Scrub Typhus Outbreak, Northern Thailand, 2006–2007
Figure 2. . . Maximum parsimony phylogenetic tree of Orientia tsutsugamushi based on partial 56-kDa type-specific antigen gene sequences, demonstrating the relationships among O. tsutsugamushi isolates from Thailand and strains causing scrub typhus in humans in Ban Pongyeang, Thailand, and reference (ref) strains. The tree was midpoint rooted. Bootstrap values >50% are labeled over branches (1,000 replicates). Isolates from Thailand are in boldface. The tree was generated by using heuristic search with random stepwise addition (10 replicates). Scale bar indicates nucleotide substitutions per site.