Paragonimiasis is a type of parasitic infection that usually results from eating raw or undercooked seafood, such as crabs and crayfish. Parasitic worms called flukes mature in the gastrointestinal tract of humans and eventually migrate to the lungs and other parts of the body. A person who contracts paragonimiasis may experience abdominal pain and nausea shortly after infection, and chest pain, tightness, and coughing up to six months later. Doctors can usually treat the condition with antiparasitic medications, though surgery may be necessary in severe cases.
The flukes that cause paragonimiasis are members of the Paragonimus genus, and most are found in semitropical regions of Southeast Asia, Latin America, and Africa. Eggs hatch in water and quickly invade host organisms, mainly crustaceans. When people catch and consume infected crustaceans without thoroughly cooking their food, immature flukes can attach to the walls of the stomach and small intestine. In a period of one to six months, adult flukes begin to invade the lungs, liver, kidneys, and other organs. New eggs are expelled in feces and sputum, introducing a new generation of flukes into the environment.
Some people who contract paragonimiasis do not experience any symptoms and the flukes eventually die within the body. Most individuals, however, suffer from a number of acute and chronic symptoms. In the early stages of infection, a person might have stomach pain, cramps, diarrhea, and nausea. A dry cough and a fever typically develop within about a week, and symptoms frequently return over the course of about six months. When flukes reach the lungs, an individual may experience chest tightness, shortness of breath, and a wet cough.
A doctor who suspects a parasitic infection can collect samples of blood, stool, and sputum for laboratory analysis. A complete blood count is performed to check for abnormally high levels of white blood cells, a telling sign of paragonimiasis. Microscopic inspection of stools and saliva may reveal the presence of actual fluke eggs. A doctor may also decide to take an x-ray of the chest to check for lesions on the lungs and nearby organs. Once a diagnosis has been confirmed, the physician can consider the best course of treatment.
Most cases of paragonimiasis can be cured with a series of oral antiparasitic drugs. If flukes have already formed lesions in the body, a patient may need to undergo surgery to have them removed. It is important for a patient to attend regular checkups with his or her physician following treatment to ensure the infection is completely eradicated. The doctor can also explain the importance of safe food preparation to avoid future infections.