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 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 evidence that gonococcal infections facilitate the transmission of HIV infection.¹ Although an individual’s sexual behavior can increase the risk of acquiring gonorrhea, social determinants of health, such as socioeconomic status, may contribute to the burden of gonorrhea in a community.²

In 2009, the national rate of reported gonorrhea cases reached an historic low of 98.1 cases per 100,000 population (Figure 11 and Table 1). However, during 2009–2012, the rate increased slightly each year, to 106.7 cases per 100,000 population in 2012. In 2013, a total of 333,004 gonorrhea cases were reported, and the national gonorrhea rate decreased slightly to 106.1 cases per 100,000 population.

The decrease in gonorrhea rate during 2012–2013 was observed primarily among women (Figure 12). Although trends by sex varied by region, nationwide, the gonorrhea rate decreased among women, but increased among men. Overall, the gonorrhea rate decreased in the Northeast, Midwest, and South, but increased in the West (Figure 13). The rate decreased among persons aged 15–19 years and 20–24 years, but increased among those aged 25 years or older (Table 21).

N. gonorrhoeae has progressively developed resistance to each of the antimicrobials used for treatment of gonorrhea. Most recently, declining susceptibility to cefixime resulted in a change to the CDC treatment guidelines, so that dual therapy with ceftriaxone and either azithromycin or doxycycline is now the only CDC-recommended treatment regimen for gonorrhea.³ The emerging threat of cephalosporin resistance highlights the need for continued surveillance of N. gonorrhoeae antimicrobial susceptibility.

The combination of persistently high gonorrhea morbidity in some populations and the threat of cephalosporin-resistant gonorrhea reinforces the need to better understand the epidemiology of gonorrhea.

Interpreting Rates of Reported Cases of Gonorrhea

Although gonorrhea case reporting is useful for monitoring disease trends, the number of gonorrhea cases reported to CDC is affected by many factors in addition to the actual occurrence of the infection within the population. Changes in the burden of gonorrhea may be masked by changes in screening practices (e.g., screening for chlamydia with tests that also detect N. gonorrhoeae infections or increased screening at extra-genital anatomic sites), the use of diagnostic tests with different test performance (e.g., the broader use of nucleic acid amplification tests [NAATs]), and changes in reporting practices. As with other STDs, the reporting of gonorrhea cases to CDC is incomplete.⁴ For these reasons, supplemental data on gonorrhea prevalence in persons screened in a variety of settings are useful in assessing the burden of disease in selected populations.

Gonorrhea—United States

In 2013, a total of 333,004 cases of gonorrhea were reported in the United States, yielding a rate of 106.1 cases per 100,000 population (Table 1). The rate decreased 0.6% since 2012; however, the rate increased 8.2% overall during 2009–2013.

Gonorrhea by Region

In 2013, as in previous years, the South had the highest rate of reported gonorrhea cases (128.6 cases per 100,000 population) among the four regions of the United States, followed by the Midwest (108.6 cases per 100,000 population), Northeast (85.5 cases per 100,000 population), and West (83.5 cases per 100,000 population) (Table 14). During 2012–2013, the gonorrhea rate decreased 7.3% in the Northeast, 5.0% in the Midwest, and 1.5% in the South, but increased 15.0% in the West (Figure 13, Table 14).

Gonorrhea by State

In 2013, rates of reported gonorrhea cases per 100,000 population ranged by state from 9.2 in New Hampshire to 188.4 in Louisiana; the gonorrhea rate in the District of Columbia was 391.9 per 100,000 population (Figure 14, Table 13). During 2012–2013, gonorrhea rates increased in 50% (25/50) of states and in the District of Columbia, decreased in 48% (24/50) of states, and did not change in one state (Table 14).

Gonorrhea by Metropolitan Statistical Area (MSA)

The overall rate of reported gonorrhea cases in the 50 most populous MSAs was 118.1 cases per 100,000 population in 2013 (Table 17), representing a 1.6% decrease compared with 2012 (120.0 cases per 100,000 population). In 2013, 60.7% of reported gonorrhea cases were reported by these MSAs. Since 2010, the gonorrhea rate among women in the 50 most populous MSAs has been lower than the rate among men (Tables 18 and 19). In 2013, the rate among women was 105.4 cases per 100,000 population, while the rate among men was 130.8 cases per 100,000 population.

Gonorrhea by County

In 2013, 51% of reported gonorrhea cases occurred in just 70 counties or independent cities (Table 20). In 2013, 1,108 counties (35.3%) in the United States had a rate less than or equal to 19 cases per 100,000 population (Figure 15). The rate ranged from 19.1 to 100 per 100,000 population in 1,424 counties (45.3%), and was more than 100 cases per 100,000 population in 610 counties (19.4%). As in previous years, most counties with more than 100 cases per 100,000 population were located in the South.

Gonorrhea by Sex

In 2013, for the first time since 2000, the rate of reported gonorrhea cases among men (109.5 cases per 100,000 population) was higher than the rate among women (102.4 cases per 100,000 population) (Figure 12, Tables 15 and 16). During 2012–2013, the gonorrhea rate among men increased 4.3%, and the rate among women decreased 5.1% During 2009–2013, the rate among men increased 20.3%, while the rate among women decreased 2.0%. The magnitude of the increase among men compared with a decrease among women suggests either increased transmission or increased case ascertainment (e.g., through increased extra-genital screening) among gay, bisexual, and other men who have sex with men (collectively referred to as MSM). However, most jurisdictions do not routinely report sex of sex partner or site of infection for gonorrhea cases, so trends in gonorrhea rates among MSM over time cannot be assessed.

Gonorrhea by Region and Sex

During 2012–2013 in the West, the rate of reported gonorrhea cases increased among men (17.3%) and among women (11.8%) (Tables 15 and 16). In contrast, in the Midwest and the South, the gonorrhea rate increased among men (increased 0.6% in the Midwest, 2.4% in the South), but decreased among women (decreased 9.2% in the Midwest, 5.0% in the South). In the Northeast, the gonorrhea rate decreased among men (1.9%) and among women (13.2%).

Gonorrhea by Age

In 2013, rates of reported gonorrhea cases were highest among adolescents and young adults. In 2013, the highest rates among women were observed among those aged 20–24 years (541.6 cases per 100,000 population) and 15–19 years (459.2 cases per 100,000 population). Among men, the rate was highest among those aged 20–24 years (459.4 cases per 100,000 population) (Figure 16, Table 21).

In 2013, persons aged 15–44 years accounted for 93.6% of reported gonorrhea cases with known age. During 2012–2013, the gonorrhea rate decreased 11.6% among those aged 15–19 years, and decreased 1.9% among those aged 20–24 years (Table 21). However, the gonorrhea rate increased 6.3% among those aged 25–29 years, 8.4% among those aged 30–34 years, 11.3% among those aged 35–39 years, and 7.9% among those aged 40–44 years.

Among women aged 15–44, the rate decreased among those aged 15–19 years and 20–24 years, but increased in older age groups (Figure 17). Among men aged 15–44, the rate decreased among those aged 15–19 years, but increased in those aged 20–24 years and in older age groups (Figure 18).

Gonorrhea by Race/Ethnicity

In 2013, among the 47 jurisdictions (46 states and the District of Columbia) that submitted data in the race and ethnicity categories according to Office of Management and Budget (OMB) standards, the rate of reported gonorrhea cases remained highest among blacks (426.6 cases per 100,000 population) (Table 22B). The rate among blacks was 12.4 times the rate among whites (34.5 cases per 100,000 population). The gonorrhea rate among American Indians/Alaska Natives (137.4 cases per 100,000 population) was 4.0 times that of whites, the rate among Native Hawaiians/Other Pacific Islanders (94.0 cases per 100,000 population) was 2.7 times that of whites, the rate among Hispanics (65.8 cases per 100,000 population) was 1.9 times that of whites, and the rate among Asians (17.1 cases per 100,000 population) was 0.5 times that of whites (Table 22B).

During 2009–2013, among the 40 jurisdictions (39 states and the District of Columbia) that submitted data in the OMB-compliant race and ethnicity categories for all five years during that period, the gonorrhea rate increased among American Indians/Alaska Natives (87.4%), Native Hawaiians/Other Pacific Islanders (79.1%), whites (54.4%), Hispanics (50.2%), and Asians (29.4%) (Figure 19). During this same time period, the gonorrhea rate decreased 9.1% among blacks.

More information on gonorrhea rates among racial/ethnicity groups can be found in the Special Focus Profiles.

Gonorrhea by Reporting Source

The number of gonorrhea cases reported by STD clinics declined during 2004–2013 (Figure 20). In 2013, 16.3% of gonorrhea cases with known reporting source were reported by STD clinics (Table A2). This is a decrease from 2012, when 17.3% of gonorrhea cases were reported by STD clinics. In 2013, among women, private physicians or health maintenance organizations (HMOs) (25.5%) were the most common reporting source, followed by family planning clinics (9.4%), STD clinics (8.6%), other health department clinics (6.6%), and emergency rooms (5.2%) (Figure 21). Among men, private physicians/HMOs (20.1%) and STD clinics (19.8%) were the most common reporting sources. Other reporting sources for men included other health department clinics (8.5%), emergency rooms (5.5%), and family planning clinics (5.2%).

STD Surveillance Network

The STD Surveillance Network (SSuN) is a network of 12 states and independently funded cities that collect enhanced information on a representative sample of gonorrhea cases reported to the state or city health department from all reporting sources. This project provides more complete estimates of case characteristics often missing on routine case reports—such as gender of sex partners—which is essential for better targeting of gonorrhea control efforts. Between January 1st and June 30th, 2013, SSuN collaborators interviewed 3,121 gonorrhea cases representing 8.1% of total morbidity reported from participating jurisdictions during that time period. Based on these enhanced interviews, the burden of disease represented by MSM, men who have sex with women only (MSW), and women varied substantially across collaborating sites (Figure 22). San Francisco County had the highest proportion of estimated MSM cases (82.6%), while the lowest proportion of morbidity estimated to be attributed to MSM was found in Virginia at 13.0%. Across all SSuN jurisdictions in 2013, 27.4% of gonorrhea cases were estimated to be among MSM, 30.5% among MSW, and 42.1% among women.

In addition, a total of 42 STD clinics in the 12 SSuN jurisdictions collected enhanced behavioral information from patients who presented for care at these clinics during 2013. In 2013, the proportion of STD clinic patients who tested positive for gonorrhea varied by age, sex, and sex of sex partner (Figure 23). Among those attending these clinics, adolescent MSW ≤19 years of age had the highest gonorrhea positivity (32.4%). Within older age groups, MSM had a higher gonorrhea positivity than MSW or women.

Additional information about SSuN methodology can be found in the STD Surveillance Network section of the Appendix, Interpreting STD Surveillance Data.

Gonococcal Isolate Surveillance Project

Antimicrobial resistance remains an important consideration in the treatment of gonorrhea.^{3, 5–9} In 1986, the Gonococcal Isolate Surveillance Project (GISP), a national sentinel surveillance system, was established to monitor trends in antimicrobial susceptibilities of urethral N. gonorrhoeae strains in the United States.¹⁰ Data are collected from selected STD clinic sentinel sites and from regional laboratories (Figure 24).

Information on the antimicrobial susceptibility criteria used in GISP can be found in the Gonococcal Isolate Surveillance Project section of the Appendix, Interpreting STD Surveillance Data. More information about GISP and additional data can be found at http://www.cdc.gov/std/GISP.

Susceptibility to Ceftriaxone

Susceptibility testing for ceftriaxone began in 1987. The percentage of GISP isolates that exhibited elevated ceftriaxone minimum inhibitory concentrations (MICs), defined as ≥0.125 µg/ml, increased from 0.1% in 2008 to 0.4% in 2011, and decreased to 0.05% in 2013 (Figure 25).

Five isolates with decreased susceptibility to ceftriaxone (MIC = 0.5 µg/ml) have been previously identified in GISP: one from San Diego, California (1987), two from Cincinnati, Ohio (1992 and 1993), one from Philadelphia, Pennsylvania (1997), and one from Oklahoma City, Oklahoma (2012).

Susceptibility to Cefixime

Susceptibility testing for cefixime began in 1992, was discontinued in 2007, and was restarted in 2009. The percentage of isolates with elevated cefixime MICs (≥0.25 µg/ml) increased from 0.1% in 2006 to 1.4% in 2010 and 2011, and declined to 0.4% in 2013 (Figure 26). In 2013, no isolates had cefixime MICs of ≥0.5 µg/ml.

Susceptibility to Azithromycin

Susceptibility testing for azithromycin began in 1992. Figure 27 displays the distribution of azithromycin MICs among GISP isolates collected during 2009–2013. Most isolates had MICs of 0.125–0.25 µg/ml. The proportion of GISP isolates with azithromycin MICs of ≥2.0 µg/ml varied by year between 0.2% and 0.6%.

Susceptibility to Spectinomycin

All isolates were susceptible to spectinomycin in 2013. A spectinomycin-resistant isolate was last identified in GISP in 1994 (West Palm Beach, Florida).

Susceptibility to Ciprofloxacin

The proportion of GISP isolates with ciprofloxacin resistance (MIC ≥1 µg/ml) peaked in 2007 at 14.8%. Following a decline in 2008 and 2009, the proportion increased from 9.6% in 2009 to 16.1% in 2013. In 2013, 27.7% of isolates from MSM and 9.8% of isolates from MSW exhibited ciprofloxacin resistance.

Other Antimicrobial Susceptibility Testing

In 2013, 33.9% of isolates collected from GISP sites were resistant to penicillin, tetracycline, ciprofloxacin, or some combination of those antimicrobials (Figure 28). Although these antimicrobials are no longer recommended for treatment of gonorrhea, the resistance phenotypes remain common. Conversely, 66.1% of isolates were susceptible to all three of these antimicrobials.

Antimicrobial Treatments Given for Gonorrhea

The antimicrobial agents given to GISP patients for gonorrhea therapy are shown in Figure 29. The proportion of patients treated with ceftriaxone 250 mg increased from 84.0% in 2011 to 96.9% in 2013. The proportion treated with cefixime decreased from 5.3% in 2011 to 0.02% in 2013. In 2013, 1.7% of patients were treated with azithromycin 2 grams as monotherapy.

Among patients treated with ceftriaxone 250 mg in 2013, 95.4% were also treated with azithromycin one gram, 4.0% were also treated with doxycycline, and 0.5% did not receive a second antimicrobial.

Gonorrhea Among Special Populations

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

Gonorrhea Summary

The national rate of reported gonorrhea cases reached an historic low in 2009, but increased each year during 2009–2012. In 2013, the gonorrhea rate decreased slightly. This decrease was largely attributable to a decrease among women. The gonorrhea rate among men increased in every region except the Northeast, while the gonorrhea rate among women decreased in every region except the West. High gonorrhea rates persist in some geographic areas, among adolescents and young adults, and in some racial/ethnic groups.

GISP continues to monitor for the emergence of decreased susceptibility and resistance to cephalosporins and 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;75(1):3–17.

2    Sullivan AB, Gesink DC, Brown P, Zhou L, Kaufman JS, Fitch M, et al. Are neighborhood sociocultural factors influencing the spatial pattern of gonorrhea in North Carolina? Ann Epidemiol. 2011; 21:245–252.

3    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 infections. MMWR Morb Mortal Wkly Rep. 2012;61(31):590–594.

4    Satterwhite CL, Torrone E, Meites E, Dunne EF, Mahajan R, Ocfemia MC et al. Sexually transmitted infections among US women and men: prevalence and incidence estimates, 2008. Sex Transm Dis. 2013; 40(3):187–193.

5    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 Morb Mortal Wkly Rep. 2007;56:332–6.

6    Centers for Disease Control and Prevention. Sexually transmitted diseases treatment guidelines, 2010. MMWR Recomm Rep. 2010;59(No.RR-12).

7   Centers for Disease Control and Prevention. Neisseria gonorrhoeae with reduced susceptibility to azithromycin — San Diego County, California, 2009. MMWR Morb Mortal Wkly Rep. 2011;60:579–81.

8    Centers for Disease Control and Prevention. Cephalosporin susceptibility among Neisseria gonorrhoeae isolates—United States, 2000–2010. MMWR Morb Mortal Wkly Rep. 2011;60:873–7.

9    Kirkcaldy RD, Ballard RC, Dowell D. Gonococcal resistance: Are cephalosporins next? Curr Infect Dis Rep. 2011;13: 196–204.

10  Schwarcz S, Zenilman J, Schnell D, Knapp JS, Hook EW 3rd, Thompson S, et al. National surveillance of antimicrobial resistance in Neisseria gonorrhoeae. JAMA. 1990;264:1413–7.

Next