National Overview of Sexually Transmitted Diseases (STDs), 2011

All Americans should have the opportunity to make choices that lead to health and wellness. Working together, interested, committed public and private organizations, communities, and individuals can take action to prevent sexually transmitted diseases (STDs) and their related health burdens. In addition to federal, state, and local public support for STD prevention, local community leaders can promote STD prevention education. Health providers can assess their patients’ risks and talk to them about testing. Parents can better educate their children about STDs and sexual health. Individuals can use condoms consistently and correctly, and openly discuss ways to protect their health with partners and providers. As noted in the Institute of Medicine report, The Hidden Epidemic: Confronting Sexually Transmitted Diseases,¹ surveillance is a key component of all our efforts to prevent and control these diseases.

This overview summarizes national surveillance data for 2011 on the three notifiable diseases for which there are federally funded control programs: chlamydia, gonorrhea, and syphilis. Several observations for 2011 are worthy of note.

Chlamydia

In 2011, a total of 1,412,791 cases of Chlamydia trachomatis infection were reported to the Centers for Disease Control and Prevention (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 457.6 cases per 100,000 population, an increase of 8.0% compared with the rate in 2010. 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.

The continued increase in chlamydia case reports in 2011 most likely represents a continued increase in screening for this usually asymptomatic infection, expanded use of more sensitive tests, and more complete national reporting, but it also may reflect a true increase in morbidity.

In 2011, the overall rate of chlamydial infection in the United States among women (648.9 cases per 100,000 females) was over two and a half times the rate among men (256.9 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. During 2007–2011, the chlamydia rate in men increased 36.2%, compared with a 20.2% increase in women during this period. Rates also varied among different racial and ethnic minority populations. For example, in 2011, the chlamydia rate in blacks was over seven times the rate in whites.

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

In 2011, the median state-specific chlamydia test positivity was 8.3% (range: 3.8% to 15.9%) among women aged 15–24 years who were screened at selected family planning clinics in all 50 states, the District of Columbia, Puerto Rico, and the Virgin Islands (Figures 13 and 14).

At selected prenatal clinics in 15 states, Puerto Rico, and the Virgin Islands, the median state-specific chlamydia positivity among women aged 15–24 years was 7.7% (range: 2.8% to 16.3%) (Figure B).

The prevalence of infection was greater among young economically disadvantaged women aged 16–24 years who entered the National Job Training Program (NJTP) in 2011 in 46 states, the District of Columbia, and Puerto Rico. The median state-specific prevalence was 10.3% (range: 4.1% to 18.7%) (Figure K). Among men entering the program in 2011 in 48 states, the District of Columbia, and Puerto Rico, the median state-specific chlamydia prevalence was 8.0% (range: 2.7% to 13.0%) (Figure L).

Among adolescent females aged 12–18 years entering selected juvenile corrections facilities, overall chlamydia positivity was 15.7%. Among adolescent males of the same age entering selected juvenile corrections facilities, overall chlamydia positivity was 7.4% (Figure BB).

Gonorrhea

Following a 74% decline in the rate of reported gonorrhea during 1975–1997, overall gonorrhea rates plateaued for 10 years; it decreased during 2006–2009 to the lowest rate since national reporting began and then increased 2.1% between 2009 and 2010. In 2011 there was another 4.0% increase with a total of 321,849 cases of gonorrhea reported in the United States, corresponding to a rate of 104.2 cases per 100,000 population (Figure 16, Table 1).

In 2011, as in previous years, the South had the highest gonorrhea rate among the four regions of the country (Table 14). While rates in 2011 increased in all four regions, the rate in the South remained more than twice the rate in the West (Figure 18).

During 1997–2006, gonorrhea rates in men and women were similar. Recently, the rates in women have been somewhat higher than rates in men (Figure 17). In 2011, the gonorrhea rate in women was 108.9 cases per 100,000 population compared with a rate of 98.7 in men. As with chlamydia, gonorrhea rates in women were highest among those aged 15–24 years. In men, they were highest among those aged 20–24 years (Figure 21). In 2011, the gonorrhea rate in blacks was 17 times the rate in whites. As with chlamydia, data on gonorrhea prevalence in defined populations were available from several sources in 2011. These data showed a continuing high burden of disease in some adolescents and young adults in parts of the United States.

Antimicrobial resistance remains an important consideration in the treatment of gonorrhea. With increased resistance to the fluoroquinolones and the declining susceptibility of cefixime, dual therapy with ceftriaxone and either azithromycin or doxycycline is now the only CDC recommended treatment for gonorrhea.² Continued monitoring of susceptibility patterns to these antibiotics is critical. No isolates with decreased susceptibility to ceftriaxone were seen in 2011 in CDC’s sentinel surveillance system, the Gonococcal Isolate Surveillance Project (GISP).

Syphilis

The rate of primary and secondary (P&S) syphilis reported in the United States decreased during the 1990s, and in 2000, it was the lowest since reporting began in 1941. The low rate of syphilis and the concentration of most syphilis cases in a small number of geographic areas led to the development of the National Plan to Eliminate Syphilis from the United States, which was announced by the Surgeon General in 1999 and updated in 2006.³ The overall rate of P&S syphilis in the United States declined 89.7% during 1990–2000, then increased each year from 2001 through 2009. In 2010, the overall rate decreased for the first time in 10 years; in 2011 this rate remained unchanged. Between 2010 and 2011, the rate decreased 9.1% in women but increased slightly, 3.8%, in men. In 2011, a total of 13,970 cases of P&S syphilis were reported to CDC, approximately 200 more than were reported in 2010. Approximately 72% of cases were in MSM.

After 14 years of decline, the number of reported cases of congenital syphilis reached an historic low of 339 cases in 2005. The number of cases increased from 2006–2008 but has since decreased with 360 cases reported in 2011, a 19% decrease since 2008.

Although wide disparities exist in the rates of STDs among racial and ethnic groups, these disparities have decreased for syphilis over the past 10 years. In 2011, the P&S syphilis rate among blacks was seven times the rate among whites, which is substantially lower than the disparity observed in 1999, when the rate among blacks was 24 times the rate among whites. In some subgroups, however, these disparities remain much higher. The 2011 rate among black men aged 15–19 years was 16 times the rate for white men of that age. The 2011, rate for black women aged 15–19 years was 30 times the rate for white women of the same age.

While efforts to eliminate syphilis have focused on racial and ethnic minority populations, the syphilis rates among all MSM have continued to increase since 2001, especially among young MSM.^4,5 Although some decreases were observed this year among blacks, syphilis rates remain disproportionately high among black men and women. These findings highlight the importance of continually reassessing and refining surveillance, prevention, and control strategies to eliminate syphilis.

1 Eng TR, Butler WT, editors; Institute of Medicine (US). The hidden epidemic: confronting sexually transmitted diseases. Washington (DC): National Academy Press; 1997. p 43.

2 Centers for Disease Control and Prevention. Update to CDC’s sexually transmitted diseases treatment guidelines, 2010. Oral cephalosporins no longer a recommended treatment for gonococcal infection. CDC’s MMWR Morb Mortal Wkly Rep. 2012;61(31):590-594.

3 Centers for Disease Control and Prevention. The national plan to eliminate syphilis from the United States. Atlanta: U.S. Department of Health and Human Services; 2006.

4 Su JR, Beltrami JF, Zaidi AA, Weinstock HS. Primary and secondary syphilis among black and Hispanic men who have sex with men: case report data from 27 states. Ann Intern Med. 2011;155 (3);145-151.

5 Heffelfinger JD, Swint EB, Berman SM, Weinstock HS. Trends in primary and secondary syphilis among men who have sex with men in the United States. Am J Pub Health. 2007;97(6):1076-1083.