title: Molecular Typing of Treponema pallidum in Ocular Syphilis.
abstract: Syphilis can have many clinical manifestations, including eye involvement, or "ocular syphilis." In 2015, an increase in reported cases of ocular syphilis and potential case clusters raised concern for an oculotropic strain of Treponema pallidum, the infectious agent of syphilis. Molecular typing was used to examine strains found in cases of ocular syphilis in the United States.
  
  
  
  In 2015, after a clinical advisory issued by the Centers for Disease Control and Prevention, pretreatment clinical specimens from US patients with ocular syphilis were sent to a research laboratory for molecular analysis of T. pallidum DNA. Molecular typing was conducted on these specimens, and results were compared with samples collected from Seattle patients diagnosed with syphilis, but without ocular symptoms.
  
  
  
  Samples were typed from 18 patients with ocular syphilis and from 45 patients with syphilis, but without ocular symptoms. Clinical data were available for 14 ocular syphilis patients: most were men, human immunodeficiency virus-infected, and had early syphilis. At least 5 distinct strain types of Treponema pallidum were identified in these patients, and 9 types were identified in the Seattle nonocular patients. 14d/g was the most common type in both groups. An unusual strain type was detected in a small cluster of ocular syphilis patients in Seattle.
  
  
  
  Ocular syphilis is a serious sequela of syphilis. In this preliminary study, clear evidence of a predominant oculotropic strain causing ocular syphilis was not detected. Identification of cases and prompt treatment is critical in the management of ocular syphilis.
authors.affiliation: From the *Centers for Disease Control and Prevention, Atlanta, GA; †Department of Neurology, and ‡Department of Medicine (Infectious Diseases), University of Washington School of Medicine, Seattle, WA.
authors.forename: Sara
authors.initials: S
authors.lastname: Oliver
authors.forename: Sharon K
authors.initials: SK
authors.lastname: Sahi
authors.forename: Lauren C
authors.initials: LC
authors.lastname: Tantalo
authors.forename: Charmie
authors.initials: C
authors.lastname: Godornes
authors.forename: Robyn
authors.initials: R
authors.lastname: Neblett Fanfair
authors.forename: Lauri E
authors.initials: LE
authors.lastname: Markowitz
authors.forename: Sheila A
authors.initials: SA
authors.lastname: Lukehart
authors.forename: Christina M
authors.initials: CM
authors.lastname: Marra
mesh_terms: D000328:Adult; D015818:Eye Infections, Bacterial / Q000175:diagnosis* / Q000453:epidemiology / Q000382:microbiology / Q000473:pathology; D005260:Female; D015658:HIV Infections / Q000150:complications* / Q000821:virology; D006801:Humans; D008297:Male; D008875:Middle Aged; D058889:Molecular Typing; D009494:Neurosyphilis / Q000175:diagnosis* / Q000453:epidemiology / Q000382:microbiology / Q000473:pathology; D000072339:Sexual and Gender Minorities; D014210:Treponema pallidum / Q000145:classification* / Q000235:genetics; D014481:United States / Q000453:epidemiology; D055815:Young Adult