Foreword, Preface, & Acronyms


STDs have long been an underestimated opponent in the public health battle. A 1997 Institute of Medicine (IOM) report described STDs as “hidden epidemics of tremendous health and economic consequence in the United States,” and stated that the “scope, impact, and consequences of STDs are under recognized by the public and healthcare professionals.”1 Since well before this report was published, and two decades later, those facts remain unchanged.

Yet not that long ago, gonorrhea rates were at historic lows, syphilis was close to elimination, and we were able to point to advances in STD prevention, such as better chlamydia diagnostic tests and more screening, contributing to increases in detection and treatment of chlamydial infections. That progress has since unraveled. The number of reported syphilis cases is climbing after being largely on the decline since 1941, and gonorrhea rates are now increasing. This is especially concerning given that we are slowly running out of treatment options to cure Neisseria gonorrhoeae. Many young women continue to have undiagnosed chlamydial infections, putting them at risk for infertility.

Half of STDs are among young people aged 15 to 24 years.2 These infections can lead to long-term health consequences, such as infertility; they can facilitate HIV transmission; and they have stigmatized entire subgroups of Americans. Beyond the impact on an individual’s health, STDs are also an economic drain on the US healthcare system, costing billions annually.3 To complicate the matter, STD public health programs are increasingly facing challenges and barriers in achieving their mission.

It is imperative that federal, state, and local programs employ strategies that maximize long-term population impact by reducing STD incidence and promoting sexual, reproductive, maternal, and infant health. The resurgence of syphilis, and particularly congenital syphilis, is not an arbitrary event, but rather a symptom of a deteriorating public health infrastructure and lack of access to health care. It is exposing hidden, fragile populations in need that are not getting the health care and preventive services they deserve. This points to our need for public health and health care action for each of the cases in this report, as they represent real people, not just numbers.

We also need to modernize surveillance to move beyond counting only those cases in persons who have access to diagnosis and treatment, to develop innovative strategies to understand the burden of disease in those who may not access care, and to improve our surveillance systems to collect the information needed to target prevention activities. Further, it will be important for us to measure and monitor the adverse health consequences of STDs, disease, ectopic pregnancy, infertility, HIV, congenital syphilis, and neonatal herpes.

It is my hope that in future years, we will be reporting on progress, instead of more health inequity in our society. This is our challenge and our call to effectively respond to the information shared in this report.

Gail Bolan, M.D.
Director, Division of STD Prevention
National Center for HIV/AIDS, Viral Hepatitis, STD, and TB Prevention
US Centers for Disease Control and Prevention


1. Eng TR, Butler WT, editors; Institute of Medicine (US). Summary: The hidden epidemic: Confronting sexually transmitted diseases. Washington (DC): National Academy Press;1997.

2. Satterwhite CL, Torrone E, Meites E, et al. Sexually transmitted infections among US women and men: Prevalence and incidence estimates, 2008. Sex Transm Dis. 2013;40(3):187–193. DOI:10.1097/OLQ.0b013e318286bb53.

3. Owusu-Edusei K Jr, Chesson HW, Gift TL, et al. The estimated direct medical cost of selected sexually transmitted infections in the United States, 2008. Sex Transm Dis. 2013;40(3):197–201. DOI: 10.1097/OLQ.0b013e318285c6d2.


Sexually Transmitted Disease Surveillance 2018 presents statistics and trends for STDs in the United States through 2018. This annual publication is intended as a reference document for policy makers, program managers, health planners, researchers, and others who are concerned with the public health implications of these diseases. The figures and tables in this edition supersede those in earlier publications of these data.

The surveillance information in this report is based on the following sources of data: (1) notifiable disease reporting from state and local STD programs; (2) projects and programs that monitor STDs in various settings, including the National Job Training Program, the STD Surveillance Network, and the Gonococcal Isolate Surveillance Project; and (3) national surveys and other data collection systems implemented by federal and private organizations.

Four STDs are nationally notifiable, chlamydia, gonorrhea, syphilis, and chancroid, and state and local STD control programs provide CDC with case reports for these conditions. These case reports are the data source for many of the figures and most of the statistical tables in this publication; however, it is important to note that these case reports reflect only a portion of STDs occurring in the US population. First, other common STDs, such as human papillomavirus (HPV) and herpes simplex virus (HSV) are not nationally notifiable diseases. Additionally, STDs are often asymptomatic and may not be diagnosed; therefore, case report data underestimate the number of infections that occurred.

In January 2018, a revised case definition for syphilis went into effect, including changing the stage previously termed “early latent syphilis” to “syphilis, early non-primary non-secondary”. This change in terminology more accurately reflects this stage of infection, as neurologic symptoms, including ocular syphilis, can occur at this stage. Additionally, the stages of “late latent syphilis” and “late syphilis with clinical manifestations” were removed and “syphilis, unknown duration or late” was added. More information on syphilis morbidity reporting and the current case definition can be found in Appendices A and C of this report.

Sexually Transmitted Disease Surveillance 2018 consists of four sections: the National Profile, the Special Focus Profiles, the Tables, and the Appendix. The National Profile section contains figures that provide an overview of STD morbidity in the United States. The accompanying text identifies major findings and trends for selected STDs. The Special Focus Profiles section contains figures and text that describe STDs in selected populations that are a focus of national and state prevention efforts. The Tables section provides statistical information about STDs at county, metropolitan statistical area, regional, state, and national levels. The Appendix includes information on how to interpret the STD surveillance data used to produce this report, as well as information about Healthy People 2020 STD objectives and progress toward meeting these objectives, Congressional Budget Justification goals and progress toward meeting these goals, and STD surveillance case definitions.

Any comments and suggestions that would improve future publications are appreciated and should be sent to:

Director, Division of STD Prevention
National Center for HIV/AIDS, Viral Hepatitis, STD, and
TB Prevention
Centers for Disease Control and Prevention
1600 Clifton Road NE, Mailstop US12–2
Atlanta, Georgia 30329–4027

Guide to Acronyms
This is a table caption for compliance.
ACIP Advisory Committee on Immunization Practices
AI/AN American Indians/Alaska Natives
ARLN Antibiotic Resistance Laboratory Network
APC Annual percent change
AS American Samoa
CDC Centers for Disease Control and Prevention
CI confidence interval
CIA chemiluminescence immunoassay
CIN2+ cervical intraepithelial neoplasia grades 2 and 3
CS congenital syphilis
CSF cerebrospinal fluid
CSTE Council of State and Territorial Epidemiologists
CT chlamydia
ED emergency department
EIA enzyme immunoassay
EP ectopic pregnancy
FDA Food and Drug Administration
FTA-ABS fluorescent treponemal antibody absorbed
GC gonorrhea
GISP Gonococcal Isolate Surveillance Project
GU Guam
HCUP Healthcare Cost and Utilization Project
HD health department
HEDIS Healthcare Effectiveness Data and Information Set
HMOs health maintenance organizations
HIV human immunodeficiency virus
HP2020 Healthy People 2020
HPV human papillomavirus
HSV herpes simplex virus
HSV-1 herpes simplex virus type 1
HSV-2 herpes simplex virus type 2
IHC immunohistochemistry
MHA-TP microhemagglutination assay for antibody to Treponema pallidum
MICs minimum inhibitory concentrations
MP Northern Mariana Islands
MPC mucopurulent cervicitis
MSAs metropolitan statistical areas
MSM gay, bisexual, and other men who have sex with men
MSMW men who have sex with both men and women
MSW men who have sex with women only
NAATs nucleic acid amplification tests
NCHHSTP National Center for HIV/AIDS, Viral Hepatitis, STD, and TB Prevention
NCHS National Center for Health Statistics
NHOPI Native Hawaiians/Other Pacific Islanders
NDTI National Disease and Therapeutic Index
NEDSS National Electronic Disease Surveillance System
NETSS National Electronic Telecommunications System for Surveillance
NGU nongonococcal urethritis
NHANES National Health and Nutrition Examination Survey
NJTP National Job Training Program
NNDSS National Notifiable Diseases Surveillance System
OMB Office of Management and Budget
P&S primary and secondary
PCR polymerase chain reaction
PID pelvic inflammatory disease
PR Puerto Rico
RPR rapid plasma reagin
SSuN STD Surveillance Network
STD sexually transmitted disease
STI sexually transmitted infection
TP-PA T. pallidum particle agglutination
VDRL Venereal Disease Research Laboratory
VI Virgin Islands
WBC white blood cell