Paragonimus

Paragonimus is a genus of lung flukes (trematodes) that infects the lungs of various mammals, including humans. The most common species is Paragonimus westermani. Infection with Paragonimus can lead to a disease known as paragonimiasis.

Life Cycle

The life cycle of Paragonimus involves several hosts. The adult flukes reside in the lungs of the definitive host, where they produce eggs. These eggs are coughed up and swallowed, then passed in the feces. If these eggs reach fresh water, they hatch into miracidia, which infect a suitable snail intermediate host. Within the snail, the miracidia develop into sporocysts, rediae, and then cercariae. The cercariae leave the snail and encyst in the tissues of a second intermediate host, typically a crustacean such as a crab or crayfish. When the definitive host consumes the infected crustacean, the metacercariae excyst in the intestine, penetrate the intestinal wall, and migrate to the lungs, where they mature into adult flukes.

Symptoms and Treatment

Infection with Paragonimus can cause a range of symptoms, including cough, chest pain, and fever. In some cases, the infection can spread to other parts of the body, such as the brain or abdominal cavity, leading to more serious symptoms. Diagnosis is typically made by identifying Paragonimus eggs in a patient's sputum or feces. Treatment usually involves the use of antiparasitic drugs, such as praziquantel or triclabendazole.

Epidemiology

Paragonimus is found worldwide, but is most common in East Asia and South America. It is estimated that more than 20 million people are infected with Paragonimus worldwide.

See Also

• Paragonimiasis
• Trematode
• Praziquantel
• Triclabendazole

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  Paragonimus westermani egg
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  Paragonimus westermani adult