National Overview of Sexually Transmitted Diseases (STDs), 2008

Organized collaboration among interested, committed public and private organizations and communities is the key to reducing STDs and their related health burdens. As noted in the report of the Institute of Medicine, The Hidden Epidemic: Confronting Sexually Transmitted Diseases¹ surveillance is a key component of our efforts to prevent and control these diseases.

This overview summarizes national surveillance data on the three notifiable diseases for which there are federally-funded control programs: chlamydia, gonorrhea, and syphilis. Several observations for 2008 are worthy of note.

Chlamydia

In 2008, 1,210,523 cases of sexually transmitted Chlamydia trachomatis infection were reported to CDC (Table 1). This is the largest number of cases ever reported to CDC for any condition. This case count corresponds to a rate of 401.3 cases per 100,000 population, an increase of 9.2% compared with the rate in 2007. Rates of reported chlamydial infections among women have been increasing annually since the late 1980s when public programs for screening and treatment of women were first established to avert pelvic inflammatory disease (PID) and related complications. In 2008, the chlamydia rate in black men was 12 times higher than that in white men; the chlamydia rate in black women was eight times higher than that in white women.

The continued increase in chlamydia case reports in 2008 most likely represents a continued increase in screening for this infection, more sensitive tests, and more complete national reporting but it may also reflect a true increase in morbidity.

In 2008, the overall rate of chlamydial infection in the United States among women (583.8 cases per 100,000 females) was almost three times the rate among men (211.1 cases per 100,000 males), reflecting the large number of women screened for this disease (Tables 4 and 5). However, with the increased availability of urine testing, men are increasingly being tested for chlamydial infection. From 2004 through 2008, the chlamydia rate in men increased by 45% (compared with a 21.5% increase in women over this period).

Data from multiple sources on prevalence of chlamydial infection in defined populations have been useful in monitoring disease burden and guiding chlamydia screening programs.

In 2008, the median state-specific chlamydia test positivity among women 15 to 24 years of age who were screened at selected family planning clinics in all 50 states, the District of Columbia, Puerto Rico, and the Virgin Islands was 7.4% (range: 3.1% to 15.0%) (Figures 9 and 10).

At selected prenatal clinics in 22 states, Puerto Rico, and the Virgin Islands the median state-specific chlamydia positivity was 7.9% (range: 1.8% to 19.2%) (Figure B).

The prevalence of infection is greater among economically-disadvantaged women 16 to 24 years of age who entered the National Job Training Program in 2008 from 39 states, the District of Columbia, and Puerto Rico. The median state-specific prevalence was 12.8% (range: 5.4% to 20.8%) (Figure K). Among men entering the program in 2008 from 48 states, the District of Columbia, and Puerto Rico the median state-specific chlamydia prevalence was 7.0% (range: 0.8% to 14.4%) (Figure L).

Gonorrhea

Following a 74% decline in the rate of reported gonorrhea from 1975 to 1997, overall gonorrhea rates have plateaued over the past eleven years. In 2008, 336,742 cases of gonorrhea were reported in the United States, corresponding to a rate of 111.6 cases per 100,000 population, decreased from the rate in 2007 of 118.9 cases (Figure 13 and Table 1).

As in previous years, in 2008 the South had the highest gonorrhea rate among the four regions of the country (Table 13). Although the gonorrhea rate in the South declined for many years, it increased by 11% between 2005 and 2006 and has continued at that slightly elevated plateau through 2008. The rate in the West decreased slightly in 2007 and again in 2008 after a 29% increase between 2003 and 2006. While rates decreased in the Northeast and Midwest from 2007 to 2008, they have remained relatively stable over the past 10 years (Figure 15).

From 1996 to 2008 the rate of gonorrhea has been similar in men and women (Figure 14). In 2008 the gonorrhea rate in women was 119.4 per 100,000 population compared to a rate of 103.0 per 100,000 population in men (Figure 14). As with chlamydia, gonorrhea rates in women are highest in the 15 to 24 year age group. In men, they are highest in the 20 to 24 year age group (Figure 18). In 2008, the gonorrhea rate in black men was 28 times higher than that in white men; the gonorrhea rate in black women was 16 times higher than that in white women.

As with chlamydia in 2008, data on gonorrhea prevalence in defined populations were available from several sources. These data showed a continuing high burden of disease in adolescents and young adults in parts of the United States.

In 2008, the median state-specific gonorrhea test positivity among 15- to 24-year-old women screened in selected family planning clinics in 43 states, the District of Columbia, Puerto Rico, and the Virgin Islands was 0.9% (range: 0.0% to 3.8%) (Figure 23). In 2008, the median state-specific gonorrhea test positivity among 15- to 24-year-old women screened in selected prenatal clinics in 20 states, Puerto Rico, and the Virgin Islands was 1.0% (range: 0.0% to 5.0%) (Figure D).

For 16- to 24-year-old women entering the National Job Training Program in 37 states, the District of Columbia, and Puerto Rico in 2008, the median state-specific gonorrhea prevalence was 2.7% (range: 0.0% to 5.0%) (Figure M).

Among men entering the program from 34 states, the District of Columbia, and Puerto Rico, the median state-specific gonorrhea prevalence was 0.8% (range: 0.0% to 2.8%) (Figure N).

Among women entering juvenile corrections facilities the median gonorrhea positivity was 3.6% (range: 0.0% to 19.0%); the median gonorrhea positivity for men entering juvenile corrections facilities was 0.9% (range: 0.0% to 4.4%).

Among MSM, including men who have sex with both women and men, attending eight STD clinics, the median clinic urethral gonorrhea positivity was 8.0% (range: 4.0% to 12.0%).

Syphilis

The rate of primary and secondary (P&S) syphilis reported in the United States decreased during the 1990s and in 2000 was the lowest since reporting began in 1941. The low rate of syphilis and the concentration of the majority of syphilis cases in a small number of geographic areas led to the development of the National Plan to Eliminate Syphilis, which was announced by the Surgeon General in 1999 and updated in 2006.² The rate of P&S syphilis in the United States declined 89.7% between 1990 and 2000. However, the rate of P&S syphilis has increased each year since 2001, mostly in men, but also in women for the past four years. In 2008, 13,500 cases of P&S syphilis were reported to CDC. This is the highest number of cases since 1995 and corresponds to a rate of 4.5 cases per 100,000 population, an 18% increase from 2007. Since 2004, the rate of P&S syphilis has increased 67%. After 14 years of decline, the rate of congenital syphilis increased in 2006 and 2007. There were 431 cases of congenital syphilis reported in 2008, the same number reported in 2007.

Although wide disparities exist in the rates of STDs among racial and ethnic groups, there has been a reduction in these differences for syphilis over the past ten years. The P&S syphilis rate for 2008 in blacks was eight times the rate in whites, which is substantially lower than the disparity observed in 1999, when the rate among blacks was 29 times greater than that among whites (Table 34B). However, since 2003, increases in syphilis among blacks have been higher than increases among whites, reversing some of the gains made in this health disparity. In 2008, increases were observed among both black men (28.0 cases per 100,000 population, up from 22.9 in 2007) and black women (7.6 cases per 100,000 population, up from 5.5 in 2007). Much smaller increases were observed among white men (4.0 cases per 100,000 population, up from 3.7 in 2007) and white women (0.5 per 100,000 population, up from 0.4 per 100,000 in 2007).

While syphilis elimination efforts² initially focused on minority populations in general, increases in syphilis among MSM of all races and ethnicities since 2001 and more recent increases among women and blacks highlight the importance of continually reassessing and refining surveillance, prevention, and control strategies.

¹ Institute of Medicine. The Hidden Epidemic: Confronting Sexually Transmitted Diseases, Committee on Prevention and Control of Sexually Transmitted Diseases, National Academy Press, Washington, DC, 1997.

² Division of STD Prevention. The National Plan to Eliminate Syphilis from the United States. National Center for HIV/AIDS, Viral Hepatitis, STD, and TB Prevention, Centers for Disease Control and Prevention, 2006.