Comparative geographic concentrations of 4 sexually transmitted infections

Am J Public Health. 2005 Feb;95(2):324-30. doi: 10.2105/AJPH.2003.029413.


Objectives: We measured and compared the concentration of primary and secondary syphilis, gonorrhea, chlamydial infection, and genital herpes in a large county with urban, suburban, and rural settings.

Methods: We geocoded sexually transmitted infections reported to King County, Washington health department in 2000-2001 to census tract of residence. We used a model-based approach to measure concentration with Lorenz curves and Gini coefficients.

Results: Syphilis exhibited the highest level of concentration (estimated Gini coefficient = 0.68, 95% confidence interval [CI] = 0.64, 0.78), followed by gonorrhea (estimated Gini coefficient=0.57; 95% CI=0.54, 0.60), chlamydial infection (estimated Gini coefficient = 0.45; 95% CI = 0.40, 0.43), and herpes (estimated Gini coefficient=0.26; 95% CI=0.22, 0.29).

Conclusions: Geographically targeted interventions may be most appropriate for syphilis and gonorrhea. For less-concentrated infections, control strategies must reach a wider portion of the population.

Publication types

  • Comparative Study
  • Research Support, Non-U.S. Gov't
  • Research Support, U.S. Gov't, P.H.S.

MeSH terms

  • Censuses
  • Chlamydia Infections / epidemiology
  • Disease Notification*
  • Female
  • Geography
  • Gonorrhea / epidemiology
  • Herpes Genitalis / epidemiology
  • Humans
  • Male
  • Public Health Informatics
  • Sexually Transmitted Diseases / epidemiology*
  • Syphilis / epidemiology
  • Washington / epidemiology