Pleuropulmonary Infection by Paragonimus westermani in the United States: A Clinicopathologic Analysis of Four Cases with Identification of a Unique Risk Factor.
Jennifer M Boland, Laszlo T Vaszar, Jeffrey L Jones, Patricia Wilkins, Michael A Rovzar, Thomas V Colby, Kevin O Leslie, Henry D Tazelaar. Mayo Clinic, Rochester, MN; Mayo Clinic, Scottsdale, AZ; Centers for Disease Control and Prevention, Atlanta, GA; Mission Regional Medical Center, Mission Viejo, CA
Background: Infections caused by parasites in the genus Paragonimus are a rare cause of pleuropulmonary disease in the United States (US), typically acquired by eating raw crayfish carrying the species P. kellicotti. The species P. westermani has only rarely been reported in the US. Due to its nonspecific presentation, the diagnosis relies on a history of ingestion and the pathologic review of biopsy material. We report four cases of pleuropulmonary disease caused by US-acquired P. westermani.
Design: We identified all cases of P. westermani pulmonary infection in the consultation files of the authors. We recorded the clinical history, risk factors and serologic diagnostic data, and reviewed histologic slides.
Results: Four cases (3 men and 1 woman, aged 20-66 years) were identified. Patients presented with pulmonary complaints and chest imaging abnormalities: cavitary infiltrates (2), lung mass (1), pleural effusion (1) and pneumothorax (1). Surgical biopsies showed marked eosinophilic infiltrates including eosinophilic pneumonia with organizing pneumonia in all cases. Granulomatous inflammation with geographic necrosis (3), vasculitis (3), and pleuritis (3) were also encountered. Paragonimus organisms/eggs were identified in 2 cases. Serologic studies were positive for P. westermani in 3 cases (2 ELISA and 1 immunoblot) and helped confirm the diagnosis in 2 cases lacking organisms or eggs. Three patients ate live crabs at sushi bars (including crabs in martinis, a previously unreported mechanism for infection). In one patient the source of infection was undetermined, although as a manager of a Japanese restaurant it is postulated that he ingested infected imported crabs.
Conclusions: Paragonimiasis should be considered in the differential diagnosis of patients with eosinophilic pleuropulmonary disease in the US. Although eosinophilic pneumonia was a consistent finding, the biopsy findings may be non-specific as the organisms and/or eggs are not always visualized. Unusual features include pleuritis, foci of geographic necrosis and granulomatous vasculitis. A history of ingestion and targeted serologies are key to the diagnosis.
Wednesday, March 2, 2011 9:30 AM
Poster Session V # 268, Wednesday Morning