Increased Methamphetamine, Injection Drug, and Heroin Use Among Women and Heterosexual Men with Primary and Secondary Syphilis - United States, 2013-2017

Weekly / February 15, 2019 / 68(6);144–148

Sarah E. Kidd, MD1; Jeremy A. Grey, PhD1; Elizabeth A. Torrone, 
PhD1; Hillard S. Weinstock, MD1 (View author affiliations)

View suggested citation

Summary
What is already known about this topic?

During 2013–2017, the primary and secondary (P&S) syphilis rate 
increased 72.7% nationally and 155.6% among women.

What is added by this report?

During 2013–2017, reported methamphetamine, injection drug, and 
heroin use increased substantially among women and heterosexual men 
with P&S syphilis.

What are the implications for public health practice?

Heterosexual syphilis transmission and drug use, particularly 
methamphetamine use, are intersecting epidemics. Collaboration 
between sexually transmitted disease control programs and substance 
use disorder services providers will be essential to address recent 
increases in heterosexual syphilis transmission. Linking syphilis 
patients with substance use disorders to behavioral health services 
and providing syphilis screening for persons receiving substance use 
disorder services are needed to address these co-occurring 
conditions.

During 2013–2017, the national annual rate of reported primary and 
secondary (P&S) syphilis cases in the United States increased 72.7%, 
from 5.5 to 9.5 cases per 100,000 population (1). The highest rates 
of P&S syphilis are seen among gay, bisexual, and other men who have 
sex with men (collectively referred to as MSM) (2), and MSM 
continued to account for the majority of cases in 2017 (1). However, 
during 2013–2017, the P&S syphilis rate among women increased 155.6% 
(from 0.9 to 2.3 cases per 100,000 women), and the rate among all 
men increased 65.7% (from 10.2 to 16.9 cases per 100,000 men), 
indicating increasing transmission between men and women in addition 
to increasing transmission between men (1). To further understand 
these trends, CDC analyzed national P&S syphilis surveillance data 
for 2013–2017 and assessed the percentage of cases among women, men 
who have sex with women only (MSW), and MSM who reported drug-
related risk behaviors during the past 12 months. Among women and 
MSW with P&S syphilis, reported use of methamphetamine, injection 
drugs, and heroin more than doubled during 2013–2017. In 2017, 16.6% 
of women with P&S syphilis used methamphetamine, 10.5% used 
injection drugs, and 5.8% used heroin during the preceding 12 
months. Similar trends were seen among MSW, but not among MSM. These 
findings indicate that a substantial percentage of heterosexual 
syphilis transmission is occurring among persons who use these 
drugs, particularly methamphetamine. Collaboration between sexually 
transmitted disease (STD) control programs and partners that provide 
substance use disorder services will be important to address recent 
increases in heterosexual syphilis.

P&S syphilis case report data were extracted from the National 
Notifiable Diseases Surveillance System, the system through which 
CDC receives syphilis and other notifiable sexually transmitted 
disease data from all 50 states and the District of Columbia. P&S 
syphilis case report data include demographic information and also 
risk factor information, such as information about sex partners and 
drug use within the past 12 months, which is obtained through case 
interviews or investigation by the local health department.


During 2013–2017, the percentage of persons with P&S syphilis who 
reported methamphetamine use, sex with a person who injects drugs, 
injection drug use, or heroin use within the past 12 months more 
than doubled among women and MSW (Table 1). The percentage of 
persons with P&S syphilis reporting methamphetamine use increased 
from 6.2% to 16.6% among women, and from 5.0% to 13.3% among MSW, 
but decreased from 9.2% to 8.0% among MSM. The percentage of persons 
with P&S syphilis reporting sex with a person who injects drugs 
increased from 5.5% to 12.4% among women and from 3.6% to 9.3% among 
MSW, but increased only slightly among MSM (from 4.3% to 5.2%). 
Injection drug use increased from 4.0% to 10.5% among women with P&S 
syphilis and from 2.8% to 6.3% among MSW, but remained stable at 
3.5% among MSM. Heroin use increased from 2.1% to 5.8% among women 
with P&S syphilis and from 0.8% to 2.7% among MSW, but remained 
relatively stable (increased from 0.7% to 0.8%) among MSM.

Among women with P&S syphilis, increases in methamphetamine use, sex 
with a person who injects drugs, injection drug use, and heroin use 
were observed in every region of the United States (Table 2). Among 
MSW with P&S syphilis, the increase in sex with a person who injects 
drugs was observed in every region, and the increases in 
methamphetamine, injection drug, and heroin use occurred in all 
regions except the Northeast (Table 3). Although trends were 
generally similar across regions, the prevalence of these behaviors 
among women and MSW with P&S syphilis varied considerably by region. 
In 2017, the percentages of both women and MSW reporting these 
behaviors were highest in the West and lowest in the Northeast. In 
the West, methamphetamine use during the past 12 months was reported 
by 34.8% of women with P&S syphilis and 25.0% of MSW with P&S 
syphilis. In addition, 22.6% of women with P&S syphilis in the West 
had sex with a person who injects drugs, and 21.2% used injection 
drugs (Table 2). In contrast, <3% of women or MSW with P&S syphilis 
in the Northeast reported these behaviors in 2017 (Table 2) (Table 
3). Additional data on other behaviors and characteristics reported 
among persons with P&S syphilis, such as number of sex partners, HIV 
status, and other drug use data, are available online in a 
supplemental syphilis surveillance report 
(https://www.cdc.gov/std/stats17/syphilis2017/).

Top

Discussion
Since reaching a historic low in the United States in 2000–2001, the 
annual national rate of reported P&S syphilis cases has increased, 
and the rate in 2017 (9.5 per 100,000 population) was the highest 
reported since 1993 (1). Until 2013, the increase was primarily 
among MSM, and rates of P&S syphilis among women remained low and 
relatively stable (3). However, during 2013–2017, the P&S syphilis 
rate increased among both men and women (1). This report 
demonstrates that, during this same period, the prevalences of 
methamphetamine use, sex with a person who injects drugs, injection 
drug use, and heroin use within the past 12 months more than doubled 
among MSW and women with P&S syphilis, but not among MSM with P&S 
syphilis.

These findings indicate that a substantial percentage of 
heterosexual syphilis transmission is occurring among persons who 
use methamphetamine, inject drugs or have sex with persons who 
inject drugs, or who use heroin, and that heterosexual syphilis and 
drug use are intersecting epidemics. A linkage between heterosexual 
syphilis and drug use has been observed previously. In the late 
1980s and early 1990s, increases in heterosexual syphilis were 
associated with crack cocaine use (4,5). Drug use, particularly use 
of methamphetamine and injection drugs, is associated with sexual 
behaviors that increase the risk for acquiring syphilis and other 
sexually transmitted diseases, including having multiple sex 
partners or concurrent sexual partnerships, inconsistent condom use, 
and exchange of sex for drugs or money (6–8). In addition, among 
persons who use drugs, stigma and mistrust of the health care system 
along with other social determinants of health (e.g., unstable 
housing, poverty, incarceration, and lack of health insurance or a 
medical home) might contribute to decreased health care utilization 
and reluctance or inability to identify and locate sex partners, 
resulting in delays in diagnosis and treatment (4,5). These 
complications likely contribute to increasing syphilis incidence in 
communities and pose significant challenges to syphilis prevention 
and control efforts.

Pilot projects have demonstrated the feasibility and benefit of 
implementing substance use disorder interventions in STD clinics 
(9,10). STD programs should consider partnering with substance use 
disorder prevention and treatment programs and other organizations 
that provide services to persons who use drugs in the local 
community. Heterosexual networks and sexual risk behaviors are 
linked with drug use, and STD programs should work with substance 
use programs to facilitate referrals to substance use disorder 
treatment services when needed and to integrate STD and substance 
use disorder prevention and treatment services when possible. 
Substance use disorder programs and other community organizations 
that provide services to persons who use drugs can also provide 
opportunities for STD prevention and case-finding, through promotion 
of safer sex practices, condom distribution, and testing for 
syphilis and other sexually transmitted infections.

The findings in this report are subject to at least three 
limitations. First, syphilis case report data do not include data on 
opioid use other than heroin, so it was not possible to assess 
nonheroin opioid use among persons with syphilis. Second, cases with 
incomplete data on variables of interest were excluded from this 
analysis. Overall, depending on the year and variable, 18%–25% of 
reported cases of P&S syphilis among women, MSW, and MSM were 
missing data on methamphetamine use, sex with a person who injects 
drugs, injection drug use, or heroin use during 2013–2017. If 
persons whose records had missing data were less likely to have a 
risk factor, it is possible that this analysis overestimated the 
prevalence of these risk factors among persons with syphilis. 
Finally, because of stigma surrounding these risk behaviors, some 
persons might have been reluctant to disclose drug use, leading to 
misclassification and underestimates of the true percentage of 
persons with syphilis who used these drugs.

The recent increases in heterosexual syphilis, together with the 
concurrent increases in percentage of persons with P&S syphilis 
reporting methamphetamine use, sex with a person who injects drugs, 
injection drug use, and heroin use, are causes for concern. 
Heterosexual syphilis and drug use, particularly methamphetamine 
use, are connected and interrelated epidemics in the United States. 
Collaboration between STD control programs and partners that provide 
services for persons with substance use disorders will be essential 
to address recent increases in heterosexual syphilis and link 
patients to clinical and prevention services.

Top