Paragonimus westermani, also known as the lung fluke, is a parasitic flatworm that can infect humans and animals, causing a disease called paragonimiasis. The infection is acquired by eating raw or undercooked crustaceans, such as crabs and crayfish, that are infected with this parasite. Paragonimiasis can be present in two forms: the pulmonary, and extrapulmonary forms.
People with the pulmonary form of paragonimiasis present with fever, night sweats, productive cough, hemoptysis, and pleural effusions. The extrapulmonary manifestation of paragonimiasis depends on the affected organs. In cerebral paragonimiasis, there is headache, vomiting, and seizures. Abdominal paragonimiasis there is abdominal pain, hematochezia, and nausea and vomiting.