Gonorrhea

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 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 (Figure 13). For the past 12 years, however, gonorrhea rates appear to have reached a plateau (Figure 14 and Table 1).

Increases in gonorrhea rates in eight western states from 2000 to 2005 have been described among a wide variety of populations in the affected states.² Increases in quinolone resistant Neisseria gonorrhoeae (QRNG) in 2007 led to changes in national guidelines that now limit the recommended treatment of gonorrhea to a single class of drugs, the cephalosporins.³ The combination of increases in gonorrhea morbidity in some populations with increases in resistance and decreased treatment options have reinforced the need for better understanding of the epidemiology of gonorrhea.

Although gonorrhea case reporting is useful for monitoring trends in gonorrhea, true increases or decreases in disease burden 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.⁴

For most states, 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.⁵ For these 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 2008, 336,742 cases of gonorrhea were reported in the United States, a rate of 111.6 cases per 100,000 population (Figure 13 and Table 1), reflecting a small decrease of 5.4% since 2007. Gonorrhea rates have remained relatively stable over the past 12 years.

Gonorrhea by Region

As in previous years, in 2008 the South had the highest gonorrhea rate among the four regions of the country (152.4 cases per 100,000 population). Rates in the South and Midwest have remained substantially higher than rates in the Northeast and West. Rates in all regions over the last year have shown little change (Figure 15 and Table 13).

Gonorrhea by State

In 2008, gonorrhea rates per 100,000 population by state ranged from 6.0 cases in Vermont to 256.8 cases in Mississippi (Figure 16, Table 12).

Gonorrhea by Metropolitan Statistical Area (MSA)

The overall gonorrhea rate in the 50 most populous MSAs was 121.5 cases per 100,000 population in 2008. This is decreased from the rate of 128.3 cases per 100,000 population in 2007. In 2008, 58.7% of gonorrhea cases were reported by these MSAs (Table 16). Similar to previous years, in 2008 the total gonorrhea rate among females in these MSAs (123.5) remained similar to that among males (118.8) (Tables 17 and 18).

Gonorrhea by County

In 2008, 1,305 (41.6%) of 3,141 counties in the United States had gonorrhea rates at or below the HP2010 national target of 19 cases per 100,000 population. (See the Appendix [Interpreting STD Surveillance Data section] for an explanation of HP2010 target setting methods.) Rates per 100,000 population were between 19 and 100 in 1,136 counties (36.2%), and greater than 100 in 700 counties (22.3%). The majority of counties with greater than 100 cases per 100,000 population were located in the South (Figure 17).

In 2008, 50% of reported gonorrhea cases occurred in just 71 counties or independent cities (Table 19).

Gonorrhea by Sex

Prior to 1996, rates of gonorrhea among men were higher than rates among women. For the eighth consecutive year, however, gonorrhea rates among women and men were similar (Figure 14 ). In 2008, the gonorrhea rate among women was 119.4 and the rate among men was 103.0 cases per 100,000 population (Tables 14 and 15).

Gonorrhea by Age

In 2008, gonorrhea rates continued to be highest among adolescents and young adults. Among females in 2008, 15- to 19- and 20- to 24-year-old women had the highest rates of gonorrhea (636.8 and 608.6, respectively). Among males, the rate was highest in those 20 to 24 years of age (433.6) (Figure 18 and Table 20).

From 2004 to 2008, increases in gonorrhea rates were seen among 15- to 24- year olds (7.4% among those 15 to 19 years of age and 5.3% among those 20 to 24 years of age) and decreases in rate were seen among those 25 to 44 (3.8% among those 25 to 29 years of age, 4.7% among those 30 to 34 years of age, 17.6% among those 35 to 39 years of age, and 17.3% among those 40-44 years of age) (Table 20).

From 2004 to 2008, similar trends were seen by sex; increases occurred in gonorrhea rates in females and males between 15 and 19 years of age (5.6% and 11.2%, respectively) and in females and males between 20 and 24 years of age (8.1% and 2.0%, respectively). During the same time period, decreases in gonorrhea rates were seen in females and males between 35 and 39 years of age (10.2% and 21.1%, respectively) and in females and males between 40 and 44 years of age (11.9% and 19.6%, respectively) (Figures 19 and 20, and Table 20).

Gonorrhea by Race/Ethnicity

In 2008, gonorrhea rates remained highest among blacks (625.0 cases per 100,000 population, Figure 21 and Table 21B). Similar to recent years, the rate among blacks was 20.2 times greater than the rate among whites (31.0 cases per 100,000 population). Gonorrhea rates were 3.6 times greater among American Indian/Alaska Natives (110.2 cases per 100,000 population), and 2.2 times greater among Hispanics (66.8 cases per 100,000 population) than among whites in 2008. Rates among whites were 1.6 times higher than those among Asian/Pacific Islanders (20.0 cases per 100,000 population) in 2008 (Figure 21 ).

Between 2004 and 2008, gonorrhea rates showed no marked changes for any racial or ethnic group. (Figure 21 and Table 21B). Additional information on gonorrhea among minority populations can be found in the Special Focus Profiles.

Gonorrhea by Region and Sex

Between 2004 and 2008, gonorrhea rates among women increased 1.4% in the Midwest and 14.4% in the South. During the same time period, rates among women decreased 13.3% in the Northeast and 14.0% in the West (Table 14).

Between 2004 and 2008, gonorrhea rates among men decreased in the West, Northeast, and Midwest (15.3%, 8.9%, and 8.1%, respectively). During the same time period, rates among men in the South remained essentially the same (Table 15).

Gonorrhea by Race/Ethnicity and Sex

From 2004 to 2008, overall gonorrhea rates decreased among white, black, American Indian/Alaska Native, and Hispanic men (by 12.6%, 5.0%, 4.2%, and 2.6%, respectively). During the same time period, rates increased only among Asian/Pacific Islander males (1.6%) (Table 21B).

From 2004 to 2008 overall gonorrhea rates decreased among Asian/Pacific Islander, American Indian/Alaska Native, Hispanic, and white women (by 7.1%, 6.1%, 3.3%, and 3.0% respectively). During the same time period, rates increased only among black women (5.9%) (Table 21B).

In 2008, 15- to 19-year-old black women again had the highest gonorrhea rate of any group (2,934.6 per 100,000 population), closely followed by 20- to 24 year-old black women (2,777.0), and 20- to 24-year-old black men (2,340.3).

Gonorrhea by Reporting Source

In 2008, 23.0% of gonorrhea cases were reported by STD clinics (Table A2). This is a decrease from 2004, when 30.0% of gonorrhea cases were reported by STD clinics. In 2008, a higher proportion of male gonorrhea cases were reported from STD clinics than female cases (32.3% and 15.2% respectively) (Figure 22 and Table A2).

Prevalence Monitoring

Gonorrhea test positivity data are primarily available from family planning clinic settings. Screening criteria and practices may vary by state and over time.

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).

Gonococcal Isolate Surveillance Project (GISP)

Antimicrobial resistance remains an important consideration in the treatment of gonorrhea.^6-13 In 1986, GISP, a national sentinel surveillance system, was established to monitor trends in antimicrobial susceptibilities of strains of Neisseria gonorrhoeae in the United States among selected STD clinics in approximately 25–30 GISP sentinel sites and 4-5 regional laboratories (Figure 24).¹³

Information on the GISP antimicrobial susceptibility criteria used is in the GISP section of the Appendix (Interpreting STD Surveillance Data).

Susceptibility to Ceftriaxone

Susceptibility testing for ceftriaxone began in 1987. Figure 25 shows the distribution of Minimum Inhibitory Concentrations (MICs) to ceftriaxone among GISP isolates from 2004 to 2008. There was a small increase in the proportion of GISP isolates with MICs of 0.06 µg/ml since 2006 but no increases were observed at higher MIC values.

There have been four isolates with decreased susceptibility to ceftriaxone in GISP; all four had MICs of 0.5 µg/ml. Their locations and years were: San Diego-1987, Cincinnati-1992 and 1993, and Philadelphia-1997. No isolates with decreased susceptibility to ceftriaxone were seen in 2008.

Susceptibility to Azithromycin

GISP began monitoring azithromycin susceptibility in 1992. Figure 26 shows the distribution of MICs to azithromycin among GISP isolates from 2004 to 2008. The proportion of GISP isolates at MICs of 0.5 µg/ml and 1.0 µg/ml for azithromycin has been increasing since 2004.

Susceptibility to Spectinomycin

All isolates were susceptible to spectinomycin in 2008. There have been five spectinomycin-resistant isolates in GISP; their locations and years were: St. Louis-1988, Honolulu-1989, San Francisco-1989, Long Beach-1990, and West Palm Beach-1994.

Susceptibility to Ciprofloxacin

Resistance to ciprofloxacin (a fluoroquinolone in the quinolone family of antimicrobials) was first identified in GISP sites in 1991. However since 1999, quinolone resistant Neisseria gonorrhoeae (QRNG) prevalence has steadily increased, first in Hawaii and the Pacific Islands, then in the Western states, and then among MSM.^6,8,9 In 2008, 775 (13.5%) of 5,723 GISP isolates collected were identified as QRNG, a decrease from 2007, when 891/6,009 (14.8%) isolates were identified as QRNG (Figure 27).

QRNG by Sexual Behavior

The prevalence of QRNG in isolates from MSM slightly decreased from 36.1% in 2007 to 33.6% in 2008. During the same time period, the prevalence of QRNG in isolates from heterosexuals also decreased from 8.7% in 2007 to 8.2% in 2008.

QRNG by Region

The number of isolates submitted from Honolulu demonstrating ciprofloxacin-resistance increased from 20 (28.6%) of 70 isolates in 2007 to 32 (40.5%) of 79 isolates in 2008. Other Western sites reporting increases in QRNG prevalence from 2007 to 2008 include: Phoenix (8.7% in 2007 to 16.5% in 2008); Portland (28.6% to 51.6%); and Seattle (29.3% to 31.3%). In contrast, a number of Western sites reported a decrease in QRNG prevalence from 2007 to 2008, including Albuquerque (16.7% in 2007 to 6.9% in 2008), Denver (17.0% to 10.7%), Las Vegas (18.7% to 17.7%), Los Angeles (22.4% to 16.8%), Orange County (41.0% to 33.3%), San Diego (36.3% to 29.1%) and San Francisco (31.3% to 26.1%).

In the South from 2007 to 2008, a few sites continued to observe increases in the prevalence of QRNG, including Atlanta (from 2.6% in 2007 to 10.3% in 2008), Baltimore (2.0% in 2007 to 5.4%) and Richmond (17.9% to 21.8%). Southern sites reporting a decrease in the prevalence of QRNG from 2007 to 2008 include Birmingham (from 9.4% in 2007 to 8.3% in 2008), Dallas (7.5% to 7.1%), Greensboro (5.3% to 3.6%), Miami (19.6% to 16.2%), New Orleans (18.1% to 14.9%), and Oklahoma City (6.0% to 4.4%).

A majority of the Midwestern sites reported decreases in QRNG prevalence including Chicago (from 8.6% in 2007 to 5.3% in 2008), Detroit (1.7% to 1.1%), Kansas City (16.4% to 7.5%), and Minneapolis (10.7% to 7.6%). The sites that showed an increase in QRNG prevalence were Cincinnati (from 1.2% in 2007 to 2.2% in 2008) and Cleveland (0.7% to 4.1%).

In the Northeast, New York City reported a slight increase in QRNG prevalence from 14.9% in 2007 to 15.5% in 2008. In Philadelphia, the prevalence of resistant isolates to ciprofloxacin decreased from 29.1% in 2007 to 20.6% in 2008.

Other Antimicrobial Susceptibility Testing

Overall in 2008, 24.4% of isolates collected from GISP sites were resistant to penicillin, tetracycline, ciprofloxacin, or some combination of those antibiotics (Figure 28). With the renewed availability of cefixime, susceptibility testing for this antibiotic was restarted in 2009. Additionally, susceptibility testing for cefpodoxime was started in 2009.

Antimicrobial Treatments Given for Gonorrhea

The antimicrobial agents given to GISP patients for gonorrhea therapy are shown in Figure 29. The proportion of GISP patients treated with cephalosporins has increased again from 81.0% in 2007 to 95.1% in 2008. Specifically, 75.1% were treated with ceftriaxone in 2008 compared with 61.5% in 2007. Conversely, the proportion of GISP patients being treated with fluoroquinolones (ciprofloxacin, ofloxacin or levofloxacin) has continued to decrease from 17.1% in 2007 to 2.2% in 2008. Treatment with azithromycin has slightly increased from 0.8% in 2007 to 1.2% in 2008.

Additional information on 2008 GISP data may be found on the GISP website: http://www.cdc.gov/std/GISP

Gonorrhea Among Special Populations

Additional information about gonorrhea in racial and ethnic minority populations, women of reproductive age, adolescents, MSM, and other at risk populations can be found in the Special Focus Profiles.

Gonorrhea Summary

In summary, the national gonorrhea rate has remained relatively unchanged for more than ten years. Of particular concern are the persistent high rates in some geographic areas, adolescents and young adults, and some racial/ethnic groups.

GISP continues to monitor for the emergence of decreased susceptibility and resistance to cephalosporins and for increases in decreased susceptibility to azithromycin.

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. Increases in gonorrhea–Eight western states, 2000–2005. MMWR 2007;56:222–225.

³ Centers for Disease Control and Prevention. Update to CDC’s Sexually Transmitted Diseases Treatment Guidelines, 2006: Fluoroquinolones No Longer Recommended for Treatment of Gonococcal Infections. MMWR, 2007;56: 332–336.

⁴ Centers for Disease Control and Prevention. Gonorrhea–United States, 1998. MMWR 2000;49:538–42.

⁵ 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.

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 2007 Supplement: Gonococcal Isolate Surveillance Project (GISP) Annual Report 2007. Atlanta, GA: U.S. Department of Health and Human Services.

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.

¹² Wang SA, Harvey AB, Conner SM, et al. Antimicrobial Resistance for Neisseria gonorrhoeae in the United States, 1988 to 2003: The Spread of Fluoroquinolone Resistance. Annals of Internal Medicine 2007;147:81–89.

¹³ Schwarcz S, Zenilman J, Schnell D, et al. National surveillance of antimicrobial resistance in Neisseria gonorrhoeae. JAMA 1990;264:1413–1417.