Gonorrhea is a significant public health problem in the United States. The number of reported gonorrhea cases probably underestimates the true incidence and has been influenced by changes in screening practices, use of diagnostic tests with different performance characteristics, and reporting practices. The rate of gonorrhea declined by 74% from 1975 to 1997 after implementation of a national gonorrhea control program in the mid-1970s. After 1997, gonorrhea rates declined further, reaching a historic low of 98.1 cases per 100,000 population in 2009. However, during 2009–2012, the gonorrhea rate increased each year, with 106.7 cases per 100,000 population reported in 2012. A slight decline occurred in 2013, but the rates then increased again during 2014 and 2015 (Figure 1). In 2015, a total of 395,216 gonorrhea cases were reported, for a rate of 123.9 cases per 100,000 population, an increase of 12.8% from 2014. Based on the estimated incident cases among all ages in 2008, the total lifetime direct medical cost of gonorrhea in the US was estimated at $162.1 million.
Epidemiology by Demographics
The incidence of gonorrhea remains high in some groups as defined by geography, age, race/ethnicity, or sexual risk behavior. During 2014–2015, rates of reported gonorrhea increased 18.3% among men and 6.8% among women. Gonorrhea rates among both men and women increased in every region of the United States, with the largest increases occurring in the West and the South.
Rates by Region and State
In the United States, the highest reported rates of gonorrhea are in the South, followed by the West, then Midwest, and Northeast (Figure 2) . During 2014 to 2015, gonorrhea rates increased 18.1% in the West, 12.6% in the South, 11.6 % in the Northeast , and 8.9% in the Midwest. The highest rates, by state, occurred in Louisiana, North Carolina, and Mississippi; rates in the District Columbia (416.2 per 100,000 population) was markedly higher than rates in any state (Figure 3).
Rates by Sex
During 2015, the rate of reported gonorrhea cases among men (140.9 cases per 100,000 males) was significantly higher than among women (107.2 cases per 100,000 females). During 2011 to 2015, the rate among men increased 44.2%, while the rate among women decreased 0.7% (Figure 4). Gonorrhea, rates by gender). The magnitude of increase among males likely reflected an increase among men who have sex with men, either due to increased transmission or increased case ascertainment.
Rates by Race/Ethnicity
The incidence of gonorrhea is by far highest among blacks, with the next highest rates in American Indian/Alaska Natives (Figure 5). The rate of gonorrhea in blacks is approximately 9.6 times greater than in whites. During 2011 to 2015, the gonorrhea rate increased among American Indians/Alaska Natives, whites, Hispanics, Asians, and Native Hawaiians/Other Pacific Islanders. Notably, during this same time period, the gonorrhea rate decreased by 4.0% among blacks.
Rates by Age Group
In 2015, the highest rates of gonorrhea among women were observed among those aged 20-24 years (5346.9 cases per 100,000 females) and 15-19 years (442.2 cases per 100,000 females). Among men, the rate was highest among those aged 20-24 years (539.1 cases per 100,000 males) and 25–29 years (448.8 cases per 100,000 males) (Figure 6).
Antimicrobial Susceptibility of N. gonorrhoeae
Antimicrobial resistance remains an important consideration in the treatment of gonorrhea.[2,3,4,5,6,7,8...] Much of the information regarding antimicrobial susceptibility of N. gonorrhoeae isolates in the United States comes from the CDC’s Gonococcal Isolate Surveillance Project (GISP). This microbiologic surveillance project has performed ongoing antibiotic susceptibility testing and tracks minimum inhibitory concentrations (MICs) in clinical isolates from men to determine the antimicrobial concentration needed to kill N. gonorrhoeae in the laboratory. Higher MICs indicate the need for higher antibiotic concentrations to effectively treat the bacteria. Increases above a defined cut-off indicate resistance to that antibiotic, and progressive increases in MICs below that cut-off suggest that resistance might eventually emerge. Laboratory-based data demonstrate that more widespread resistance has emerged with some antimicrobials and might develop in the near future with others, thus highlighting the need for ongoing surveillance. The GISP tracks primary antimicrobial drugs used to treat gonorrhea in the United States and N. gonorrhoeae susceptibility to 7 antimicrobials: ceftriaxone, cefixime, azithromycin, spectinomycin, ciprofloxacin, penicillin, and tetracycline (Figure 7).[1,2] These specific drugs are tested because they either are currently or were previously used for gonorrhea treatment.
- Ceftriaxone: During 2007–2014, the percentage of isolates with reduced ceftriaxone susceptibility (defined as MIC ≥0.125 μg/mL) fluctuated between 0.1% and 0.4%. Five isolates with ceftriaxone MIC equal or greater than 0.5 μg/mL have been reported.
- Cefixime: The proportion of N. gonorrhoeae isolates in the United States with elevated cefixime minimum inhibitory concentrations (MICs) increased significantly from 2009 to 2011, but has fallen since 2011. In 2015, the percentage of elevated cefixime MICs (≥0.25 μg/mL) was 0.5%.
- Azithromycin: Gonococcal azithromycin resistance has been tracked since 1992. From 2011–2015, the percentage of isolates with reduced azithromycin susceptibility (MICs ≥2 μg/mL) ranged from 0.3% to 0.6%; between 2013 and 2015, the percentage increased from 0.6% to 2.6%.
- Ciprofloxacin: Ciprofloxacin-resistant N. gonorrhoeae is widely disseminated throughout the U.S. and the world. In 2015, 22.3% of GISP isolates were resistant to ciprofloxacin. Because of this, fluoroquinolones, such as ciprofloxacin, are no longer recommended as therapy for gonorrhea.
- Other Antimicrobials: In 2015, 39.6 % of isolates were resistant to penicillin, tetracycline, ciprofloxacin, or some combination of those antimicrobials. Although these antimicrobials are no longer recommended for treatment of gonorrhea, these resistance phenotypes remain common.Check