Outbreak of human infection with Sarcocystis nesbitti, Malaysia, 2012

Abstract

An outbreak of fever associated with myalgia and myositis occurred in 2012 among 89 of 92 college students and teachers who visited Pangkor Island, Malaysia. The Sarcocystis nesbitti 18S rRNA gene and sarcocysts were obtained from muscle tissues of 2 students. Our findings indicate emergence of S. nesbitti infections in humans in Malaysia.

Keywords: Malaysia; Pangkor Island; Sarcocystis nesbitti; emerging infectious disease; fever; human infection; myalgia; myositis; parasites; protozoa.

Figure 1

A) Sarcocysts isolated from persons infected with Sarcocystis nesbetti, Pangkor Island, Malaysia, 2012. Intact human sarcocyst (length 190 µm) with thin cyst wall (arrow) from homogenized temporalis tissue inoculated into a U937 monocytic cell culture (original magnification ×200, scale bar = 20 µm). B) Intramuscular sarcocyst enclosed by a thin smooth cyst wall (arrow) without any protrusions. Maximum cyst wall thickness is ≈0.5 µm (hematoxylin and eosin stained, original magnification ×40, scale bar = 10 µm).

Figure 2

Neighbor-joining phylogenetic tree of Sarcocystis spp. 18S rRNA sequences. Sarcocystis nesbitti strains isolated in this study are indicated in boldface. Numbers at nodes indicate bootstrap values (%) for 1,000 replicates. Bootstrap values <70% are not shown. Scale bar indicates nucleotide substitutions per site.