Summary about Disease
Fascioliasis is a parasitic infection caused by the liver flukes Fasciola hepatica and, less commonly, *Fasciola gigantica*. These flukes primarily infect livestock, but humans can become infected by consuming raw or undercooked freshwater plants (especially watercress) contaminated with infective larvae (metacercariae). The flukes mature in the liver and bile ducts, causing inflammation, pain, and potential complications.
Symptoms
Symptoms of fascioliasis can vary depending on the stage of infection. The acute phase (early infection) may involve:
Fever
Abdominal pain (especially in the upper right quadrant)
Nausea and vomiting
Loss of appetite
Fatigue
Hives (urticaria)
Muscle aches The chronic phase (later infection) may involve:
Intermittent abdominal pain
Jaundice (yellowing of the skin and eyes)
Hepatomegaly (enlarged liver)
Anemia
Biliary obstruction (in severe cases)
Cholangitis
Causes
Fascioliasis is caused by infection with the liver flukes Fasciola hepatica or *Fasciola gigantica*. The life cycle of the fluke involves snails as intermediate hosts. Humans become infected by:
Eating raw or undercooked freshwater plants, such as watercress, that are contaminated with metacercariae (the infective larval stage).
Drinking water contaminated with metacercariae (less common).
Medicine Used
The primary medication used to treat fascioliasis is:
Triclabendazole: This is the drug of choice and is highly effective against both immature and mature flukes. In some cases, alternative medications may be considered, but triclabendazole is the preferred treatment.
Is Communicable
Fascioliasis is not directly communicable from person to person. Humans acquire the infection from contaminated environmental sources (primarily plants) rather than from other infected individuals.
Precautions
Avoid eating raw or undercooked freshwater plants, especially watercress, in areas where fascioliasis is endemic.
Wash freshwater plants thoroughly with potable water before consumption. Washing may help to reduce but may not completely eliminate the risk of infection.
Boil or cook freshwater plants to kill any metacercariae that may be present.
Ensure proper sanitation and wastewater treatment to prevent contamination of freshwater sources with fluke eggs.
Control fascioliasis in livestock through veterinary measures, including treatment with anthelmintic drugs.
Drink only safe or treated water, especially in endemic areas.
How long does an outbreak last?
The duration of a fascioliasis outbreak depends on the source of contamination and the effectiveness of control measures. Outbreaks linked to contaminated watercress, for example, may be relatively short-lived once the source is identified and removed. However, if the underlying environmental conditions that support the fluke life cycle (e.g., presence of snails and grazing livestock) persist, sporadic cases or smaller outbreaks may continue to occur over a longer period. Without any intervention, infection can persist for many years
How is it diagnosed?
Fascioliasis is diagnosed primarily through:
Microscopic examination of stool samples: Eggs of Fasciola hepatica or *Fasciola gigantica* can be detected in stool samples. Multiple samples may be required, as egg excretion can be intermittent.
Serological tests: Antibody detection tests (ELISA) are available and can be helpful, particularly in the early stages of infection before eggs are being shed.
Imaging studies: Ultrasound, CT scans, or MRI may be used to visualize the liver and bile ducts and identify abnormalities associated with fascioliasis.
Timeline of Symptoms
Incubation period: Symptoms typically appear weeks to months after ingestion of metacercariae.
Acute phase (weeks to months): Fever, abdominal pain, nausea, vomiting, fatigue, hives.
Chronic phase (months to years): Intermittent abdominal pain, jaundice, hepatomegaly, anemia, biliary obstruction. Note that the exact timeline can vary depending on the individual and the severity of the infection. Some people may experience a more rapid progression of symptoms, while others may have a more gradual onset.
Important Considerations
Fascioliasis is a neglected tropical disease, and awareness of the disease may be limited in some regions.
Diagnosis can be challenging, as the symptoms can be non-specific and mimic other conditions.
Early diagnosis and treatment are important to prevent complications.
Public health interventions, such as education about safe food handling practices and control of fascioliasis in livestock, are crucial for preventing and controlling the disease.
Resistance to triclabendazole has been reported in some areas.