What are the risk factors for chlamydia?

Risk Factors for Chlamydia Infection

Young age (under 25 years) and sexual activity are the most significant risk factors for chlamydia infection, with women under 25 being more than 5 times as likely to be infected compared to women over 30. 1

Primary Risk Factors

Demographic Risk Factors

• Age:

  • Women ≤24 years of age 1
  • Adolescents and young adults 2

• Race/Ethnicity:

  • Higher prevalence rates in African-American and Hispanic populations 1

• Gender:

  • Women are at higher risk for serious complications 3

Sexual Behavior Risk Factors

• Multiple sexual partners:

  • Having new or multiple sexual partners 1
  • Three or more lifetime sexual partners (2.57 times increased risk) 4
  • Two or more sexual partners in the past year 5

• Partner-related factors:

  • Having a partner who has other concurrent partners 1
  • Having a partner with chlamydia infection 1

• Inconsistent condom use 1

• Commercial sex work 1

• History of STIs:

  • Previous chlamydial infection 1
  • History of other sexually transmitted infections 1

Additional Risk Factors

• Travel abroad combined with multiple sexual partners (particularly in teenagers) 6

• Non-monogamous relationships (not being in a mutually monogamous relationship with an uninfected partner) 1

• Drug use 1

High-Risk Settings

Certain settings are associated with higher prevalence of chlamydia:

• Adolescent clinics 1
• Correctional facilities 1
• STD clinics 1

Risk Patterns

Research using latent class analysis has identified distinct patterns of risk:

• Individuals with multiple sexual partners are significantly more likely to engage in other high-risk behaviors 2, 5
• Men with high-risk sexual behavior patterns are more likely to test positive for chlamydia 2

Clinical Implications

Understanding these risk factors is crucial because:

1. Screening recommendations are based on risk factors:

   • All sexually active women ≤25 years should be screened annually 1
   • Women >25 years with risk factors should be screened 1
   • Pregnant women with risk factors should be screened at first prenatal visit and third trimester 1

2. Asymptomatic infection is common:

   • Many infected individuals show no symptoms 7
   • Up to 24% of asymptomatic females and 21.4% of asymptomatic males may be infected 6

3. Serious complications can develop if left untreated:

   • In women: PID, infertility, ectopic pregnancy, chronic pelvic pain 3
   • In men: epididymitis, urethritis, and rarely, urethral strictures 3

Pitfalls to Avoid

• Don't rely on symptoms for diagnosis as many infections are asymptomatic
• Don't overlook the need for partner treatment as reinfection is common
• Don't assume low risk in individuals with only one current partner, as past partners and partner's behavior also matter
• Don't forget to screen high-risk individuals according to guidelines, even without symptoms

By identifying individuals with these risk factors and implementing appropriate screening, the serious complications of chlamydia infection can be prevented through early detection and treatment.