Sexually Transmitted Disease Surveillance 1995

Division of STD Prevention

September 1996

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

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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 Prevention. Sexually Transmitted Disease Surveillance,
1995. U.S. Department of Health and Human Services, Public Health Service.
Atlanta: Centers for Disease Control and Prevention, September 1996.

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Control and Prevention, 1600 Clifton Road, Mailstop E-06, Atlanta, Georgia
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                                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. Furthermore, chlamydia
facilitates HIV transmission. While surveillance of chlamydial infections
is improving, it remains incomplete in many areas of the country. A
combination of factors limits documentation of the incidence and prevalence
of genital chlamydial infection: large numbers of asymptomatic persons who
can be identified only through screening; limited resources to support
screening activities; variable compliance with public health laws and
regulations that require health care providers and laboratories to report
cases to local health authorities; and incompletely developed information
management systems for collecting, maintaining, and analyzing morbidity and
prevalence 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 reporting
limitations rather than true disease burden or trends.

--  In 1995, 477,638 chlamydial infections were reported to CDC from 49
    states (Table_3). This is the second consecutive year that reported
    cases of chlamydia exceeded reported cases of gonorrhea (392,848
    gonorrhea cases in 1995, Table_1).

--  From 1984 through 1995 reported rates of chlamydia increased
    dramatically, from 3.2 cases per 100,000 population to 182.2
    (Figure_1). Trends continue to reflect primarily increased
    screening, recognition of asymptomatic infection (mainly in women), and
    improved reporting capacity rather than true trends in disease
    incidence.

--  As in previous years, 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_3, Table_3). In the areas where these screening
    programs are in place, chlamydia rates far exceed gonorrhea rates. From
    1994 to 1995, reported chlamydia rates declined in the West (from 214.7
    cases per 100,000 population to 191.1), and in the Midwest (from 218.4
    to 206.4), but increased in the South and Northeast. 

--  Between 1994 and 1995 rates of chlamydia reported from large cities
    (>200,000 population) decreased 5% from 327.2 cases per 100,000
    population to 310.5 (Figure_4, Table_6).

--  Reported rates of chlamydia for women (290.3 per 100,000 population)
    exceed those for men (52.1 per 100,000 population) (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. In addition, men
    diagnosed as having non-gonococcal urethritis are treated, but
    frequently are not tested specifically for chlamydia. A large
    proportion of these men are infected with chlamydia, but they are not
    detected by surveillance systems based on laboratory reporting of
    positive chlamydia tests.

--  Additional information on chlamydia screening programs for women of
    reproductive age and chlamydia among adolescents and minority
    populations can be found in the Special Focus Profiles section.

Figure_1.  Chlamydia -- Reported rates: United States, 1984-1995
Figure_2.  Chlamydia -- Rates by state: United States, 1995
Figure_3.  Chlamydia -- Rates by region: United States, 1984-1995
Figure_4.  Chlamydia -- Rates in U.S. cities of >200,000 population,
               1984-1995
Figure_5.  Chlamydia -- Rates by gender: United States, 1984-1995

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