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 Together sexual behavior and community prevalence can increase the risk of acquiring gonorrhea. Social determinants of health, such as socioeconomic status, discrimination, and access to quality health care, 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 12 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, the rate decreased slightly to 105.3 cases per 100,000 population. In 2014, a total of 350,062 gonorrhea cases were reported, and the national gonorrhea rate increased to 110.7 cases per 100,000 population.

The increase in gonorrhea rate during 2013–2014 was observed primarily among men (Figure 13). Overall, the gonorrhea rate increased in the South and the West, but decreased in the Northeast and Midwest (Figure 14). The rate increased among persons aged 20–24 years and in older age groups, but decreased among younger age groups (Table 21).

N. gonorrhoeae has progressively developed resistance to each of the antimicrobials used for treatment of gonorrhea. Most recently, declining susceptibility to cefixime (an oral cephalosporin antibiotic) resulted in a change to the CDC treatment guidelines, so that dual therapy with ceftriaxone (an injectable cephalosporin) and azithromycin 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 2014, a total of 350,062 cases of gonorrhea were reported in the United States, yielding a rate of 110.7 cases per 100,000 population (Table 1). The rate increased 5.1% since 2013, and increased 10.5% since 2010.

Gonorrhea by Region

In 2014, as in previous years, the South had the highest rate of reported gonorrhea cases (131.4 cases per 100,000 population) among the four regions of the United States, followed by the Midwest (106.6 cases per 100,000 population), West (101.1 cases per 100,000 population), and Northeast (84.7 cases per 100,000 population) (Table 14). During 2013–2014, the gonorrhea rate increased 22.2% in the West and 3.1% in the South, but decreased 1.5% in the Midwest and 0.6% in the Northeast (Figure 14, Table 14).

Gonorrhea by State

In 2014, rates of reported gonorrhea cases per 100,000 population ranged by state from 13.4 in Vermont to 194.6 in Louisiana; the gonorrhea rate in the District of Columbia was 291.3 per 100,000 population (Figure 15, Table 13). During 2013–2014, gonorrhea rates increased in 70% (35/50) of states, and decreased in 30% (15/50) of states and the District of Columbia (Table 14).

Gonorrhea by Metropolitan Statistical Area

The overall rate of reported gonorrhea cases in the 50 most populous metropolitan statistical areas (MSAs) was 122.8 cases per 100,000 population in 2014 (Table 17), representing a 5.0% increase compared with 2013 (117.0 cases per 100,000 population). In 2014, 60.6% 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 2014, the rate among women in these MSAs was 102.0 cases per 100,000 females, while the rate among men was 144.1 cases per 100,000 males.

Gonorrhea by County

In 2014, 50% of reported gonorrhea cases occurred in just 70 counties or independent cities (Table 20). In 2014, 792 counties (25.2%) in the United States had a rate less than or equal to 13 cases per 100,000 population (Figure 16). The rate ranged from 14 to 36 per 100,000 population in 791 counties (25.2%), ranged from 37 to 91 per 100,000 population in 777 counties (24.7%), and was more than 91 cases per 100,000 population in 782 counties (24.9%). As in previous years, counties with the highest gonorrhea rates were concentrated in the South.

Gonorrhea by Sex

As was observed in 2013, in 2014 the rate of reported gonorrhea cases among men (120.1 cases per 100,000 males) was higher than the rate among women (101.3 cases per 100,000 females) (Figure 13, Tables 15 and 16). During 2013–2014, the gonorrhea rate among men increased 10.5%, and the rate among women decreased 0.4%. During 2010–2014, the rate among men increased 27.9%, while the rate among women decreased 4.1%. 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 2013–2014 in the West, the rate of reported gonorrhea cases increased among men (25.7%) and among women (16.9%) (Tables 15 and 16). Similarly, in the South, the rate of reported gonorrhea cases increased both among men (6.2%) and among women (0.6%). In contrast, in the Northeast and Midwest, the gonorrhea rate increased among men (increased 8.9% in the Northeast, 4.2% in the Midwest), but decreased among women (decreased 12.0% in the Northeast, 6.5% in the Midwest).

Gonorrhea by Age

In 2014, rates of reported gonorrhea cases continued to be highest among adolescents and young adults (Figure 17, Table 21). In 2014, the highest rates among women were observed among those aged 20–24 years (533.7 cases per 100,000 females) and 15–19 years (430.5 cases per 100,000 females). Among men, the rate was highest among those aged 20–24 years (485.6 cases per 100,000 males) and 25–29 years (370.5 cases per 100,000 males).

In 2014, persons aged 15–44 years accounted for 93.2% of reported gonorrhea cases with known age. During 2013–2014, the gonorrhea rate decreased 5.0% among those aged 15–19 years (Table 21). However, the gonorrhea rate increased 2.8% among those aged 20–24 years, 12.1% among those aged 25–29 years, 12.7% among those aged 30–34 years, 15.3% among those aged 35–39 years, and 7.4% among those aged 40–44 years.

Among women aged 15–44 years, the rate decreased among those aged 15–19 years and 20–24 years, but increased in older age groups during 2013–2014 (Figure 18). Among men aged 15–44 years, the rate decreased among those aged 15–19 years, but increased in those aged 20–24 years and in older age groups during 2013–2014 (Figure 19).

Gonorrhea by Race/Ethnicity

In 2014, among the 48 states that submitted data in the race and ethnicity categories according to Office of Management and Budget (OMB) standards (see Section A1.5 in the Appendix), the rate of reported gonorrhea cases remained highest among blacks (405.4 cases per 100,000 population) (Table 22B). The rate among blacks was 10.6 times the rate among whites (38.3 cases per 100,000 population). The gonorrhea rate among American Indians/Alaska Natives (159.4 cases per 100,000 population) was 4.2 times that of whites, the rate among Native Hawaiians/Other Pacific Islanders (102.1 cases per 100,000 population) was 2.7 times that of whites, the rate among Hispanics (73.3 cases per 100,000 population) was 1.9 times that of whites, and the rate among Asians (19.3 cases per 100,000 population) was 0.5 times that of whites.

During 2010–2014, among the 43 states that submitted race and ethnicity data according to OMB standards (see Section A1.5 in the Appendix) for all five years during that period, the gonorrhea rate increased among American Indians/Alaska Natives (100.3%), whites (59.3%), Hispanics (51.2%), Asians (45.3%), and Native Hawaiians/Other Pacific Islanders (44.2%) (Figure 20). During this same time period, the gonorrhea rate decreased 8.2% among blacks.

More information on gonorrhea rates among race/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 2005–2014 (Figure 21). In 2014, 15.1% of gonorrhea cases with known reporting source were reported by STD clinics (Table A2). This is a decrease from 2013, when 16.3% of gonorrhea cases were reported by STD clinics. In 2014, among women, private physicians or health maintenance organizations (HMOs) (25.1%) were the most common reporting source, followed by family planning clinics (8.5%), STD clinics (8.2%), other health department clinics (6.6%), and emergency rooms (5.5%) (Figure 22). Among men, private physicians/HMOs (20.5%) and STD clinics (17.2%) were the most common reporting sources. Other reporting sources for men included other health department clinics (8.7%), emergency rooms (5.9%), and family planning clinics (4.7%).

STD Surveillance Network

The STD Surveillance Network (SSuN) is an ongoing collaboration of states and independently funded cities collecting enhanced information on a representative sample of gonorrhea case reports received from all reporting sources in their jurisdiction. Enhanced gonorrhea case report data for this report were obtained from Cycle 2 of SSuN, which included 12 sites collecting data through June 2013. These data for 2014 are not yet available due to transition to SSuN Cycle 3, which includes different sites and new data collection protocols. Subsequent cycles of SSuN will continue to provide 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 1 and June 30, 2013, SSuN cycle 2 collaborators interviewed 3,121 gonorrhea cases representing 8.1% of total morbidity reported from participating jurisdictions during that time period. The estimated burden of disease represented by MSM, men who have sex with women only (MSW), and women varied substantially across collaborating sites (Figure 23). 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 collaborating jurisdictions in 2013, 27.4% of gonorrhea cases were estimated to be among MSM, 30.5% among MSW, and 42.1% among women.

Enhanced clinical and behavioral information is also collected among patients attending STD clinics in SSuN jurisdictions. Clinic data for this report include information from patients attending STD clinics during 2014 in the 6 SSuN jurisdictions that were in both Cycle 2 and Cycle 3. In 2014, the proportion of STD clinic patients who tested positive for gonorrhea varied by age, sex, and sex of sex partner (Figure 24). Among those attending these clinics, MSM disproportionately have higher positivity rates when compared to MSW and women, especially among adolescent MSM ≤19 years of age (29.0%). Positivity rates decline with increasing age for MSM, MSW, and women.

Additional information about SSuN methodology can be found in Section A2.2 of the Appendix.

Gonococcal Isolate Surveillance Project

Antimicrobial resistance remains an important consideration in the treatment of gonorrhea.^3,5–7 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.⁷ Data are collected from selected STD clinic sentinel sites and from regional laboratories (Figure 25).

Antimicrobial susceptibility is measured by the minimum inhibitory concentration (MIC), the lowest antimicrobial concentration that inhibits bacterial growth in the laboratory. Increases in MICs demonstrate that the bacteria can survive at higher antimicrobial concentrations in the laboratory. Monitoring of MIC trends is useful because increasing MICs can oftentimes be an early indicator of the emergence of antimicrobial resistance.

Information on the antimicrobial susceptibility criteria used in GISP can be found in the Section A2.3 in the Appendix. More information about GISP and additional data can be found at https://www.cdc.gov/std/GISP.

Ceftriaxone Susceptibility

Susceptibility testing for ceftriaxone began in 1987. During 2006–2014, the percentage of GISP isolates that exhibited elevated ceftriaxone MICs, defined as ≥0.125 μg/ml, fluctuated between 0.1% and 0.4% (Figure 26).

Five isolates with decreased ceftriaxone susceptibility (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).

Cefixime Susceptibility

Susceptibility testing for cefixime began in 1992, was discontinued in 2007, and was restarted in 2009. The percentage of isolates with elevated cefixime MICs (≥0.25μg/ml) declined from 1.4% in 2010 and 2011 to 0.4% in 2013 (Figure 27); in 2014, the percentage was 0.8%.

Azithromycin Susceptibility

Susceptibility testing for azithromycin began in 1992. Figure 28 displays the distribution of azithromycin MICs among GISP isolates collected during 2010–2014. Most isolates had MICs of 0.125–0.5 μg/ml. From 2010–2013, the percentage of isolates with reduced azithromycin susceptibility (MICs ≥ 2 μg/ml) ranged from 0.3% to 0.6%; between 2013 and 2014, the percentage increased from 0.6% to 2.5%.

Spectinomycin Susceptibility

All isolates were susceptible to spectinomycin in 2014. A spectinomycin-resistant isolate was last identified in GISP in 1994 (West Palm Beach, Florida).

Ciprofloxacin Susceptibility

During 1999–2007, the prevalence of ciprofloxacin increased from 0.4% to 14.8%. The prevalence declined in 2008 and 2009 and then increased. In 2014, 19.2% of GISP isolates were resistant to ciprofloxacin. Among isolates from MSM, 29.7% were resistant; 12.7% of isolates from MSW exhibited ciprofloxacin resistance.

Susceptibility to Other Antimicrobials

In 2014, 37.0% of isolates collected from GISP sites were resistant to penicillin, tetracycline, ciprofloxacin, or some combination of those antimicrobials (Figure 29). Although these antimicrobials are no longer recommended for treatment of gonorrhea, the resistance phenotypes remain common. Conversely, 63.0% 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 30. The proportion of patients treated with ceftriaxone 250 mg increased from 84.0% in 2011 to 96.9% in 2013. In 2014, 93.7% of patients were treated with ceftriaxone 250 mg, 1.9% of patients were treated with azithromycin 2 grams as monotherapy, and 1 patient (<0.1%) was treated with cefixime.

Gonorrhea Among Special Populations

More information about gonorrhea in race/ethnicity groups, women of reproductive age, adolescents, and MSM 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. After a temporary decrease in 2013, the gonorrhea rate increased again in 2014. This increase was largely attributable to an increase among men. High gonorrhea rates persist in certain 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.

     

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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. Hogben M, Leichliter JS. Social determinants and sexually transmitted disease disparities. Sex Transm Dis. 2008 Dec; 35 (12 Suppl):S13-18.

3 Centers for Disease Control and Prevention. Sexually transmitted diseases treatment guidelines, 2015. MMWR Morb Mortal Wkly Rep 2015; 64(No. RR-3): 1–137.

4 Satterwhite CL, Torrone E, Meites E, 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: 332–336.

6 Centers for Disease Control and Prevention. Sexually transmitted diseases treatment guidelines, 2010. MMWR Recomm Rep 2010; 59(No.RR-12): 1–110.

7 Schwarcz S, Zenilman J, Schnell D, et al. National surveillance of antimicrobial resistance in Neisseria gonorrhoeae. JAMA 1990; 264: 1413–141

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