To date, a limited number of studies have been conducted in an effort to assess the burden of CT in entire communities. A Baltimore study estimated the prevalence of CT infection to be 3% in a sample of 728 untreated adults between the ages of 18 and 35 years.28
Another study of approximately 14,322 young adults 18–26 years of age recruited from the Wave III of the National Longitudinal Study of Adolescent Health estimated CT prevalence to be approximately 4.2%; female gender, black race, and Southern residence were identified as risk factors for CT infection.29
To our knowledge, this study is among few that have explored CT prevalence and risk/protective factors using NHANES data23
and the first to explore gender and age disparities among sexually active adults.
Our study was consistent with the idea that young adults who are <25 years of age are disproportionately affected by CT infection. Besides race/ethnicity, marital status, and unprotected sex in the past month, other demographic, socioeconomic, and behavioral characteristics known to influence STI acquisition appear to be less important in explaining CT prevalence or inequalities according to age group. In the current study, self-reported use of cigarettes, binge alcohol drinking, and use of recreational drugs in the recent past were not significantly associated with CT infection among sexually active adults. An unexpected finding was the negative relationship between unprotected sex in the past month and CT infection among males in the stratified analysis. The limited sample size and, consequently, the wide CIs around the CT prevalence estimates may explain such a finding, which is contrary to expectation.
Past research has correlated the use of alcohol, especially binge drinking, and recreational drugs (methamphetamines, cocaine, and marijuana) with risky sexual behaviors leading to the acquisition of HIV and other STIs.30
This relationship has been documented in homosexual men, adolescents, heterosexual men and women, and psychiatric patients.30
In our analyses, such lifestyle factors were not associated with CT prevalence. This counterintuitive finding might be explained by cross-sectional design and exposure definition. Clearly, a temporal relationship cannot be established between use of substances and prevalent CT. Moreover, recent experiences with cigarettes, alcohol, and recreational drugs may not be entirely relevant to CT acquisition. Patterns of substance use preceding the event that led to CT infection are likely more salient but are difficult to ascertain in a cross-sectional design. Consistent with our findings, O'Leary et al.30
report that alcohol and drug use disorders may not account for the excess risk of STIs in the Southern region of the United States.
Unprotected sex is a modifiable risk factor for CT, and the increased prevalence of CT among non-Hispanic blacks is of public health concern. For instance, CT infection can ultimately lead to infertility, necessitating specialized and relatively expensive treatments, such as in vitro fertilization.31
These treatments may not be accessible to socioeconomically disadvantaged populations, of which large proportions are ethnic minorities. In sum, although the burden of CT infection and its associated health sequelae may be elevated among ethnic minorities, these same populations often have less access to healthcare services that can potentially alleviate the health consequences of a CT infection.
Our findings should be interpreted cautiously and in light of several limitations. First, the cross-sectional design precludes our ability to establish a temporal association between behavioral risk factors and CT infection. The available data identify prevalent rather than incident cases of CT. Therefore, risk characteristics may be correlates of CT incidence, duration, or both. Second, measurement error is an issue, especially for self-reported exposure data. Third, secondary analyses were performed and refined exposure measures. Finally, sample size did not permit stratification for the exploration of interactions among exposure, gender, and age groups.