What are the other Names for this Condition? (Also known as/Synonyms)

• Calodium Hepaticum Infection
• Capillaria Infection of Liver
• Infection by Capillaria Hepatica

What is Hepatic Capillariasis? (Definition/Background Information)

• Capillariasis or Capillaria infection is caused by certain parasitic organisms, called nematodes or roundworms, belonging to the genus Capillaria. Three forms of Capillaria infection have been identified based on the causative subspecies. These include:
  • Hepatic Capillariasis or Capillaria hepatica Infection
  • Intestinal Capillariasis or Capillaria philippinensis infection
  • Pulmonary Capillariasis or Capillaria aerophila infection
• Hepatic Capillariasis is a rare infection of the liver caused by the nematode Capillaria hepatica (also known as Calodium hepaticum in some parts of the world). These nematodes are parasitic roundworms that live inside animals, such as rats, foxes, dogs, monkey, and pigs, and rarely humans. C. hepatica eggs are passed through feces of infected animals and humans
• The eggs can become infective once in soil, where such infected feces are deposited after around 30 days. Humans are infected when they consume contaminated food, water, or ingest contaminated soil inadvertently. Soil ingestion may also occur as a result of pica, which is an eating disorder that causes people to eat non-food materials such as soil, dirt, or clay
• If a human is infected with only one C. hepatica worm, then there are typically no signs and symptoms noted. However, if multiple worms are present, especially egg-laying female worms, it can result in severe symptoms affecting the liver
• If left untreated, Hepatic Capillariasis can lead to life-threatening conditions such as hepatitis and liver function failure. Without suitable timely intervention and treatment, Hepatic Capillariasis is known to be a fatal infection
• Analysis of liver tissue through a biopsy is the chief diagnostic method for Hepatic Capillariasis. On recognition of this liver condition, it is treated using antiparasitic medications and steroids. With appropriate treatment, the affected individuals are known to make a full recovery and the outcomes are good

Who gets Hepatic Capillariasis? (Age and Sex Distribution)

• Hepatic Capillariasis is an extremely rare disease. Even though, the causative nematodes are distributed globally in forested regions, there have only been a few cases reported in humans from around the world
• The condition is usually reported from hot and humid areas of North and South America (Brazil, Mexico, and USA), Asia (India, Japan, and Korea), and Europe (Italy, Germany, and Czechoslovakia)
• Individuals of any age group and both male and female gender are susceptible to developing the infection. Children, with a tendency to have less hygienic behavior, are generally more likely to contract Hepatic Capillariasis than adults
• No racial or ethnic predilection is reported in the occurrence of this infection. People that live in areas of poor hygiene and high rodent populations are more likely to encounter C. hepatica nematodes

Individuals in the United States and other developed nations are rarely known to develop Hepatic Capillariasis. In such cases, the infection sets in from travel to the affected/endemic regions or following contact with infected individuals.

What are the Risk Factors for Hepatic Capillariasis? (Predisposing Factors)

The following are some risk factors for Hepatic Capillariasis: 

• Living in areas of poor sanitation, toilet facilities, and hygiene including having large rodent populations. C. hepatica can be found in the following locations:
  • Tropical environments
  • Terrestrial areas
  • Urban environments
  • Agricultural and rural areas
  • Forests
  • Caves
• Poor toilet hygiene - contacting feces and not washing hands thereafter 
• Pica: Individuals that are diagnosed with pica, an abnormal eating disorder that causes them to eat non-food materials, such as soil and dirt, are more susceptible to the infection. Pica is more common in children than adults
• Eating unwashed fruits or vegetables
• Eating the liver of wild animals: This behavior has shown to increase the risk for developing Hepatic Capillariasis by a factor of about ten
• Children: Outdoor play activities and poor hygienic behavior

It is important to note that having a risk factor does not mean that one will get the condition. A risk factor increases one’s chances of getting a condition compared to an individual without the risk factors. Some risk factors are more important than others.

Also, not having a risk factor does not mean that an individual will not get the condition. It is always important to discuss the effect of risk factors with your healthcare provider.

What are the Causes of Hepatic Capillariasis? (Etiology)

Hepatic Capillariasis is caused by infection with nematodes belonging primarily to the species Capillaria hepatica (or Calodium hepaticum), a parasitic roundworm. The infection develops after humans ingest C. hepatica eggs that are usually shed in the feces by infected animals (foxes, monkeys, prairie dogs, rodents, etc.).

• Humans ingest eggs by accidentally consuming soil containing the eggs. It may occur from unwashed hands and/or by consuming food products that are grown on contaminated soil. Eating the liver of an infected animal can also cause infection
• After the eggs are ingested, the eggs hatch inside of the small intestine and then migrate towards the liver through the portal-hepatic system where they mature
  • This system normally carries nutrients from food to the liver via the blood vessels. Once inside the liver, female worms lay more eggs and then die-off
  • The eggs do not hatch until they are removed from the liver and excreted through feces. These then develop and embryonate in the soil
• It is possible for C. hepatica eggs to be transmitted from human to human, but only by ingesting soil contaminated with infected human feces

What are the Signs and Symptoms of Hepatic Capillariasis?

If an individual is infected with only one Capillaria hepatica worm, there may be no significant signs and symptoms noted. But, if there are multiple infecting worms, including several female worms that lay eggs, then a host of symptoms may be observed.

In such cases, the signs and symptoms of Hepatic Capillariasis may include the following:

• Fever
• Anemia: The signs and symptoms of anemia include fatigue, pale skin, easily getting tired on minor physical activity, and a low level of red blood cells in blood
• Hypereosinophilia, which is a large increase of eosinophils in blood. Eosinophils are a type of white blood cells (WBCs) that the body uses to fight infections and parasites
• Hepatomegaly, or enlargement of the liver
• Hepatitis: It is the inflammation of liver that can result in poor liver function. Some of the signs and symptoms of hepatitis include:
  • Loss of appetite
  • Nausea and vomiting
  • Diarrhea
  • Dark-colored urine
  • Pale feces
  • Stomach pain
  • Jaundice, or the yellowing of skin and eyes

How is Hepatic Capillariasis Diagnosed?

The diagnosis of Hepatic Capillariasis is made through the following tests and exams:

• A complete physical examination and review of one’s medical and/or recent travel history
• Assessment of the presenting signs and symptoms
• Blood tests that may include:
  • Complete blood count (CBC)
  • Liver function test
• Microscopic examination of stool sample; although, it is not an effective method in diagnosing the condition
• Imaging scans of the abdomen
• Fine needle aspiration (FNA) biopsy of the liver: A smaller number of liver cells are taken to be analyzed in the lab
• Liver biopsy: A tissue biopsy is performed and sent to a laboratory for a pathological examination. A pathologist examines the biopsy under a microscope. After putting together clinical findings, special studies on tissues (if needed) and with microscope findings, the pathologist arrives at a definitive diagnosis. Examination of the biopsy under a microscope by a pathologist is considered to be gold standard in arriving at a conclusive diagnosis

Note: In some cases, only an autopsy (post-mortem) may help establish Hepatic Capillariasis.

Many clinical conditions may have similar signs and symptoms. Your healthcare provider may perform additional tests to rule out other clinical conditions to arrive at a definitive diagnosis.

What are the possible Complications of Hepatic Capillariasis?

If Hepatic Capillariasis is not treated in a timely fashion, then severe liver damage that impairs the liver’s ability to function normally may occur. The complications of liver damage may include:

• Severe anemia
• Hepatomegaly or enlargement of the liver
• Hepatitis or liver inflammation

Severe complications may cause the liver function to completely fail, even resulting in death.

How is Hepatic Capillariasis Treated?

The treatment measures for Hepatic Capillariasis, a rare infection, may include the following: 

• Administration of anti-parasitic medications to help kill the parasites
• Steroids to help control liver inflammation
• Treating any underlying conditions such as pica: Some treatments for pica include mild aversion therapy (associating pica with negative consequences and normal eating habits with rewards) and use of medications

How can Hepatic Capillariasis be Prevented?

The preventative measures for Hepatic Capillariasis may include:

• Practicing good hygiene and disposing of fecal matter properly
• Washing hands with warm water and soap after working with or touching soil, especially before handling food
• Washing any fruits or vegetables before consumption, to ensure that they are free of dirt and soil
• Cooking the liver of wild animals thoroughly before consumption
• Seeking treatment after a diagnosis of pica
• Not feeding pets undercooked or raw meat (especially liver) from wild animals, which may cause pets to become infected and possibly spread the parasite to humans 

What is the Prognosis of Hepatic Capillariasis? (Outcomes/Resolutions)

• The prognosis of Hepatic Capillariasis is generally positive with suitable treatment. Individuals usually recover completely with early diagnosis and adequate treatment
• Development of severe complications, such as hepatitis and liver failure, can result in fatalities in the absence of suitable treatment

Additional and Relevant Useful Information for Hepatic Capillariasis:

• Adult C. hepatica can vary in length based on gender. Males are typically 24-37 mm long and 0.04 to 0.08 mm in diameter. Females generally grow to be larger than males, with an average length of 53-78 mm and a diameter of around 0.19 mm
• Females lay eggs in clusters and these eggs are protected by the host’s tissue. The females typically live for up to 59 days, while males live only about 40 days

Please visit our Digestive Health Center for more physician-approved health information:

https://www.dovemed.com/healthy-living/digestive-center/