Drug Use Among Women and Heterosexual Men With Syphilis, 2013–2017

From 2013 to 2017, the U.S. rate of primary and secondary (P&S) syphilis rose 72.7%, from 5.5 to 9.5 cases per 100,000 people — the highest since 1993. Gay, bisexual and other men who have sex with men (MSM) have the highest rates and still made up most cases in 2017. But the rate among women rose 155.6% (from 0.9 to 2.3 per 100,000) and among all men 65.7% (from 10.2 to 16.9), a sign that transmission between men and women was growing too. CDC looked at whether drug use might help explain the rise.

The data

CDC analyzed P&S syphilis case reports from all 50 states and the District of Columbia. Reports include information, gathered by local health departments, on sex partners and drug use in the previous 12 months. Men were classed as MSM if they had any male partner in that period, and as men who have sex with women only (MSW) otherwise.

Findings

Among women and MSW with P&S syphilis, reported use of methamphetamine, injection drugs and heroin, and sex with a person who injects drugs, more than doubled from 2013 to 2017. MSM did not follow the same pattern.

By region:

• Among women, all four behaviors rose in every region. Among MSW, sex with a person who injects drugs rose everywhere, and the other three rose everywhere except the Northeast.
• Levels varied widely. In 2017 they were highest in the West, where 34.8% of women and 25.0% of MSW with P&S syphilis reported methamphetamine use, and 22.6% of women had sex with someone who injects drugs and 21.2% injected drugs. In the Northeast, fewer than 3% of women or MSW reported these behaviors.

Intersecting epidemics

Syphilis hit a historic low in 2000–2001. Until 2013 the rise afterward was mainly among MSM, with rates among women low and steady. These findings suggest that a substantial share of heterosexual syphilis transmission is occurring among people who use methamphetamine, inject drugs or have sex with people who inject drugs, or use heroin.

This echoes the late 1980s and early 1990s, when a rise in heterosexual syphilis was tied to crack cocaine. Drug use — particularly methamphetamine and injection drugs — is linked to sexual behaviors that raise the risk of syphilis and other STDs: multiple or overlapping partners, inconsistent condom use, and trading sex for drugs or money. Stigma, mistrust of health care, unstable housing, poverty, incarceration and lack of insurance may also mean less use of health care and more difficulty finding sex partners for treatment, delaying diagnosis and treatment.

What the authors recommended

• STD programs should partner with substance use prevention and treatment programs and other organizations serving people who use drugs, refer patients to substance use treatment, and integrate services where possible. Pilot projects have shown substance use interventions can work in STD clinics.
• Substance use programs and community organizations can support STD prevention and case-finding through safer-sex promotion, condom distribution, and testing for syphilis and other sexually transmitted infections.

Limitations: case reports don't capture opioid use other than heroin; 18%–25% of cases were missing drug-use data, which could lead to overestimates if people with missing data were less likely to use drugs; and stigma may have led some people not to disclose drug use.

Sources

• Kidd SE, Grey JA, Torrone EA, Weinstock HS. "Increased Methamphetamine, Injection Drug, and Heroin Use Among Women and Heterosexual Men with Primary and Secondary Syphilis — United States, 2013–2017." Morbidity and Mortality Weekly Report 68(6), Centers for Disease Control and Prevention.