Human Paragonimiasis in North America following Ingestion of Raw Crayfish

Abstract

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.

Paragonimiasis Acquired in the United States: Native and Nonnative Species

“…In the United States, P. kellicotti is found living in a broad range of mammalian hosts mainly in the midwestern and southern United States within the Mississippi River Basin. Most cases of autochthonous paragonimiasis in the United States caused by native P. kellicotti flukes are transmitted by the ingestion of raw or undercooked crayfish, the preferred crustacean intermediate hosts for P. kellicotti (1)(2)(3). The U.S. regional distribution of P. kellicotticaused paragonimiasis cases is depicted in Fig.…”

Red swamp crayfish: biology, ecology and invasion - an overview

“…Within Paragonimidae, species from Paragonimus, highly evolved parasites with a complex life cycle that involves at least three different hosts, i.e., snails, crustaceans, and mammals, are known to use crayfish species, including P. clarkii, as intermediate hosts (Sogandares-Bernal, 1965); the adults of Paragonimus reside and mate in the lungs of a variety of mammalian hosts, wild and domestic animals, as well as humans, causing a disease named paragonimiasis (Lane et al, 2009;Procop, 2009).…”

Serological Diagnosis of North American Paragonimiasis by Western Blot Using Paragonimus kellicotti Adult Worm Antigen

“…Previous case reports showed that months or years may pass between the onset of the illness and parasitological diagnosis. 3,4 Diagnosis was often delayed for many months after the onset of symptoms, and patients often failed therapeutic trials of antibiotics and/or steroids before proper diagnosis and treatment.…”