Abstract
Common sexually transmitted infections (STIs) in the United States include genital herpes, HIV, and human papilloma virus. In 2017, the Centers for Disease Control and Prevention released a report detailing a surge in chlamydia, gonorrhea, and syphilis infections in the United States. The authors summarize current trends and discuss epidemiologic factors, disease burden, and patient care. It is important to be aware of the recent increases in these 3 STIs and to be prepared to screen for, diagnose, and manage these infections and their complications.
At least 16 sexually transmitted infections (STIs) are commonly found in the United States: anogenital warts, bacterial vaginosis, chlamydia, gonorrhea, genital herpes (herpes simplex virus [HSV]), HIV, human papillomavirus (HPV), granuloma inguinale, lymphogranuloma venereum,
Mycoplasma genitalium, pubic lice, scabies, syphilis, trichomonas vaginalis, viral hepatitis, and vulvovaginal candidiasis.
1 In September 2017, the Centers for Disease Control and Prevention (CDC) released a report that identified a surge in STIs, specifically, chlamydia, gonorrhea, and syphilis (
Chlamydia trachomatis,
Neisseria gonorrhoeae, and
Treponema pallidum, respectively).
2 The surge in the incidence of chlamydia, gonorrhea, and syphilis in the United States has reached a cumulative all-time high.
2 In 2016, more than 2 million new cases of these 3 STIs were reported in the United States, setting a record for the second year in a row.
2 Of note, these 3 infections, along with HIV, are the only STIs with federally funded control programs and are therefore reportable conditions.
2
The majority of new STIs diagnosed in 2016 were chlamydial, with 1.6 million newly diagnosed chlamydia infections—a 4.7% increase in incidence from 2015.
2 Chlamydia infection rates are highest among young females aged 15 to 24 years but are also increasing among men. Also, 470,000 new cases of gonorrhea were diagnosed in 2016. Compared with 2015, gonorrhea cases rose 22.2% among men and 13.8% among women in 2016.
2
The CDC reported 28,000 cases of primary and secondary syphilis in 2016, an increase of 18% from 2015. Most cases (88.9%) were seen in men, with a 14.7% increase from 2015. Men who have sex with men (MSM) accounted for 80.6% of male cases, and 47.0% of MSM cases were also HIV positive. Although men make up the majority of syphilis cases, rates in women have more than doubled since 2012. In that time, cases of congenital syphilis rose 86.9% (8.4 cases per 100,000 live births in 2012 compared with 15.7 cases per 100,000 live births in 2016). There were 628 cases of congenital syphilis reported in 2016, including 41 deaths among newborns.
2
The increase in gonorrhea and syphilis infections represents a sharp shift from previous trends. In 2009, the rate of gonorrhea cases reached a historic low of 98.1 cases per 100,000 population. Seven years later, the rate increased by almost 150%.
2 In 2000 and 2001, syphilis was reportedly close to elimination in the United States, with rates at their lowest since reporting began in 1941.
2
The rates of other common STIs in the United States have either declined or remained stable, including chancroid, HPV, HSV, and trichomonas.
2 However, their rates are often difficult to track, as most are not reportable conditions.
2 Human papilloma virus is the most common STI in the United States; however, the introduction of HPV vaccines has resulted in a significantly decreased prevalence in the postvaccine era (2009-2012) compared with the prevaccine era (2003-2006), particularly in females aged 14 to 24 years.
2 Rates of HSV are difficult to measure, as HSV is often subclinical and may never be formally diagnosed.
2 The prevalence of HSV-2 has decreased when comparing 1988-1994 and 2007-2010 rates.
2 Orolabial HSV-1 cases are declining in adolescents aged 14 to 19; however, genital HSV-1 cases may be increasing, owing to a variety of factors.
2 Trichomonas vaginalis rates also seem to have remained stable since the 1990s.
2 New diagnoses of HIV have been steadily declining, with a rate of 12.3 individuals per 100,000 population in 2016 compared with 13.5 in 2011.
3
Possible explanations for the increased incidence in chlamydia, gonorrhea, and syphilis include improved technology, which may contribute to the number of cases reported. Before 2002, diagnostic testing for chlamydia and gonorrhea was performed via culture. Bacterial culture presented significant difficulty with maintaining viability of organisms during transport, as well as difficulty with test standardization, high costs, and relative insensitivity of the test. This lack of efficacy prompted the development of nonculture tests, including enzyme immunoassays, direct fluorescent antibody tests, and nucleic acid hybridization tests. However, each of these tests failed to detect a significant number of infections. The development of nucleic acid amplification tests resulted in a new criterion standard for chlamydia and gonorrhea testing, as it is 20% to 35% more sensitive than the preceding nonculture tests.
4
Another contributing factor may be the low prevalence of condom use.
5 Every 5 years, the CDC performs a national survey asking men and women aged 15 to 44 years whether they used a condom during their most recent sexual intercourse in the past 12 months. A 2017 report comparing data from the 2006-2010 survey with data from the 2011-2015 survey found that the percentage of women who used a condom decreased from 25.3% to 23.8% over time, and the percentage of men remained stable (33.1% vs 33.7%).
5 Condom use rates of 23.8% and 33.7% are alarmingly low given their established role in preventing the spread of STIs.
With the increase in the 3 aforementioned STIs, there is a paradoxical decrease in funds available for STI screening. State and local STI programs continue to have budget cuts, with 52% of programs being cut and 21 clinics closing in 2012.
2 Fortunately, funding for STI prevention has increased. The fiscal year 2019 budget acknowledges the recent increase in chlamydia, gonorrhea, and syphilis and includes $152 million to fund the surveillance, prevention, and control of STIs. This is a $1 million increase from the amount allocated in the fiscal year 2018 budget.
6
Another potential explanation for the increased rates is poor sexual history taking and STI screening by health care professionals. The failure to detect STIs early could result in further propagation and spread of infections, as well as more long-term complications of these infections. A 2005 survey
7 of US medical schools and fourth-year medical students revealed that only 55.4% of schools surveyed had a sexual health curriculum. When asked about their comfort level in taking a sexual history, the students were most likely to be comfortable with patients aged 15 to 24 years (91%) and 25 to 50 years (93%) than with patients aged 10 to 14 years (57%), 51 to 75 years (67%) or older than 75 years (50%).
7 The students were also given case scenarios and asked whether they would screen each patient for chlamydia. Most students correctly chose to screen a 31-year-old pregnant woman (94%) and a sexually active 20-year-old woman (74%).
7 Forty-seven percent said that they would screen a 20-year-old man who had oral sex with another man.
7 This information indicates room for growth in sexual health education in medical school, including sexual history taking and STI screening.
Although chlamydia, gonorrhea, and syphilis can all be managed with antibiotics, dire consequences can result when these STIs are left undiagnosed and untreated. Infertility, ectopic pregnancy, stillbirth in infants, potentially fatal neurologic and cardiovascular complications, and increased risk for HIV transmission are potential medical complications that can result from untreated infections. Additionally, the stigmatization of subgroups of people in the United States who are disproportionately infected is of concern, including the MSM population, African Americans, and American Indians/Alaska Natives.
2
Antimicrobial resistance of
N gonorrhoeae is a growing concern in the medical community. Between 2013 and 2016, the rate of azithromycin resistance increased from 0.6% to 3.6%.
2 Within 10 years, cephalosporin-resistant
N gonorrhoeae could cause an estimated 75,000 additional cases of pelvic inflammatory disease, 15,000 cases of epididymitis, and 222 cases of HIV, which would cost $235 million in direct medical costs.
8
Financially, the rise in STIs is of great concern. In 2016, the total lifetime direct medical cost of treating 8 of the most common STIs contracted in a single year was $15.6 billion. This figure included $516.7 million for chlamydia, $162.1 million for gonorrhea, and $39.3 million for syphilis.
9 Due to inflation and the increase in cases in the past 10 years, these numbers will likely continue to rise.
In 2015, the CDC published their STD screening and treatment guidelines.
1 In general, these guidelines have the following screening recommendations.
All nonpregnant sexually active female patients younger than 25 years should be screened for chlamydia and gonorrhea. Women older than 25 years and at increased risk for infection may also be screened. Patients with a diagnosis of chlamydia or gonorrhea should be rescreened 3 months after treatment is completed. There are currently no guidelines for screening nonpregnant females for syphilis.
All pregnant patients younger than 25 years (or >25 years and at increased risk) should be screened for chlamydia and gonorrhea at the first prenatal visit, with repeated chlamydia screening in the third trimester. Pregnant patients with a chlamydia diagnosis should be rescreened 3 to 4 weeks after treatment and again 3 months later. Pregnant patients with a gonorrhea diagnosis should be rescreened 3 months after treatment. All pregnant patients should be screened for syphilis at the first prenatal visit, with repeated screening early in the third trimester and at delivery if at high risk.
Male patients should be screened for chlamydia if they are located in high prevalence clinical settings or are part of a population with a high burden of infection, regardless of age. Men who have sex with men should be screened for chlamydia, gonorrhea, and syphilis at least annually (every 3 to 6 months if at increased risk), regardless of condom use.
Sexually active males and females who are HIV positive should be screened for chlamydia, gonorrhea, and syphilis at their first HIV evaluation and at least annually thereafter.
The
Table outlines the CDC's diagnosis and treatment guidelines.
1 Partners should be encouraged to seek evaluation and to discuss screening for other STIs with a health care professional. The American College of Obstetricians and Gynecologists advocates for expedited partner therapy as a method of preventing gonorrhea and chlamydia reinfection when a patient's partners are unable or unwilling to seek medical care. Expedited partner therapy should only occur after a health care professional has assessed the risk of intimate partner violence associated with partner notification.
10 Expedited partner therapy is currently prohibited in 2 states (Kentucky and South Carolina) and limited in 7 states (Alabama, Delaware, Kansas, Oklahoma, New Jersey, South Dakota, and Virginia) and Puerto Rico.
11
Physicians and medical students have a duty to educate themselves and their patients about STIs. Familiarization with the prevention, screening, diagnosis, and treatment guidelines for STIs is essential. But it is also important to recognize the variety of STI presentations and the multitude of both acute and chronic complications that occur with unrecognized or untreated cases.
The National Coalition for Sexual Health recommends that a sexual history be taken for all teenagers and adults at least annually.
12 Topics to consider addressing include the 5 Ps: partners, practices, past STI, protection, and pregnancy prevention. When taking a sexual history, physicians should use neutral terms (eg, partner) and avoid making assumptions about a patient's sexual behaviors, sexual orientation, or gender identity.
12
Sources of additional STI training and education include the National Network of STD Clinical Prevention Training Centers
13 and the CDC.
14 Cardea Services has a sexual history–taking toolkit, which includes a comfort scale self-assessment, sample history forms, and a pocket guide.
15
Advocating for funding for affordable STI screening and treatment programs at the state or national level is important, particularly for patients in underserved areas. Additionally, advocating for expansion of expedited partner therapy would be of benefit to potential infected partners and would help reduce the spread of STIs.
The rates of chlamydia, gonorrhea, and syphilis infections are alarmingly high. These STIs can cause grave medical consequences for affected persons, especially when the STIs are undiagnosed and untreated. It is imperative that health care professionals perform thorough sexual histories, be familiar with STI presentations, enact routine screening for STIs in sexually active patients, and provide patient education. By remaining proficient in the current diagnosis and treatment guidelines and committing to continuing education, they can play a role in reversing this alarming trend in the United States.