STD basics

STD risk factors


How do people get infected with an STD?

STDs can affect anyone of any background, lifestyle, race, ethnicity or socioeconomic status and are most often passed from one person to another through sexual activity...including genital, anal and oral sex. STD risk factors include:

  • A history of STDs
  • A history of unprotected sex
  • A new sexual partner
  • Multiple sexual partners
  • Meeting sexual partners on the Internet
  • Men who have sex with men (MSM)
  • Sexual contact with sex workers
  • Sexual contact while under the influence of alcohol or drugs
  • Illicit drug use

Due to reporting disparities and a number of other variables, there is a higher prevalence of STDs among sexually active females, teenagers, young adults, African-Americans and Hispanics...for example, women are more likely to get screened, and some ethnic/minority groups are more likely to use public clinics that report STD cases. As well, awareness of STDs and how to prevent them, and access to regular healthcare are inconsistent among populations that are disadvantaged by poverty and other social determinants...these groups may therefore be more likely to engage in risky sexual activity.

Even if you've been treated for an STD, you're not immune...you can be re-infected. That's why sexual partners should be treated at the same time so that an untreated partner still carrying the bacteria or virus doesn't re-infect the treated partner.

Last reviewed by Lisa Oldson, MD, January 2011.

Lisa Oldson, MD

STD expert

"The first thing I tell a patient about STDs is that if you're worried about one STD, you should probably worry about all STDs. In other words, if you had unprotected sex and you're worried about a possible HIV exposure, it's important to understand that hepatitis can be spread in the same fashion...ditto for chlamydia, gonorrhea, herpes and syphilis."