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.
A number of methods have been used for the detection of the presence of microsarcocysts in animals, but little information exists on the value between the various methods. This study therefore examined for Sarcocystis spp. using three different methods in 105 samples of skeletal muscle collected from goats slaughtered in an abattoir in Selangor, Malaysia from January to February 2014. Three methods were used, direct light microscopy of squashed fresh muscle tissues; histological examination of fixed, sectioned, and hematoxylin and eosin (H&E)-stained samples of muscle; and molecular identification by polymerase chain reaction (PCR). Of the 105 tissue samples, 55 (52.38 %) were positive by light microscopy (LM), 46 (43.8 %) by histology, and 95 (90.48 %) by PCR. Only 29 (27.6 %) and 5 (4.76 %) samples were positive and negative, respectively, by all three methods. The cysts were elongated to a spindle shape with a mean size of 393.30 × 81.6 μm and containing banana-shaped bradyzoites of size 12.32 × 2.08 μm. The wall of the cyst was radially striated with a thickness of 2.83 μm. Samples were tested for the presence of Sarcocystis-specific 18S rRNA and were identified as Sarcocystis capracanis. Of the three methods used, the PCR test appears to be the most useful method for the diagnosis of sarcocystosis especially for species identification.