Sexually Transmitted Disease Surveillance 1993

Division of STD/HIV Prevention 

December 1994

U.S. Department of Health and Human Services 
Public Health Service 
Centers for Disease Control and Prevention 
National Center for Prevention Services 
Division of STD/HIV Prevention 
Surveillance and Information Systems Branch 
Atlanta, Georgia 30333

                         Copyright Information 

All material contained in this report is in the public domain and may be
used and reprinted without special permission; citation to source,
however, is appreciated.

                           Suggested Citation

Division of STD/HIV Prevention. Sexually Transmitted Disease
Surveillance, 1993.  U.S. Department of Health and Human Services, Public
Health Service.  Atlanta: Centers for Disease Control and Prevention,
December 1994.

Copies can be obtained from Information Services, National Center for
Prevention Services, Centers for Disease Control and Prevention, 1600
Clifton Road, Mailstop E-06, Atlanta, Georgia 30333.

                                
                                Chlamydia
                                    
Infections due to Chlamydia trachomatis are among the most prevalent of all
sexually transmitted diseases. In women these infections often result in
serious reproductive tract complications, such as pelvic inflammatory
disease, infertility, and ectopic pregnancy.  In addition, infected
pregnant women can infect their babies during delivery.  However,
surveillance of chlamydial infection is incomplete in many areas of the
country.  A combination of factors limit the documentation of the incidence
and prevalence of genital chlamydial infection:  enforcement of public
health laws requiring that health care providers and laboratories report
cases to local health authorities; large numbers of asymptomatic persons
who can be identified only through screening; limited resources to support
screening activities; and incompletely developed information management
infrastructures for collecting, maintaining, and analyzing morbidity data.
Thus, for most areas, the number of reported chlamydia cases reported to
CDC by state health departments reflects the degree of local interest in
chlamydia as a public health problem and initial attempts to resolve
reporting limitations rather than true disease burden or trends. In 1993,
46 states reported chlamydial infections to CDC (Table_3).

     --   From 1984 through 1992 reported rates of chlamydia increased
          dramatically, from 3.2 cases per 100,000 population to 178.3
          (Figure_1); in 1993, the rate decreased slightly to 167.9. 
          Trends continue to primarily reflect increased screening,
          recognition of asymptomatic infection (mainly in women), and
          improved reporting capacity rather than true trends in disease
          incidence.

     --   Rates of chlamydia were highest in the West and the Midwest,
          where substantial resources have been committed for organized
          screening programs (e.g., in family planning clinics)
          (Figure_2 and Figure_3). In the areas where these
          screening programs are in place, chlamydia rates far exceed
          gonorrhea rates.

     --   Between 1992 and 1993 rates of chlamydia in large cities with
          >200,000 population decreased slightly from 290.2 cases per
          100,000 population to 272.3 (Figure_4, Table_6).

     --   Reported rates of chlamydia for women far exceed those for men
          (Figure_5, Table_4, Table_5, Table_7, and
          Table_8). This is mainly due to increased detection of
          asymptomatic infection in women through screening. The low rates
          in men suggest that many of the sex partners of women with
          chlamydia are not diagnosed or reported.

     --   Additional information on chlamydia screening programs in women
          and chlamydia in adolescents and minorities can be found in the
          Special Focus Profiles section.


Figure_1. Chlamydia - Reported rates: United States, 1984 1993    
Figure_2. Chlamydia - Rates by state: United States, 1993    
Figure_3. Chlamydia - Rates by region: United States, 1984-1993    
Figure_4. Chlamydia - Rates in U.S. cities of >200,000 population,
              1984-1993
Figure_5. Chlamydia - Rates by gender: United States, 1984-1993    

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