblings, infected mice displayed increased serum concentrations of alkaline phosphatase and total proteins and reduced concentrations of albumin. Infected mice also had higher hematocrits and enlarged livers and spleens. There was no difference in swimming endurance between infected and control animals, possibly because mice did not perform at maximum aerobic capacity. Sex differences in alkaline phosphatase and albumin levels suggest that females are more sensitive to similar burdens of C. hepatica. Different hematocrit responses between mice from 2 localities suggest that historical associations can lead to evolutionary change in pathophysiology caused by this nematode. Further experiments would reveal whether these disturbances lead to reductions in host fitness.

Clinicopathological features and histopathology of experimental hepatic capillariasis in muskrats (Ondatra zibethicus).

Ten muskrats (Ondatra zibethicus) each were infected with 17,000 eggs (long-term study) and eight muskrats each were infected with 8,000 eggs (short-term study) of Capillaria hepatica (Nematoda). Food intake, body weight, and selected clinicopathological parameters were measured every 2 days for 28 days in the short-term study and every 14 days for 184 days in the long-term study. Muskrats in the short-term study had moderate to severe necrotizing granulomatous hepatitis associated with mild anorexia and weight loss, varying degrees of leukocytosis with eosinophilia and elevation of serum alanine and aspartate aminotransferases. No significant changes in packed cell volume, hemoglobin, total plasma protein, albumin, blood urea nitrogen, bilirubin, lactate dehydrogenase or alkaline phosphatase were found among animals from the short-term study. Muskrats in the long-term study had severe necrotizing granulomatous hepatitis associated with marked anorexia, weight loss and 60% mortality over 39 days post-inoculation (PI); animals that survived for 184 days did not return to pre-inoculation body weights despite returning to normal food intake. Hepatic lesions at 184 days PI consisted of minimal to severe liver replacement by C. hepatica eggs. No statistically significant differences in values of clinical parameters between inoculated animals and a non-inoculated control group from the long term study were found.

Evaluation of a nematode (Capillaria hepatica Bancroft, 1893) as a control agent for populations of house mice (Mus musculus domesticus Schwartz and Schwartz, 1943).

Sudden, large-scale infestations of house mice (Mus musculus domesticus) occur irregularly in the cereal-growing regions of Australia, resulting in substantial economic losses. Mathematical modelling has been used to evaluate the use of the liver nematode Capillaria hepatica as a potential agent for the biological control of mouse populations. The models suggest that C. hepatica is unlikely to be successful as a single-release control agent: instead, the parasite would need to be released when it becomes apparent that an outbreak is likely. Stage-structured models, including time delays and seasonal mouse demographic parameters, suggest that the parasite may be successful as a control agent, provided it can be introduced into the mouse population at least one year before an outbreak occurs. The optimum time for introduction is in summer or autumn. Some generalisations of this work are discussed. A parasite which affects fecundity alone is unlikely to be a good control agent, because it will destabilize the host population. Macroparasites may be unable to spread sufficiently rapidly to control sudden rises in vertebrate populations.