Background

Gonorrhea is the second most commonly-reported notifiable disease in the United States. Infections due to Neisseria gonorrhoeae, like those resulting from Chlamydia trachomatis, are a major cause of pelvic inflammatory disease (PID) in the United States. PID can lead to serious outcomes in women such as tubal infertility, ectopic pregnancy, and chronic pelvic pain. In addition, epidemiologic and biologic studies provide strong evidence that gonococcal infections facilitate the transmission of HIV infection.¹

From 1975 through 1997, the national gonorrhea rate declined 74% following implementation of the national gonorrhea control program in the mid-1970s (Table 1). Gonorrhea rates subsequently appeared to plateau for several years. However, in 2005, rates increased slightly from 2004 with 339,593 cases of gonorrhea reported in the United States (Figure 11 and Table 1). True increases or decreases may be masked by changes in screening practices (affected by concomitant testing for chlamydia and broader use of urine-based testing), use of diagnostic tests with differing test performance, and changes in reporting practices.²

For most areas, the number of gonorrhea cases reported to CDC is affected by many factors, in addition to the occurrence of the infection within the population. As with reporting of other STDs, reporting of gonorrhea cases to CDC is incomplete.³ In addition, reporting practices for gonococcal infections may have been biased towards reporting of infections in persons of minority race or ethnicity, who are more likely to attend public STD clinics.⁴ For such reasons, supplemental data on gonorrhea prevalence in persons screened in a variety of different settings are useful in assessing disease burden in selected populations.

Gonorrhea – United States

In 2005, 339,593 cases of gonorrhea were reported in the United States. The rate of reported gonorrhea in the United States was 115.6 cases per 100,000 population in 2005 (Figure 11 and Table 1), the first increase in gonorrhea since 1999.

Gonorrhea by Region

As in previous years, in 2005 the South had the highest gonorrhea rate among the four regions of the country. However, the gonorrhea rate in the South has declined by 17.6% from a rate of 174.6 per 100,000 population in 2001 to 143.9 in 2005. Rates in the Northeast have also declined 23.1% from 2001 to 2005 (from 97.2 to 74.7). In contrast, the gonorrhea rate in the West has increased by 35.4% from 60.2 cases per 100,000 population in 2001 to 81.5 in 2005. The rate in the Midwest (142.5 in 2001 and 139.1 in 2005) has shown minimal change since 2001. Of note, however, is that gonorrhea rates in both the Midwest and the South increased slightly (4.0% and 1.6% respectively) from 2004 to 2005 (Figure 13 and Table 12).

Gonorrhea by State

In 2005, only states and Puerto Rico had gonorrhea rates below the Healthy People 2010 (HP2010) national target of 19 cases per 100,000 population (Figure 14 and Table 11).⁵

Gonorrhea by Metropolitan Statistical Area (MSA)

The overall gonorrhea rate in the 50 most populous MSAs was 128.2 cases per 100,000 population in 2005. This is a 3.9% increase from the prior year. All of these MSAs had rates higher than the HP2010 target of 19 cases per 100,000 population (Table 16). In 2005, 59.6% of gonorrhea cases were reported by these MSAs. Similar to previous years, in 2005 the total gonorrhea rate among females in these MSAs (127.4) remained similar to that among males (128.4) (Tables 17 and 18).

Gonorrhea by County

In 2005, 1,303 (41.5%) of 3,140 counties in the United States had gonorrhea rates at or below the HP2010 national target of 19 cases per 100,000 population. Rates per 100,000 population were between 19 and 100 in 1,118 counties (35.6%), and greater than 100 in 719 counties (22.9%). The majority of counties with greater than 100 cases per 100,000 population were located in the South (Figure 15).

In 2005, 50% of reported gonorrhea cases occurred in just 66 counties or independent cities (Table 15).

Gonorrhea by Reporting Source

In 2005, 28.1% of gonorrhea cases were reported by STD clinics. This is a change from 2001, when 36.6% of gonorrhea cases were reported by STD clinics (Table A2). In 2005, similar to previous years, a higher proportion of male gonorrhea cases were reported from STD clinics than female cases (40.4% and 17.0% respectively) (Figure 16).

Gonorrhea by Region and Sex

From 2001 to 2005, gonorrhea rates among women increased 41.4% in the West, and decreased 23.0% in the Northeast and 15.0% in the South. Over the same time period, gonorrhea rates among men increased 30.7% in the West, and decreased 23.2% in the Northeast and 20.4% in the South (Tables 13 and 14). Rates among both women and men in the Midwest remained relatively unchanged over this time period.

Gonorrhea by Sex

Prior to 1996, rates of gonorrhea among men were higher than rates among women. For the fifth straight year, however, gonorrhea rates in women are slightly higher than in men (Figure 12). In 2005 the gonorrhea rate among women was 119.1 and the rate among men was 111.5 cases per 100,000 population (Tables 13 and 14).

Gonorrhea by Race/Ethnicity

Changes in gonorrhea rates from 2001 through 2005 differed by racial/ethnic group. Gonorrhea rates decreased by 17.8% during this time period for African Americans from 762.0 to 626.4 cases per 100,000 population. In contrast, rates in other racial/ethnic groups have increased. Since 2001, the gonorrhea rate among American Indian/Alaska Natives increased 28.4% (131.7 per 100,000 in 2005), whites increased 19.7% (35.2 per 100,000 in 2005), Hispanics increased 6.4% (74.8 per 100,000 in 2005), and Asian/Pacific Islanders increased 5.3% (25.9 per 100,000 in 2005) (Figure 17 and Table 20B).

In 2005, the gonorrhea rate among African Americans was 18 times greater than the rate for whites. This is a decrease from 2001 when there was a 26-fold difference in rates. Gonorrhea rates were 3.7 times greater among American Indian/Alaska Natives, and 2.1 times greater among Hispanics than among whites in 2005.

Gonorrhea by Age and Sex

In 2005, gonorrhea rates continued to be highest among adolescents and young adults. The overall gonorrhea rate was highest for 20- to 24-year-olds (506.8), which is over 4 times higher than the national gonorrhea rate. Among females in 2005, 15- to 19- and 20- to 24-year-olds had the highest rates of gonorrhea (624.7 and 581.2, respectively); among males, 20-to 24-year-olds had the highest rate (436.8) (Figure 18 and Table 19).

Although the gonorrhea rate among 15- to 19-year-olds decreased in recent years, in 2005 this rate increased 3.9%. Similar slight increases were seen among 20- to 24-year-olds and 25- to 29-year-olds (3.0% and 4.3%) (Table 19). Increases over this time period were similar among males 15-to 19-years, 20- to 24-years, and 25- to 29-years (4.4%, 2.8%, and 3.8% respectively) and among females 15- to 19-years, 20- to 24-years, and 25- to 29-years (3.6%, 3.2%, and 4.8%, respectively) (Figures 19 and 20, and Table 19).

Gonorrhea by Race/Ethnicity and Sex

From 2001 to 2005 the overall rate in African-American men decreased 19.4% from 826.8 per 100,000 population to 666.0. Decreases were seen in all age groups of African-American men over this time period. However, the overall rate in white males increased 18.9% from 23.3 per 100,000 population in 2001 to 27.7 in 2005. Rates among American Indian/ Alaska Native men increased 44.1%, Asian/Pacific Islander men increased 13.7%, and Hispanic men increased 2.6% (Table 20B).

From 2001 to 2005 the overall rate among African-American women decreased 16.1% from 703.3 per 100,000 population to 590.4. Decreases were noted in 15- to 19-year-old African-American women (18.3% from 2001 through 2005).

However, 15- to 19-year-old African-American women still have the highest gonorrhea rate of any group (2,814.0 per 100,000 population). Rates among white women increased 20.4% from 35.3 per 100,000 population in 2001 to 42.5 in 2005. Increases were also seen among American Indian/Alaska Native women (21.4%) and Hispanic women (10.0%) over this time period (Table 20B). The rate among Asian/Pacific Islander women remained essentially unchanged (1.9% decrease).

Gonorrhea Prevalence Monitoring Projects

Gonorrhea test positivity data are available from a variety of settings. Screening criteria and practices may vary by state.

Family Planning Clinics

In 2005, the median state-specific gonorrhea test positivity among 15- to 24-year-old women screened in selected family planning clinics in 41 states, Puerto Rico, the District of Columbia, and the Virgin Islands was 1.0% (range 0.0% to 3.8%) (Figure 21). Median gonorrhea positivity in family planning clinics has shown minimal change in recent years (1.0% in 2001).

Prenatal Clinics

For women attending selected prenatal clinics in 20 states, Puerto Rico, and the Virgin Islands, the median positivity was 0.9% (range 0.0% to 3.2%) (Figure F). Median gonorrhea positivity in prenatal clinics has shown minimal change in recent years (0.9% in 2001).

National Job Training Program

For 16- to 24-year-old women entering the National Job Training Program in 32 states and the District of Columbia in 2005, the median state-specific gonorrhea prevalence was 2.4% (range 0.0% to 6.6%) in 2005 (Figure M). Among men entering the program from 14 states in 2005, the median state-specific gonorrhea positivity was 2.2% (range 0.0% to 6.1%) (Figure N).

Juvenile Corrections

In 2005, the median positivity for gonorrhea in women entering 38 juvenile corrections facilities was 4.7% (range 0.9% to 14.2%), and in men entering 65 juvenile corrections facilities was 1.0% (range 0.0% to 19.0%) (Table CC).

Gonococcal Isolate Surveillance Project (GISP)

Antimicrobial resistance remains an important consideration in the treatment 6-10 of gonorrhea. Overall, 19.6 % of isolates collected in 2005 in 27 STD clinics by the Gonococcal Isolate Surveillance Project (GISP) were resistant to penicillin, tetracycline, or both, up from 15.9% in 2004 (Figure 23).

Quinolone-resistant N. Gonorrhoeae (QRNG)

Resistance to ciprofloxacin (a fluoroquinolone in the quinolone family of antimicrobials) was first identified in GISP sites in 1991. From 1991 through 1998, fewer than nine quinolone-resistant N. gonorrhoeae (QRNG) isolates were identified each year, and such isolates were identified in only a few GISP clinics. In 2000, similar to 1999, 19 (0.4%) quinolone-resistant GISP isolates were identified in seven GISP clinics. In 2001, 38 (0.7%) QRNG isolates were identified in six clinics; in 2002, 116 (2.2%) such isolates were identified in 13 clinics; in 2003, 270 (4.1%) were identified in 21 clinics; in 2004, 429 (6.8%) were identified in 24 clinics; and in 2005, 581 (9.4%) isolates were submitted and identified in 25 of the 27 clinics in GISP demonstrating resistance to ciprofloxacin (Figure 24).

QRNG by Region

In Honolulu, the prevalence of QRNG identified remains high but has slightly decreased from 2004. In 2005, 17 (19.3%) of 88 isolates submitted from Honolulu demonstrated ciprofloxacin-resistance, down from 21 (22.8%) of 92 isolates in 2004.

In California, increases in the number of isolates resistant to ciprofloxacin were identified in four of five GISP sites, while one site, Long Beach, experienced a slight decrease from 25% in 2004 to 23.5% in 2005. Whereas, in Los Angeles, 14.5% of isolates in 2005 were ciprofloxacin-resistant compared with 13.8% in 2004; in Orange County, 27.5% were resistant in 2005 compared to 20.5% in 2004; in San Diego, 26.2% were resistant in 2005 compared to 20.6% in 2004; and in San Francisco, 31.3% were resistant in 2005 compared to 24.3% in 2004.

Similarly in other West Coast sites, Portland, Denver, and Las Vegas experienced a substantial increase in prevalence of QRNG, whereas Seattle experienced a slight decrease. In Portland, the prevalence of QRNG doubled to 23.1% in 2005 from 11.5% in 2004; in Denver, to 10.9% in 2005 from 8.3% in 2004; and in Las Vegas, to 5.4% in 2005 from 2.4% in 2004. In Seattle the prevalence dropped to 11.6% in 2005 from 16.2% in 2004. The QRNG prevalence in Phoenix remained relatively stable.

In the South, increases in prevalence of QRNG occurred in Atlanta, Miami, Oklahoma City, and New Orleans. In Atlanta, QRNG resistance increased to 3.8% in 2005 from 0.9% in 2004; in Miami, to 9.1% in 2005 from 6.8% in 2004; in Oklahoma City, to 2.3% in 2005 from 1.3% in 2004; and in New Orleans, to 6.3% in 2005 from 1.6% in 2004. (Note: As a result of Hurricane Katrina, the 2005 prevalence for QRNG in New Orleans contains isolates only from January–May 2005.) In Greensboro, the prevalence was slightly down to 0.6% in 2005 from 0.8% in 2004; the prevalence in Dallas remained the same.

In the Midwest and Northeast, there were large increases in prevalence of QRNG seen in Baltimore, Chicago, Cincinnati, Cleveland, and Philadelphia. In Baltimore, prevalence increased to 3% in 2005 from 1% in 2004; in Chicago to 4.7% in 2005 from 2.3% in 2004; in Cincinnati to 1% in 2005 from 0.3% in 2004; in Cleveland to 2.8% in 2005 from 0.4% in 2004; and in Philadelphia, the prevalence quadrupled to 14.3% in 2005 from 3.3% in 2004. There was a slight decrease in QRNG prevalence in Minneapolis for 2005.

Sites that identified ciprofloxacin-resistant isolates for the first time in 2005 include Birmingham and Detroit. Only Albuquerque and Tripler did not identify QRNG isolates during 2005.

Overall, outside of Hawaii and California, 6.1% of isolates were ciprofloxacin-resistant in 2005, an increase from 3.6% in 2004.

Additional information on antimicrobial susceptibility data and treatment recommendations from state and local health departments may be found in the 2005 GISP report⁷ or the GISP website.

QRNG by Sexual Behavior

The number of QRNG isolates from men who have sex with men (MSM) continued to increase in 2005 to 387 (29% of all specimens from MSM). During the same time period, the number of these isolates from heterosexuals increased from 136 (2.9%) in 2004 to 183 (3.8%) in 2005 (Figure 25).

As a result of this continued high prevalence of quinolone-resistant N. gonorrhoeae in California, Hawaii, among MSM, and the increasing prevalence of QRNG in areas other than the West Coast, in 2006 CDC recommended that quinolones should not be used for infections in MSM or in those with a history of recent foreign travel or partners' travel, infections acquired in California or Hawaii, or infections acquired in other areas with increased QRNG prevalence.¹⁰

Other Antimicrobial Susceptibility Testing

To date, cephalosporin resistance has not been identified in GISP, and the proportion of GISP isolates demonstrating decreased susceptibility to ceftriaxone or cefixime has remained very low over time. In 2001, three GISP isolates with decreased susceptibility to cefixime were also found to be resistant to penicillin, tetracycline, and ciprofloxacin; such multi-drug resistance in combination with decreased susceptibility to cefixime had not previously been identified in the United States.¹¹ In 2004, two GISP isolates had decreased susceptibility to cefixime; one of those isolates demonstrated the same resistance pattern as the 2001 isolates described above. In 2005, no GISP isolates had decreased susceptibility to ceftriaxone or cefixime.

The proportion of GISP isolates demonstrating elevated minimum inhibitory concentrations (MICs) to azithromycin has been increasing since GISP began monitoring azithromycin susceptibility in 1992. In 1992, there were no isolates with azithromycin MIC ≥ 1.0 mg/ml but in 2004 there were 57 (0.9%) such isolates, and this has now tripled to 181 (2.9%) in 2005. However, caution is needed when interpreting this increase, as a change in the media used for antimicrobial susceptibility testing in 2005 may have contributed to the increase.

Gonorrhea Among Special Populations

Additional information about gonorrhea in racial and ethnic minority populations, adolescents, men who have sex with men, and other at risk populations can be found in the Special Focus Profiles.

Gonorrhea Summary

In summary, the national gonorrhea rate increased in 2005 for the first time since 1999. Gonorrhea rates have declined among African Americans, but increased in all other racial and ethnic groups since 2001. However, rates among African Americans remain markedly higher than among other racial and ethnic groups.

Gonorrhea has increased in the West for several years, and 2005 data now suggest that these increases may be appearing in the South and the Midwest as well. Rates among adolescent and young adults had been decreasing in recent years, but 2005 data now suggest possible increases in these populations.

In addition, 2005 GISP data has shown notable increases in QRNG prevalence, especially in the Midwest and Northeast regions where previously it had been lower. As a response to these observations, modifications were made in the 2006 CDC STD Treatment Guidelines.¹⁰ Also, elevated MICs for azithromycin have been observed but the significance of this is yet to be determined.

¹ Fleming DT, Wasserheit JN. From epidemiological synergy to public health policy and practice: the contribution of other sexually transmitted diseases to sexual transmission of HIV infection. Sex Transm Infect, 1999 Feb;75(1):3-17.

² Centers for Disease Control and Prevention. Gonorrhea – United States, 1998. MMWR 2000;49:538-42.

³ Sexually Transmitted Diseases in America: How Many Cases and At What Cost? Prepared for the Kaiser Family Foundation by: American Social Health Association, December 1998, ASHA: Research Triangle Park, NC, Kaiser Family Foundation: Menlo Park, CA 94025.

⁴ Fox KK, Whittington W, Levine WC, Moran JS, Zaidi AA, Nakashima AN. Gonorrhea in the United States, 1981–1996: demographic and geographic trends. Sexually Transmitted Diseases 1998;25(7):386-93.

⁵ U.S. Department of Health and Human Services. Healthy People 2010. 2nd ed. With Understanding and Improving Health and Objectives for Improving Health. 2 vols. Washington, DC: U.S. Government Printing Office, November 2000.

⁶ Centers for Disease Control and Prevention. Fluoroquinolone-resistance in Neisseria gonorrhoeae, Hawaii, 1999, and decreased susceptibility to azithromycin in N. gonorrhoeae, Missouri, 1999. MMWR 2000;49:833-837.

⁷ Centers for Disease Control and Prevention. Sexually Transmitted Disease Surveillance 2005 Supplement: Gonococcal Isolate Surveillance Project (GISP) Annual Report 2005. Atlanta, GA: U.S. Department of Health and Human Services (available first quarter 2007).

⁸ Centers for Disease Control and Prevention. Increases in fluoroquinolone-resistant Neisseria gonorrhoeae – Hawaii and California, 2001 MMWR 2002;51:1041-1044.

⁹ Centers for Disease Control and Prevention. Increases in fluoroquinolone-resistant Neisseria gonorrhoeae among men who have sex with men – United States, 2003, and revised recommendations for gonorrhea treatment, 2004. MMWR 2004;53:335-338.

¹⁰ Centers for Disease Control and Prevention. Sexually Transmitted Diseases Treatment Guidelines, 2006. MMWR, 2006;55(No. RR-11).

¹¹ Wang SA, Lee MV, Iverson CJ, Ohye RG, Whiticar PM, Hale JA, Trees DL, Knapp JS, Effler PV, Weinstock HS. Multi-drug resistant Neisseria gonorrhoeae with decreased susceptibility to cefixime, Hawaii, 2001. CID 2003;37:849-52.