1. Sexually Transmitted Infections (STIs)
Overview
Sexually Transmitted Infections (STIs)
Updated October 2017

2. What are STIs?
Sexually transmitted infections (STIs) are infections passed from one person to another through sexual contact.
Vaginal, oral, or anal sex
Genital touching
An infection is when a bacteria, virus, or parasite enters and grows in or on your body.
STIs can be spread even if there are no signs or symptoms.
Some STIs are curable and others are not.
Many STDs do not show symptoms for a long time, but they can still be harmful and passed on during sex.2
References:
1. “Sexually Transmitted Infections.” Womenshealth.gov, 12 June 2017, Accessed October 2017
2. “Sexually Transmitted Diseases.” Centers for Disease Control and Prevention, Centers for Disease Control and Prevention, 4 Aug. 2016,

3. Types of STIs Bacterial Viral Parasitic Chlamydia Genital herpes
Trichomoniasis
Gonorrhea
Human papillomavirus (HPV)
Syphilis
Hepatitis (B&C)
HIV/AIDS
Human papillomavirus (HPV) accounts for majority of prevalent STIs in the United States. Most sexually active men and women will get HPV at some point in their lives. Everyone is at risk for the potential outcomes of HPV.1
It is estimated that about 79 million Americans are currently infected with HPV and about 14 million people become newly infected each year.2
Health problems related to HPV include genital warts and cervical cancer. While there is treatment for health related problems that HPV can cause, there is no treatment for the virus itself.1,2
References:
“Sexually Transmitted Diseases (STDs).” Centers for Disease Control and Prevention, Centers for Disease Control and Prevention, 26 Sept. 2017,
“Human Papillomavirus (HPV).” Centers for Disease Control and Prevention, Centers for Disease Control and Prevention, 6 Oct. 2017,

4. How Common are STIs?
CDC suggests there are more than 110 million STIs overall among men and women nationwide, including new and existing infections.
An estimated 20 million new cases in the US alone occur each year.1
Young people aged (15-24) account for 50% of all new STIs
The annual number of new infections for STI incidents among young women and men is roughly equal with young women at 51% and young men at 49%.
STIs are on the rise in the U.S. The highest number of cases of chlamydia, gonorrhea and syphilis were recorded in 2016.
1,526,658 cases of chlamydia in 20152
395,216 cases of gonorrhea in 20152
23,872 cases of syphilis in 20152
Reference:
“Sexually Transmitted Diseases (STDs).” Centers for Disease Control and Prevention, Centers for Disease Control and Prevention, 26 Sept. 2017,
“NCHHSTP AtlasPlus.” Centers for Disease Control and Prevention, Centers for Disease Control and Prevention, 30 Aug. 2017, .

5. (Incidence and Prevalence for ages 15-49)
Estimate of STIs
STI
Incidence *
Prevalence **
HPV1
14 million
79 million
Chlamydia
2.9 million
3.7 million
Trichomoniasis
1.1 million
1.6 million
Gonorrhea
820,000
270,000
Genital Herpes
776,000
24.1 million
Syphilis
55,400
117,000
Hepatitis B
19,000
422,000
Although it is difficult to know the exact number of new cases of various STIs each year (called incidence) or the total number of individuals with existing infections in the population (called prevalence), estimates accepted by the CDC are shown here. Note that human papillomavirus is the most common viral STI in terms of new cases each year. It is the primary cause of cervical cancer in women.
Chlamydia has bi-passed Trichomoniasis as the second most common new infection, as well as in prevalence.
(Incidence and Prevalence for ages 15-49)
References:
CDC Factsheet, “Incidence, Prevalence, and Cost of Sexually Transmitted Infections in the United States”, Feb 2013, retrieved from CDC website (October, 2014)
Satterwhite, et al, “Sexually Transmitted Infections Among US Women and Men: Prevalence and Incidence Estimates, 2008” Sexually Transmitted Diseases”, March 2013 – Volume 40 – Issue 3, p
* Number of new infections occurring in the population in one year
** Number of infections found in the population including those from previous years
Source: CDC website 2013.

6. Direct Medical Costs of STIs in the United States
16 Billion Dollars
81% of the total is associated with HIV infection/ 26% of new cases are in ages
HPV costs $1.7 billion / 49% of new cases in ages
Genital herpes costs $540.7 million / 45% of new cases in ages 15-24
Chlamydia costs $516.7 million / 63% of new cases in ages 15-24
Gonorrhea costs $162.1 million / 70% of new cases in ages 15-24
1. “CDC’s cost estimates reflect the lifetime direct medical cost per case of eight common STIs in the United States and do not include either indirect costs (e.g., loss of productivity) or intangible costs (e.g., pain and suffering) associated with many STIs.” 1
References:
CDC, “Incidence, Prevalence, and Cost of Sexually Transmitted Infections in the United States,” CDC website, Feb. 2013, retrieved Oct. 2014
Owusu-Edusel, et al, “The Estimated Direct Medical Cost of Selected Sexually Transmitted Infections in the United States, 2008.” Sexually Transmitted Diseases, March 2013, Volume 40 – Issue 3 – p 197 – 201
CDC, “Sexually Transmitted Infections Among Young Americans”, CDC website, July , retrieved Oct 2014. . .

7. Physical Consequences
STIs can increase the risk of getting HIV
24,000 women become infertile each year due to STIs1
Untreated infections or chlamydia can result in Pelvic Inflammatory Disease (PID) and lead to infertility.3
HPV untreated can lead to genital warts and HPV cancers.2
New cancers each year attributable to HPV2
Women 23,330
Men 16,514
References:
“Sexually Transmitted Diseases (STDs).” Centers for Disease Control and Prevention, Centers for Disease Control and Prevention, 4 Oct. 2017,
“HPV and Cancer.” Centers for Disease Control and Prevention, Centers for Disease Control and Prevention, 3 Mar. 2017,
“Sexually Transmitted Diseases (STDs).” Centers for Disease Control and Prevention, Centers for Disease Control and Prevention, 6 Oct. 2017,

8. Avoiding STIs
Consistent condom use (100%) only reduces your risk but doesn’t eliminate it.
For those who choose to be sexually active, marriage (mutually faithful, life-long relationship with an uninfected sexual partner) is the healthiest choice
For unmarried individuals, sexual abstinence is the only practical and certain way to avoid STIs.