STD epidemic in US carries staggering human, economic costs

With rates of sexually transmitted diseases at an all-time high in the United States, the need for more screening as well as better treatment and prevention methods, especially for those at highest risk, has reached a critical point.

“We have reached a decisive moment for the nation,” Jonathan H. Mermin, MD, MPH, director of the CDC’s National Center for HIV/AIDS, Viral Hepatitis, STD, and TB Prevention, said in a press release. “STD rates are rising, and many of the country’s systems for preventing STDs have eroded. We must mobilize, rebuild and expand services — or the human and economic burden will continue to grow.”

According to the CDC’s annual Sexually Transmitted Disease Surveillance Report, the three nationally reported STDs hit a record high of roughly 1.9 million cases in 2015. From 2014 to 2015, the number of chlamydia cases rose 5.9% to more than 1.5 million, and the number of gonorrhea cases increased 12.8% to nearly 400,000 cases; the largest increase was seen in primary and secondary syphilis, which rose 19% to almost 24,000 cases.

A recent overall estimate of the prevalence of STDs, which includes new and existing infections, suggests that there are 110 million cases nationwide. This prevalence data included the three reported STDs, as well as hepatitis B virus, herpes simplex virus type 2 (HSV-2), HIV, HPV and trichomoniasis.

Photo courtesy of Bryan Meltz, Emory University

Infectious Disease News spoke with leading experts about the reasons behind the record-high cases of STDs in the U.S., the people who are at greatest risk and what is being done to reverse the epidemic.

Reasons for the epidemic

The causes of this epidemic are multifactorial. One of the primary contributors relates to infrastructure, according to Edward W. Hook III, MD, professor of medicine, epidemiology and microbiology at the University of Alabama at Birmingham.

“The number of dedicated sexually transmitted disease clinics in the nation is decreasing, and patients don’t have other access [to care],” Hook told Infectious Disease News.

Indeed, budget cuts have forced the closure of more than 20 state and local health department STD clinics in 1 year alone, according to the CDC.

Access to STD care has been somewhat hampered by the Affordable Care Act as well. A key goal of the ACA, which President Donald J. Trump and Republican Congressional leaders have pledged to “repeal and replace,” was that more people would be seen by their primary care physician — “a laudable and appropriate goal,” Hook said. “There are millions more people in care than there used to be.” However, the wait time for an appointment can stretch into weeks, delaying treatment. “That obviously is not going to work,” he added.

The “Tinder effect”

Compounding the problem of STDs in the U.S. is the “Tinder effect.” Dating apps like Tinder have made it easier for people to meet and have multiple sexual exposures, which can lead to an increase in STDs, according to Peter Chin-Hong, MD, professor of medicine at the University of California, San Francisco School of Medicine, and an Infectious Disease News Editorial Board member.

Furthermore, pre-exposure prophylaxis, while an effective measure for halting the spread of HIV infections among high-risk populations, may give people a false sense of security and increase risky sexual behavior — a phenomenon known as risk compensation. “There’s no culture of condom sex because you’re not going to get HIV,” Chin-Hong said.

Another underlying cause of the epidemic, and one that continues to hinder efforts to control STDs, is “the shroud of stigma, shame and anxiety,” affecting health care providers and patients alike, according to Hook.

“That leads to patients being reticent to acknowledge that they’ve got problems, overlooking problems or attributing them to other causes; and providers perhaps not doing quite as much testing as they could or even as is recommended,” he said.

At-risk populations

Certain populations are more at risk for contracting STDs than others. Each year, Americans aged 15 to 24 years account for half of new STD cases, according to Eloisa Llata, MD, a medical epidemiologist in the CDC’s Division of STD Prevention.

“Young people face unique barriers to accessing prevention services, including confidentiality concerns, limited access to health care (ie, no insurance or transportation), discomfort or embarrassment in discussing risk behaviors,” Llata said. “And many have multiple sex partners.”

Men who have sex with men (MSM) are another vulnerable population, accounting for many of the new gonorrhea and primary and secondary syphilis infections. MSM may also be at higher risk for antibiotic-resistant gonorrhea.

Women are at risk, too. Syphilis diagnoses climbed by more than 27% from 2014 to 2015, and congenital syphilis cases rose 6%, according to CDC data.

Often these women have been put at risk, not by their own behavior, but by that of their sexual partners. “Some of our own research, for instance, suggests that if you look at the most common sexually transmitted infection — chlamydial infections — the majority of women who have chlamydial infections report only having a single sexual partner in the past 6 months or year, and yet they are infected,” Hook said.

Male health is often overlooked in the U.S., and that contributes to the problem as well.

“In our nation, we have no strategic plan for men’s health,” Hook said. Women enter the health care system once they start menstruating, where they have access to STD screening, vaccinations, blood pressure screening, etc. “Whereas for men, between their last school sports physical and the onset of chest pain, they don’t really see doctors much except for trauma and acute injuries,” he added.

Economic, human costs

The economic burden of STDs is huge: These infections represent nearly $16 billion dollars in lifetime direct medical costs, according to Llata.

Prevention, although still expensive, is a better bargain. “If you think about the prevention budget, it’s really a fraction of that,” Chin-Hong said. “It’s about $94 million a year, which sounds like a lot, but it pales in comparison to the amount of money [spent] treating [STDs].”

The human costs can also be staggering. Because of the stigma that lingers around an STD diagnosis, there is “damage to both personal self-perception, to relationships and the like,” Hook said. “I think testing causes a lot of anxiety and diagnosis causes a great deal of problems.”

If left untreated, STDs can cause significant, sometimes long-term health problems. For instance, chlamydia can cause infertility, and syphilis can lead to miscarriage, stillbirth, blindness or stroke.

“The problem with syphilis is that at its early stage, if you don’t know you have it, which is most people because it’s asymptomatic in early stages, they can progress to really devastating consequences, like neurological deficits, heart disease, strokes, etc.,” Chin-Hong said.

“STDs are significant,” said Carlos del Rio, MD, professor of medicine at Emory University School of Medicine. “They may not necessarily cause mortality, but they certainly cause morbidity.”

Most available treatments are effective

The news is not all gloom and doom: most STDs are treatable. “The good news is that chlamydia, gonorrhea and syphilis are curable; widespread testing and treatment work,” Llata said. “But the new numbers make it clear that many Americans are not getting the preventive services they need.”

Certain infections are easier to treat than others. Early-stage syphilis is treatable with penicillin. Azithromycin is effective against chlamydia, according to Chin-Hong. Among the viral infections, HSV is easy to treat. HPV is a challenge to treat but is preventable with a vaccine. And then there is gonorrhea.

“Gonorrhea has always been a wily bug,” Chin-Hong said. The pathogen has become resistant to nearly every treatment available.

Specter of untreatable gonorrhea

In their study, Thomas E. Herchline, MD, of Wright State University, and colleagues saw a marked increase in gonorrhea resistance to ciprofloxacin and reduced sensitivity to azithromycin. They analyzed isolates from the Public Health – Dayton and Montgomery County STD Clinic in Dayton, Ohio, which sees about 10,000 cases annually. In 1996, the researchers found no ciprofloxacin-resistant isolates. That number jumped to 15.7% in 2016. Their testing has also revealed significantly reduced susceptibility to azithromycin: In 2015, 1.9% of isolates had reduced sensitivity; by 2016, that number climbed to 5.9%.

Because of drug resistance, the CDC no longer recommends fluoroquinolones as a treatment option for gonorrhea, leaving cephalosporins as the last effective class of antibiotics to treat these infections.

“As we’re seeing multidrug-resistant gonorrhea emerging, the possibility of untreatable gonorrhea is real,” del Rio said.

Researchers are searching for ways to battle this looming threat. Investigators at the CDC are conducting genome-sequencing studies to help find new drugs. To date, they have sequenced more than 2,000 genomes from gonococcal strains with various resistance profiles worldwide. As this work continues, researchers hope to identify which genetic mutations cause resistance, develop molecular tests to detect it and upload genetic sequences into public databases, according to the CDC.

Currently, there is only one effective cure for gonorrhea, a treatment that requires two agents: oral azithromycin and injectable ceftriaxone.

“In some places ... there are reports of people who failed even that treatment,” Chin-Hong said.

Last year, lab tests identified the first cluster of gonorrhea cases that demonstrated decreased sensitivity to the combination therapy, according to the Hawaii State Department of Health. Isolates from seven patients showed azithromycin resistance at much higher levels than those typically seen in the United States. Isolates from five patients also showed reduced susceptibility to ceftriaxone. All patients were successfully treated with the combination therapy; no further cases have been detected since May 2016.

Growing resistance takes the hunt for new agents to a critical level. Currently, there are limited options in the pipeline. Hook said he is aware of about three new potential agents for gonorrhea.

“There are people who are beginning to evaluate new drugs and consider their use,” Hook said. “Unfortunately, that means those drugs are all at least a year or two, or even more, away from hitting the streets.”

The single-dose oral therapy ETX0914 has shown promise against gonorrhea. In a randomized, phase 2 study, researchers compared a 2-g or 3-g dose of ETX0914 with a 500-mg dose of ceftriaxone in 179 patients aged 18 to 53 years.

All patients in the 3-g dose ETX0914 group (n = 47) and 98% of patients in the 2-g dose group were cured (n = 48); all patients assigned to ceftriaxone were cured as well (n = 21). Side effects, mostly gastrointestinal, were seen in 12% of patients assigned to ETX0914.

Screening a key weapon

Screening is a critical tool in the fight against STDs; however, there are barriers, according to Hook. With STD clinics closing, access to testing is a problem. Moreover, stigma keeps many patients from getting tested. Some health care providers “make incorrect assumptions that their patients, if you’ll forgive this sort of generalization, are not the kind of person who might get an STI,” Hook said.

For primary care physicians, time constraints may inhibit their willingness to test. “Primary care providers are very busy and a have a long list of recommended screening that’s supposed to be done,” Hook said. “So, they have to weigh what’s the highest priority.”

Making STD screening simpler may be one answer to some of these problems. Currently, urine and/or swab testing is available for chlamydia and gonorrhea. “We have the tools,” Hook said. “I think many providers are not aware of them.”

Hook’s facility is part of the CDC’s national network of STD training centers to educate clinicians about STDs. “Unfortunately, there is a larger need than there is the ability to do it,” he said.

Currently, the CDC offers the following screening recommendations:

• at least one lifetime HIV test for all adults and adolescents;
• annual chlamydia and gonorrhea screening for sexually active women aged 25 years or younger and older women with risk factors such as new or multiple sex partners or a sex partner with an STD;
• screening for syphilis, HIV, chlamydia and HBV in all pregnant women, and gonorrhea screening for at-risk pregnant women, at their first prenatal visit;
• annual trichomoniasis testing for all HIV–infected women;
• annual syphilis, chlamydia, gonorrhea and HIV screening for all sexually active MSM, and more frequent testing for MSM who have multiple or anonymous sexual partners (ie, 3- to 6-month intervals); and
• annual HIV screening for anyone who has unsafe sex or shares injection drug equipment.

Prevention is the best cure

Clearly, preventing STDs is paramount, but right now that can be a challenge. “I think we have a very low STD literacy rate in general in society,” Chin-Hong said. “I think many people just don’t know their risk or where to go to get tested.”

Identification is one important step, according to Chin-Hong. “If you are asymptomatic and you don’t know it, and you continue to have unprotected sex, you’re going to expand your circle of people around you who have the infection. If you can identify the one person, trace contacts, and then you can stop it like that.”

Prevention efforts should get creative, using available technology to achieve greater reach, he said. Phone apps may be one way to promote sexual health. Additionally, electronic health records can prompt physicians to test patients at risk.

“If Target can figure out who is pregnant because they’re buying certain products, then I think we can figure out who is at risk for STDs,” Chin-Hong said.

Vaccines are also an important part of prevention efforts. Studies have shown that partner-to-partner transmission of HSV, an incurable infection, can be prevented with suppressive acyclovir, according to Chin-Hong.

Hook noted that the HPV vaccine prevents more than 90% of infections. “In other countries, like Australia, the HPV vaccine has been shown to actually reduce the incidence and occurrence of abnormal Pap smears,” he said.

The HBV vaccine is also highly effective, according to Hook.

Nationwide, there are groups who support abstinence as an STD prevention method, whereas others advocate condom use. “I fear the cat is out of the bag with this generation,” Chin-Hong said, adding that younger people are both less educated about safe sex practices and lack access to condoms.

Additionally, improving health care provider literacy is crucial to the success of prevention efforts. “Many providers don’t know how to easily test and identify treatable STDs in the clinic,” Chin-Hong said.

The CDC is bolstering prevention efforts by supporting state and local health departments though disease surveillance programs, contact tracing and health promotion, according to Llata. The agency will maintain its STD treatment guidelines and related provider resources to ensure effective patient care. Finally, the CDC will continue its efforts to monitor disease, track trends and target resources, and remain vigilant for signs of emerging drug resistance, she said.

All hands on deck

The solution to the skyrocketing STD rates must involve all health care constituents, according to Llata. Health care providers should integrate screening into care, for instance during prenatal visits for routine check-ups. People must remove the stigma of STDs by talking about them openly, getting regular testing and reducing risk “by using condoms or practicing mutual monogamy if sexually active,” she added. Moreover, young people need “safe and effective ways to access needed information and services.” Finally, state and local health departments should “continue to direct resources to people hardest hit by the STD epidemic and work with community and health care partners to maximize their impact,” she said.

The ID specialist has a significant and multidimensional role in fighting the STD epidemic, according to Chin-Hong. “One is improving provider literacy, and I think not just talking about the infectious disease aspects, but talking about the systems aspects,” he said. ID specialists can help streamline workflow to ensure that testing kits are available, and that the electronic medical record systems prompt screening in at-risk patients.

ID physicians can be advocates for federal funding, especially for under-the-radar infections, such as HPV, HSV and trichomonas, according to Chin-Hong. Also, they can push for more drug development, and not just for gram-negative infections. “We may understand the impact, not only the medical impact, but the societal impact as well,” he said. “We’ve learned a lot of lessons from HIV in terms of stigma, so I feel we can apply that framework here as well.” – by Colleen Owens

• References:
• CDC. AMD Projects: Treating the Antimicrobial-Resistant Gonorrhea Threat. https://www.cdc.gov/amd/project-summaries/treating-gonorrhea-threat.html. Accessed January 24, 2017.
• CDC. Combating the threat of antibiotic-resistant gonorrhea. https://www.cdc.gov/std/gonorrhea/arg/carb.htm. Accessed January 22, 2017.
• CDC. Incidence, prevalence, and cost of sexually transmitted infections in the United States. https://www.cdc.gov/std/stats/. Accessed January 14, 2017.
• CDC. Sexually transmitted surveillance report. 2015. https://www.cdc.gov/std/stats15/default.htm. Accessed January 14, 2017.
• CDC. STD & HIV Screening Recommendations. https://www.cdc.gov/std/prevention/screeningreccs.htm. Accessed January 24, 2017.
• Herchline T. Abstract LB-8. Presented at: IDWeek; Oct. 26-30, 2016; New Orleans.
• Seña AC, et al. Abstract 1308. Presented at: IDWeek; Oct. 26-30, 2016; New Orleans.

• For more information:
• Peter Chin-Hong, MD, can be reached at UCSF School of Medicine, 513 Parnassus Ave., Med Sci, San Francisco, CA 94143; email: peter.chin-hong@ucsf.edu.
• Edward W. Hook III, MD, can be reached at the University of Alabama at Birmingham, Tinsley Harrison Tower 215, 1900 University Blvd., Birmingham, AL 35294-0006; email: ehook@uab.edu.
• Eloisa Llata, MD, can be reached at nchhstpmediateam@cdc.gov.
• Carlos del Rio, MD, can be reached at The Rollins School of Public Health of Emory University, 1518 Clifton Rd. NE. Claudia N. Rollins Bldg 7; email: cdelrio@emory.edu.

Disclosures: Chin-Hong, Hook and Llata report no relevant financial disclosures. del Rio is the primary investigator and laboratory director of the Atlanta Regional Laboratory of the CDC-funded Gonococcal Isolate Resistance Program.