title: Misclassification of the stages of syphilis: implications for surveillance.
abstract: OBJECTIVE
  Syphilis cases were reviewed to see if reported stages met the Centers for Disease Control and Prevention case definition. Classification was excellent for primary and secondary and good for late latent, but half of early latent and unknown duration were misclassified. New surveillance definitions are suggested, comments requested.
  
  
  BACKGROUND
  Uncertainty when staging latent syphilis should lead clinicians to call it late latent (requires more treatment) and disease investigators to call it early latent (priority for partner investigation). Accurate surveillance requires consistent case definitions.
  
  
  OBJECTIVE
  Assess validity of reported syphilis stages.
  
  
  METHODS
  Record reviews in 6 jurisdictions to determine if reported cases met the Centers for Disease Control and Prevention case definitions.
  
  
  RESULTS
  Nine hundred seventy-three records from 6 jurisdictions in 2002 showed excellent agreement for reported primary (94.0%) and secondary (95.4%), good agreement for late latent (80.2%), and poor agreement for early latent (48.4%) and unknown duration (49.7%). Unknown duration (age < or =35 and nontreponemal test titer > or =32) was often misinterpreted to mean "not known." Early latent (within the past year, documented: seroconversion, fourfold titer increase, symptoms, or contact with an independently documented early syphilis case) was often misinterpreted to include patients with risky behavior, young age, or high nontreponemal test titers.
  
  
  CONCLUSIONS
  The unknown duration stage should be dropped. Surveillance of latent syphilis would be more consistent if cases were reported as having high or low titers on nontreponemal test. Alternative approaches are solicited from readers.
authors.affiliation: Division of STD Prevention, National Center for HIV, STD, and TB Prevention, Centers for Disease Control and Prevention, Atlanta, Georgia 30333, USA. tap1@cdc.gov
authors.forename: Thomas A
authors.initials: TA
authors.lastname: Peterman
authors.forename: Richard H
authors.initials: RH
authors.lastname: Kahn
authors.forename: Carol A
authors.initials: CA
authors.lastname: Ciesielski
authors.forename: Elizabeth
authors.initials: E
authors.lastname: Ortiz-Rios
authors.forename: Bruce W
authors.initials: BW
authors.lastname: Furness
authors.forename: Susan
authors.initials: S
authors.lastname: Blank
authors.forename: Julia A
authors.initials: JA
authors.lastname: Schillinger
authors.forename: Robert A
authors.initials: RA
authors.lastname: Gunn
authors.forename: Melanie
authors.initials: M
authors.lastname: Taylor
authors.forename: Stuart M
authors.initials: SM
authors.lastname: Berman
mesh_terms: D000328:Adult; D002487:Centers for Disease Control and Prevention, U.S.; D005260:Female; D006801:Humans; D008297:Male; D008485:Medical Audit; D008499:Medical Records; D017063:Outcome Assessment, Health Care; D010401:Penicillin G Benzathine / Q000008:administration & dosage; D011159:Population Surveillance; D011647:Puerto Rico / Q000453:epidemiology; D012189:Retrospective Studies; D013588:Syphilis Serodiagnosis / Q000592:standards* / Q000706:statistics & numerical data; D013592:Syphilis, Latent / Q000097:blood / Q000145:classification / Q000453:epidemiology* / Q000517:prevention & control*; D014481:United States / Q000453:epidemiology
chemical_list: D010401:Penicillin G Benzathine
references.citation: Sex Transm Dis. 2000 Jul;27(6):305-10
references.pmid: 10907903
references.citation: Sex Transm Dis. 2004 Jan;31(1):20-5
references.pmid: 14695954
references.citation: Am J Public Health. 1991 Oct;81(10):1259-62
references.pmid: 1928522
references.citation: Ann Intern Med. 1986 Mar;104(3):368-76
references.pmid: 3511822
references.citation: Sex Transm Dis. 2001 Mar;28(3):158-65
references.pmid: 11289198
references.citation: Sex Transm Dis. 1997 Oct;24(9):511-8
references.pmid: 9339968
references.citation: Am J Public Health. 1990 Jul;80(7):853-7
references.pmid: 2356911
references.citation: MMWR Morb Mortal Wkly Rep. 2003 Dec 19;52(50):1229-32
references.pmid: 14681596
references.citation: Ann Intern Med. 1994 Jul 15;121(2):94-100
references.pmid: 7912483
references.citation: N Engl J Med. 1997 Jul 31;337(5):307-14
references.pmid: 9235493
references.citation: Int J STD AIDS. 2004 Feb;15(2):73-88
references.pmid: 15006068
references.citation: Sex Transm Dis. 1990 Oct-Dec;17(4):163-8
references.pmid: 2264004
references.citation: Sex Transm Dis. 1999 Apr;26(4):201-7
references.pmid: 10225586
references.citation: Sex Transm Dis. 2001 Sep;28(9):497-503
references.pmid: 11518865
references.citation: Sex Transm Dis. 1997 Apr;24(4):185-200
references.pmid: 9101629
references.citation: Ann Emerg Med. 1993 Aug;22(8):1286-90
references.pmid: 8333629
references.citation: Sex Transm Dis. 2002 Aug;29(8):486-90
references.pmid: 12172535
references.citation: Sex Transm Dis. 2002 May;29(5):277-84
references.pmid: 11984444