Compared to older age groups, teenagers and young adults in the United States are at high risk of acquiring sexually transmitted diseases (STDs). Although the disparity in STD rates across age groups is well documented, changes in the degree of disparity in STD rates across age groups over time have not been examined in detail.
We examined age-, sex-, and race-specific incidence rates of syphilis and gonorrhea in the United States (excluding New York owing to incomplete age- and race-specific data) from 1981 to 2005. STD rates in younger age groups (ages 15–29 years) were compared to STD rates in older age groups (ages 40–54 years) for each year over the 25-year period. We used regression analyses to examine the trend in the age rate ratio (STD rate in the younger age group divided by STD rate in the older age group) over time, adjusting for autocorrelation.
The age disparity in syphilis and gonorrhea declined from 1981 to 2005. The estimated annual decline in the age rate ratio was 5.3% for syphilis and 2.0% for gonorrhea for all races overall (P <0.01). Overall, the age disparity in STD rates was more pronounced for females than males.
Future research is needed to clarify the main determinants of the relative decline in STD rates in younger persons and to inform programmatic responses to the changing age disparity in STD rates.
The age disparity in syphilis and gonorrhea rates declined from 1981 to 2005.
From the Division of STD Prevention, National Center for HIV, STD, and TB Prevention, Centers for Disease Control and Prevention, Atlanta, Georgia
The authors thank the Division of STD Prevention seminar participants for helpful comments and suggestions.
The findings and conclusions in this report are those of the authors and do not necessarily represent the views of the Centers for Disease Control and Prevention.
Correspondence: Harrell W. Chesson, PhD, Division of STD Prevention, National Center for HIV, STD, and TB Prevention, Centers for Disease Control and Prevention, Atlanta, GA. E-mail: firstname.lastname@example.org.
Received for publication July 9, 2007, and accepted October 17, 2007.