Sexually Transmitted Infections (STIs) Presentation

Overview

• Terminology: Use "sexually transmitted infections" (STIs) as per WHO.
• Exam questions derived from listed objectives.

Trends and Statistics

• Data Collection: CDC collects data yearly on chlamydia, gonorrhea, and syphilis.
• New Cases: 26 million new cases yearly; half in ages 15-24.
• Common STIs:
  • HPV: 42 million cases
  • HSV-2: 18.6 million cases
  • Chlamydia: ~2.5 million cases
  • Gonorrhea: Over 200,000 cases
• Cost: STIs cost the US healthcare system $16 billion per year.

Goals of Therapy

1. Treat or cure the infection.
   • Certain infections (e.g., genital herpes, HIV) cannot be cured but symptoms can be managed.
2. Prevent the spread of infection.
3. Prevent the recurrence of infection or symptoms.

Chlamydia

• Cause: Bacterial infection, frequently diagnosed.
• Treatment: Azithromycin (Zithromax) - effective in one dose.
  • Mechanism: Interferes with bacterial protein synthesis.
  • Side Effects: Nausea, vomiting.
• Complications if Untreated: Pelvic inflammatory disease, ectopic pregnancy, infertility.

Gonorrhea

• Cause: Bacterial infection.
• Treatment: Ceftriaxone (Rocephin) via intramuscular injection.
  • Mechanism: Prevents bacterial replication.
  • Side Effects: Muscle pain, tenderness.
  • Often treated alongside chlamydia (with azithromycin).
• Complications: Same as chlamydia (pelvic inflammatory disease, ectopic pregnancy, infertility).

Genital Herpes (HSV-2)

• Cause: Herpes simplex virus-2 (HSV-2).
• Treatment: Valacyclovir (Valtrex) - antiviral.
  • Mechanism: Stops viral reproduction.
  • Dosage: Twice daily for 7-10 days during outbreaks; daily between outbreaks.
  • Side Effects: Headaches, nausea, vomiting.
• Complications if Untreated: Transmission to fetus/newborn, systemic infection in immunocompromised patients.

Expedited Partner Therapy (EPT)

• Purpose: To treat partners of patients diagnosed with STIs.
• Method: Provide prescriptions for partners.
  • Medications: Azithromycin for chlamydia, cefixime (oral) for gonorrhea.
• Legality: Legal in MN and 45 other states.

Prevention of STIs

• Abstinence: Only guaranteed method.
• Monogamous Relationship: With an uninfected partner.
• Regular Checkups: Important if not in a monogamous relationship.
• Condoms: Reduce, but do not eliminate, risk.
• HPV Vaccine: Available for prevention.

HPV Vaccine

• Cause: Human papilloma virus (HPV) leads to genital warts, cervical cancer.
  • Symptoms: Often asymptomatic, hard to prevent spread.
• Vaccine: Gardasil (approved for ages 9-26).
  • Effectiveness: Almost 100% in preventing precancerous lesions and genital warts.
  • Series: Previously 3 doses, now 2 doses for those <15 years.
  • Current Version: Gardasil 9, covers 9 strains of HPV.