Comparative geographic concentrations of 4 sexually transmitted infections.
OBJECTIVE
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.
Kerani
Roxanne P
RP
Public Health-Seattle and King County, Harborview Medical Center, #359777, 325 9th Avenue, Seattle, WA 98104, USA. rkerani@u.washington.edu
Handcock
Mark S
MS
Handsfield
H Hunter
HH
Holmes
King K
KK
D019352:Censuses; D002690:Chlamydia Infections / Q000453:epidemiology; D018563:Disease Notification; D005260:Female; D005843:Geography; D006069:Gonorrhea / Q000453:epidemiology; D006558:Herpes Genitalis / Q000453:epidemiology; D006801:Humans; D008297:Male; D040442:Public Health Informatics; D012749:Sexually Transmitted Diseases / Q000453:epidemiology*; D013587:Syphilis / Q000453:epidemiology; D014861:Washington / Q000453:epidemiology