Parasitic Infections of the Liver

The liver is the second largest organ of the human body. Like other organs, it is also susceptible to diseases. Out of all the causes behind liver damage, one is due to parasitic infection. Parasites affecting the liver are collectively referred to as liver flukes. Liver infections caused by liver fluke parasites is a major concern in some parts of the world like Southeast Asia, Far East and Eastern Europe. Liver flukes that commonly cause infection are Clonorchis sinensis, Fasciola hepatica and Opisthorchis species. Discussed below are the parasitic infections caused by each one of them in detail.

Parasitic Liver Infections

Clonorchiasis
This infection is caused by Clonorchis sinensis or the Oriental liver fluke. The parasite affects the distal bile ducts of the biliary system. The main reason behind transmission of this parasite to the human body is intake of raw or undercooked fish. The infection can also lead to bile duct carcinoma which can further result into cirrhosis of the liver. Southeast Asian people are more prone to this infection as they consume a lot of raw and undercooked fish in the form of sushi, in their diet.

Symptoms

• Hepatomegaly
• Abdominal pain
• Fever
• Chills
• Diarrhea
• Anorexia

Chronic cases produce symptoms like chronic cholangitis along with cirrhosis, atrophy of liver parenchyma and portal hypertension. Many patients infected by this parasitic worm do not show any symptoms till the condition is aggravated causing permanent liver damage.

Treatment
Any person displaying the above symptoms should be taken to a doctor so that medical treatment can be immediately started before any major damage occurs in the body. The doctor prescribes diagnostic tests to confirm the infection after which, he prescribes broad spectrum anthelmintics to the patient which can control a wide range of parasites. In cases where flukes have turned into adults, medications are not sufficient. Hence, surgical procedures are carried out to remove the fluke from the body. In patients with suspected strongyloidiasis, empiric treatment is given to improve the condition of the patient.

Fasciolosis
Liver rot or fasciolosis is another commonly occurring parasitic liver disease. It is caused by two types of trematodes namely Fasciola hepatica and Fasciola gigantica. The first species is predominantly found in America and Europe, while both the species are found in Asia and Africa. These parasitic worms tend to concentrate in the bile ducts of the liver. Humans ingest this parasite through the intake of aquatic vegetables, which act as prime reservoirs for these parasites.

Symptoms

• Anemia
• Jaundice
• Urticaria
• Gastrointestinal disturbances
• Fever
• Abdominal pain
• Hepatomegaly and splenomegaly

Respiratory problems like cough, chest pain and dyspnoea can occur rarely. In chronic conditions, the patient may show inflammation and hyperplasia of the epithelium. Along with it, nausea, pruritis, epigastric pain, jaundice and fatty food intolerance can also occur. These clinical symptoms are associated with cholangitis, cholecystitis and cholelithiasis and are no different from other causes of these conditions.

Treatment
The treatment of fasciolosis is mostly done using anthelmintics. Doctors prescribe various medications from this category of drugs depending on the species causing the infection. Patients who have developed cholangitis along with fasciolosis are prescribed with additional medications like antibacterial antibiotics. Studies are being conducted to establish an Egyptian drug, made from myrrh, as a treatment option for parasitic infections like fasciolosis.

Opisthorchiasis
This parasitic disease of the liver is caused by Opisthorchis viverrini and Opisthorchis felineus. It is more prevalent amongst poor Asian people. In this region, raw cyprinid fish is the staple food, which is the primary host of these liver flukes. Once the parasite enters the human body, it establishes itself in the bile ducts, extrahepatic ducts and the gallbladder.

Symptoms

• Diarrhea
• Anorexia
• Fatigue
• Jaundice
• Mild fever
• Epigastric pain
• Pain in the upper right quadrant

These symptoms are produced when the infection is strong, such that around 10,000-30,000 eggs are found in 1 gm of feces during diagnosis. When the infection shows the presence of around 1000 eggs in 1 gm of feces, no symptoms are produced because the infection is minimal.

Treatment
During 1951-1968, doctors tried to use chloroquine for the treatment of this infection, but was proven unsuccessful. Later on, doctors started using anthelmintics like praziquantel for its treatment. Many new anthelmintic drugs are being studied in recent times for their efficacy in the treatment of liver fluke infections.

Educating people about maintaining good eating habits can help in the prevention of liver fluke infections because transmission of these parasitic worms basically takes place through intake of uncooked food. Early diagnosis and proper treatment can help a person to get over with this infection without much trouble.