Fascioliasis is a parasitic disease that primarily strikes livestock animals like sheep and cattle. It can appear in many parts of the world, but it’s generally more common in South America, parts of Asia, and Africa. People can also catch fascioliasis, and when they do, it is potentially more dangerous than it is for most kinds of livestock. The parasites, which are also called liver flukes, mature into worms that enter the body through contaminated food and attack the liver and bile ducts.
Once an animal is infected with fascioliasis, it will pass eggs in its feces. If this feces is released anywhere near water, there is a chance for the parasite to spread. They enter the bodies of certain water snails, where they mature. Once they reach a certain age, they exit the snails and attach themselves to underwater vegetation. Animals eat the vegetation, and they enter the bodies of these animals, where they generally mature further into relatively large worms that live in the bile ducts.
People normally catch the disease more often in situations where livestock live in the same general areas where food is grown. Most humans catch it from underwater food plants like watercress. Infection can potentially be avoided by cooking these plants fully before eating them. In some areas, eating these plants raw is relatively customary, and fascioliasis in humans is more common in those areas.
While the worms are in the process of maturing and making their way to a person’s bile ducts, he or she will generally experience vomiting and other severe gastrointestinal symptoms. Once the worms reach their full size, which can take three or four months, many of these symptoms will lessen, but people may begin to develop signs related to liver damage. Over time, fascioliasis can cause cirrhosis to develop, and symptoms are generally much worse in people than they are in animals. This is partly because the parasites are fairly large, and many animal species can handle large parasites much more easily than humans can.
Treatment of fascioliasis is usually relatively easy and involves the ingestion of a medication called triclabendazole. In cases where that doesn’t work or isn’t available, some doctors may also prescribe a medication called bithionol. Both medications are known to work fairly well, but they aren’t necessarily widely available. In many cases, the hard part about treating fascioliasis is recognizing it. In many parts of the world, infection is generally rare, so doctors may never consider fascioliasis as a possibility, which means they may not perform the correct diagnostic tests to discover it.