Chlamydia is the Most Frequently Reported Bacterial Infectious Disease in the United States
The correct answer is C: Chlamydia. Chlamydia trachomatis infection is definitively the most commonly reported sexually transmitted bacterial infection in the United States, with over 4 million cases occurring annually 1.
Epidemiologic Evidence
Multiple authoritative sources confirm chlamydia's status as the most frequently reported bacterial infectious disease:
The U.S. Preventive Services Task Force explicitly states that "Chlamydia trachomatis infection is the most commonly reported sexually transmitted infection in the United States" 1
The CDC reported 929,462 chlamydial infections in 2004, with numbers increasing steadily over the preceding decade 1
More recent surveillance data confirms chlamydia remains the most frequently reported infectious disease overall, with the highest incidence among persons aged 15-25 years 1
Research studies consistently identify chlamydia as "the most common bacterial sexually transmitted disease in the United States" with an estimated 3-4 million new cases annually 2, 3, 4, 5
Comparison to Other Options
Why not the other choices:
Herpes simplex (Option A) is viral, not bacterial, and therefore is excluded by the question parameters 1
Gonorrhea (Option B) is substantially less common than chlamydia, with reported cases being only a fraction of chlamydia cases 1
Syphilis (Option D) has far lower incidence, with only 78 cases of chancroid (a related condition) reported in 2000 as an example of the relatively rare occurrence of non-chlamydial bacterial STDs 1
Clinical Significance
The high prevalence of chlamydia has important public health implications:
Most infections are asymptomatic in both men and women, sustaining community transmission 1
Untreated infections lead to serious sequelae including pelvic inflammatory disease, infertility, ectopic pregnancy, and chronic pelvic pain 1
The direct and indirect costs exceed $2.4 billion annually 1
Prevalence is highest (>10%) among sexually active adolescent females, particularly non-Hispanic Black females (13.5%) 1, 2