Paragonimus Infestation
Paragonimus is a parasitic fluke, most often associated with lung infections (paragonimiasis) in Southeast Asia. The Asian fluke species, Paragonimus westermani, is acquired through consumption of undercooked freshwater crustaceans. A related species, Paragonimus kellicotti, has rarely caused infections in North America. Recently, a series of nine paragonimiasis cases associated with consumption of crustaceans found in Missouri rivers, was described by Washington University, St. Louis (Emerging Infectious Diseases, vol 18(8) 2012). Two more cases of Paragonimus kellicotti infections have been diagnosed in Kansas City since August 2012.
Locally acquired Paragonimus kellicotti infestations are most common in young men who become infected with the organism following consumption of raw crayfish while camping or on a river float trip. Infections have been associated with crayfish found in the Current, Huzzah, Meramac, Jacks Fork, and Missouri Rivers. Incubation period for onset of signs or symptoms ranges from 2-12 weeks. Following ingestion, the parasite penetrates the intestinal wall, then migrates through the diaphragm to the pleural cavity and into the lungs. Eggs are deposited into lung tissue, usually within fibrous cysts that develop around the adult worm. Extrapulmonary sites including liver, lymph node, skin, spinal cord and brain may also be infected.
Common clinical findings in these cases include cough, hemoptysis, weight loss, fever and pleural effusions. The majority of patients have significant eosinophilia (>15%) and abnormal chest radiographs which may include nodules and pericardial effusions. Examination of sputum, bronchoscopy, pleural fluid, and stool specimens for the parasite is specific for the diagnosis, but very low yield (
