Human Paragonimiasis in North America following Ingestion of Raw Crayfish

Paragonimiasis (human infections with the lung fluke Paragonimus westermani) is an important public health problem in parts of Southeast Asia and China. Paragonamiasis has rarely been reported from North America as a zoonosis caused by Paragonimus kellicotti. Paragonimus species have complex life cycles that require 2 intermediate hosts, namely, snails and crustaceans (ie, crabs or crayfish). Humans acquire P. kellicotti when they consume infected raw crayfish. Humans with paragonimiasis usually present with fever and cough, which, together with the presentation of hemoptysis, can be misdiagnosed as tuberculosis. Only 7 autochthonous cases of paragonimiasis have been previously reported from North America. Our study describes 3 patients with proven or probable paragonimiasis with unusual clinical features who were seen at a single medical center during an 18-month period. These patients acquired their infections after consuming raw crayfish from rivers in Missouri. It is likely that other patients with paragonimiasis have been misdiagnosed and improperly treated. Physicians should consider the possibility that patients who present with cough, fever, hemoptysis, and eosinophilia may have paragonimiasis.