Notes from the field: acute muscular sarcocystosis among returning travelers - Tioman Island, Malaysia, 2011.

GeoSentinel (the surveillance program of the International Society of Travel Medicine and CDC) has identified 32 cases of suspected acute muscular sarcocystosis in travelers returning from Tioman Island off the east coast of peninsular Malaysia. All the patients traveled to Tioman Island during the summer of 2011. Within days or weeks of returning home, all experienced fever and muscle pain, often severe and prolonged. All had peripheral eosinophilia, and most had elevated serum creatinine phosphokinase levels. Most were tested for acute trichinosis and toxoplasmosis by serology, and all of these tests were negative. Approximately half of the patients were identified in Germany; others were reported elsewhere in Europe, and in North America and Asia. Muscle biopsy from two patients demonstrated organisms consistent with sarcocystosis, one from a group of five ill travelers and one from a group of three.