# Capillaria hepatica—A Neglected Zoonotic Parasite

## TL;DR

Capillaria hepatica is a neglected zoonotic parasite that causes severe liver disease in humans and animals, with challenges in diagnosis and underreported cases.

## Contribution

This study provides a comprehensive review of the epidemiology, diagnosis, and treatment of Capillaria hepatica infections.

## Key findings

- Capillaria hepatica has a worldwide distribution and primarily infects rodents, with Rattus norvegicus as a main carrier.
- Children are more susceptible to infection, and current diagnostic methods face limitations due to non-specific symptoms.
- The parasite's complex life cycle and biological features contribute to its pathogenicity and difficulty in control.

## Abstract

Capillaria hepatica is an important but overlooked zoonotic parasite. Infection with Capillaria hepatica can lead to severe liver disease and even death. Due to its non-specific clinical manifestations and the difficulty of its diagnosis, its actual incidence is seriously underestimated. In this study, the epidemiology of Capillaria hepatica infection in humans and animals is carefully investigated, and the pathogenesis, diagnosis, and treatment of hepatic capillariasis are described in detail. This article provides readers with insights into the unique life cycle and biological characteristics of this parasite, which may help to improve the understanding and control of this parasitic disease.

As an important zoonotic parasite, Capillaria hepatica poses a threat to human health that cannot be ignored due to its association with high mortality and serious damage to the liver, although there are relatively few human infections. The infection rate of Capillaria hepatica in rodents is very high, which poses a great threat to the health of rodents, and Rattus norvegicus has been found to be the main group carrying Capillaria hepatica. Capillaria hepatica’s unique biological characteristics, including its morphological features and complex life history, determine the specificity of its infection and pathogenicity. In terms of epidemiology, Capillaria hepatica has a worldwide distribution, a wide variety of hosts (mainly rodents), and various transmission routes, all of which increase the difficulty of its prevention and control. Children are more likely to be infected by it, and there is little gender difference among the infected population. Although there are a variety of diagnostic methods for hepatic capillariasis, all of them have certain limitations. In addition, due to its non-specific clinical manifestations, early accurate diagnosis of hepatic capillariasis is still a challenge. This article reviews the biological characteristics and pathogenic mechanism of Capillaria hepatica, the epidemiology of human infection, the epidemiology of animal infection, and the diagnosis and treatment of hepatic capillariasis, so as to provide a useful reference for related research and clinical practice.