Asymptomatic Sexually Transmitted Diseases: the Case for Screening

Background: The United States has the highest prevalence of sexually transmitted diseases in the developed world. Control strategies should address the most frequent reasons why curable sexually transmitted diseases are not treated.

Methods: We approached 1,631 persons ages 18-29 in various sites and offered them screening for gonorrhea and chlamydial infection and surveys regarding past genitourinary symptoms. For those with past symptoms we abstracted medical records or conducted additional interviews. From these data we estimated the total number of persons who had gonorrhea or chlamydial infections in the previous year, the proportion treated, and the primary reasons for nontreatment.

Results: The prevalence of gonorrhea was 2.3% and that of chlamydial infection was 10.1%. We estimate that 45 and 77% of all cases of gonorrhea and chlamydial infection, respectively, were never symptomatic and that 86 and 95% of untreated cases of gonorrhea and chlamydial infection, respectively, were untreated because they were never symptomatic. The remaining 14 and 5% of untreated cases of gonorrhea and chlamydia, respectively, were not treated because persons did not receive medical care for symptoms.

Conclusions: The primary reason that gonorrhea and chlamydial infections are untreated is that infected persons never have symptoms. The most effective method to control these sexually transmitted diseases is routine screening at high-volume sites.