title: Sarcocystis nesbitti infection in human skeletal muscle: possible transmission from snakes.
abstract: Sarcocystis nesbitti is an intracellular protozoan parasite found as sarcocysts within muscle fibers of intermediate hosts (monkey and baboon). The definitive host is suspected to be the snake. We report two cases from a larger cohort of 89 patients who had fever, headache, and generalized myalgia after a trip to Pangkor Island, Malaysia. Sarcocysts were detected in skeletal muscle biopsy specimens by light and electron microscopy from these two patients. DNA sequencing based on the 18S ribosomal DNA region identified the Sarcocystis species as S. nesbitti. We also identified S. nesbitti sequences in the stools of a snake (Naja naja). Phylogenetic analysis showed that these sequences form a cluster with most of the other known Sarcocystis species for which the snake is a definitive host. We believe these two patients were likely to have symptomatic acute muscular sarcocystosis after S. nesbitti infection that may have originated from snakes.
authors.affiliation: Departments of Parasitology, Medicine, and Pathology, Faculty of Medicine, University of Malaya, Kuala Lumpur, Malaysia.
authors.forename: Yee Ling
authors.initials: YL
authors.lastname: Lau
authors.forename: Phooi Yee
authors.initials: PY
authors.lastname: Chang
authors.forename: Chong Tin
authors.initials: CT
authors.lastname: Tan
authors.forename: Mun Yik
authors.initials: MY
authors.lastname: Fong
authors.forename: Rohela
authors.initials: R
authors.lastname: Mahmud
authors.forename: Kum Thong
authors.initials: KT
authors.lastname: Wong
mesh_terms: D000818:Animals; D016054:DNA, Protozoan / Q000235:genetics; D006801:Humans; D008854:Microscopy, Electron; D018482:Muscle, Skeletal / Q000469:parasitology*; D010802:Phylogeny; D012337:RNA, Ribosomal, 18S / Q000235:genetics; D012522:Sarcocystis / Q000469:parasitology*; D012523:Sarcocystosis / Q000469:parasitology / Q000635:transmission*; D017422:Sequence Analysis, DNA; D012911:Snakes / Q000469:parasitology*
chemical_list: D016054:DNA, Protozoan; D012337:RNA, Ribosomal, 18S