Sexual Health and STI Lecture Notes (Comprehensive)

1. Biology and Sexual Anatomy

  • Chromosomal Sex vs. Gonadal Sex vs. Phenotypic Sex

    • Chromosomal sex: Determined at conception (XXXX for female, XYXY for male). Variations like KlinefelterKlinefelter Syndrome (XXYXXY) or Turner Syndrome (XOXO) exist.

    • Gonadal sex: Development of ovaries or testes, influenced by the SRY gene on the Y chromosome.

    • Phenotypic sex: Development of internal and external reproductive organs, secondary sexual characteristics, and gender identity.

  • Hormonal Influences

    • Estrogens (e.g., estradiol): Primarily feminizing hormones, involved in menstrual cycle, bone density, and secondary sexual characteristics.

    • Androgens (e.g., testosterone): Primarily masculinizing hormones, involved in muscle mass, bone density, libido, and secondary sexual characteristics.

    • Hormone pathways and feedback loops (Hypothalamic−Pituitary−GonadalHypothalamic-Pituitary-Gonadal (HPG) axis).

  • Neurobiology of Sexual Response

    • Phases: Desire, Arousal (excitation), Orgasm, Resolution.

    • Involvement of neurotransmitters (e.g., dopamine, serotonin, norepinephrine) and hormones (testosterone, estrogen, oxytocin).

2. Gender Health: Identity, Expression, and Inclusive Care

  • Key Terminology

    • Sex assigned at birth: Classification as male, female, or intersex based on biological markers at birth.

    • Gender identity: An individual's internal sense of being male, female, both, neither, or somewhere else along the gender spectrum. It may or may not align with sex assigned at birth.

    • Gender expression: External manifestation of gender, expressed through names, pronouns, clothing, hairstyles, behavior, voice, and body characteristics.

    • Cisgender: Describes people whose gender identity aligns with their sex assigned at birth.

    • Transgender: Describes people whose gender identity differs from their sex assigned at birth.

    • Non-binary: An umbrella term for gender identities that are not exclusively male or female.

    • Gender dysphoria: Clinical term for discomfort or distress caused by a discrepancy between a person's gender identity and their sex assigned at birth.

  • Healthcare for Transgender and Gender Diverse Individuals

    • Hormone Replacement Therapy (HRT): Medications to affirm gender identity.

      • Feminizing HRT: Estrogens, anti-androgens (e.g., spironolactone). Effects include breast development, skin softening, redistribution of fat, decreased libido, reduced facial and body hair.

      • Masculinizing HRT: Testosterone. Effects include voice deepening, facial/body hair growth, clitoral enlargement, cessation of menses, muscle mass increase.

    • Gender Affirming Surgeries: Procedures to align physical appearance with gender identity (e.g., mastectomy, augmentation mammoplasty, vaginoplasty, phalloplasty).

    • Mental Health Support: Addressing dysphoria, anxiety, depression, and social support needs.

3. Inclusive Practice and Sexual Health Education

  • Patient-Centered Communication

    • Using chosen names and pronouns: Always ask and respect an individual's preferred name and pronouns.

    • Open-ended questions: Encourage patients to share their experiences and concerns.

    • Active listening and empathy: Validate patient experiences.

  • Creating an Inclusive Environment

    • Gender-neutral signage and forms.

    • Staff training on LGBTQ+ cultural competency.

    • Ensuring privacy and confidentiality.

  • Comprehensive Sexual Health Education

    • Consent: Emphasize explicit, enthusiastic, ongoing, and reversible consent.

    • Safer Sex Practices: Condoms (internal and external), dental dams, PrEP (Pre-Exposure Prophylaxis), PEP (Post-Exposure Prophylaxis).

    • Contraception: Methods include hormonal (pills, patch, ring, injection, implant, IUD), barrier (condoms, diaphragm, cervical cap), and permanent (vasectomy, tubal ligation).

  • Addressing Stigma and Discrimination

    • Impact on healthcare access and outcomes.

    • Advocacy for equitable healthcare policies.

4. Sexual Health and Sexually Transmitted Infections (STIs)

  • General Principles of STI Management

    • Screening: Routine screening for high-risk individuals (e.g., annual chlamydia/gonorrhea for sexually active women <2525).

    • Partner Notification: Informing and treating sexual partners to prevent re-infection and further spread.

    • Prevention: Condoms, PrEP, vaccination (HPV).

4.1. Common Bacterial STIs

  • Chlamydia trachomatis

    • Incubation Period: $7-21$ days, but often asymptomatic.

    • Transmission: Vaginal, anal, oral sex; mother-to-child during birth.

    • Symptoms:

      • Females: Cervicitis, urethritis (vaginal discharge, painful urination, abdominal pain, irregular bleeding).

      • Males: Urethritis (penile discharge, painful urination, testicular pain).

      • Rectal: Rectal pain, discharge, bleeding.

      • Pharyngeal: Usually asymptomatic.

    • Diagnosis: Nucleic Acid Amplification Test (NAAT) from urine, vaginal swab, or rectal/pharyngeal swab.

    • Treatment: Azithromycin (1g1g oral single dose) or Doxycycline (100mg100mg oral BID for 77 days).

    • Complications: Pelvic Inflammatory Disease (PID), infertility, ectopic pregnancy, epididymitis, Reiter's syndrome.

  • Neisseria gonorrhoeae

    • Incubation Period: $1-14$ days, but can be asymptomatic.

    • Transmission: Vaginal, anal, oral sex; mother-to-child during birth.

    • Symptoms: Similar to chlamydia but often more acute and purulent.

      • Females: Cervicitis, urethritis, vaginal discharge, painful urination.

      • Males: Urethritis (purulent penile discharge, painful urination).

      • Rectal/Pharyngeal: Can be asymptomatic; discharge or soreness.

    • Diagnosis: NAAT from urine, vaginal swab, or rectal/pharyngeal swab; culture for antimicrobial resistance testing.

    • Treatment: Dual therapy with Ceftriaxone (500mg500mg IM single dose) plus Azithromycin (1g1g oral single dose) or Doxycycline (100mg100mg oral BID for 77 days) due to increasing resistance.

    • Complications: PID, infertility, epididymitis, disseminated gonococcal infection (arthritis, dermatitis, endocarditis), neonatal conjunctivitis.

  • Syphilis (Treponema pallidum)

    • Incubation Period: Primary: $10-90$ days (avg. 2121 days).

    • Transmission: Direct contact with a syphilitic sore (chancre) during vaginal, anal, oral sex; mother-to-child (congenital syphilis).

    • Stages and Symptoms:

      1. Primary: Painless chancre at site of infection; resolves spontaneously in 3−63-6 weeks.

      2. Secondary: Rash (often on palms and soles), fever, lymphadenopathy, condyloma lata; appears weeks to months after chancre; resolves spontaneously.

      3. Latent: Asymptomatic, but serological evidence of infection; early latent (<11 year) and late latent (>11 year).

      4. Tertiary: Gummas (soft, tumor-like growths), cardiovascular syphilis (aortitis), neurosyphilis (dementia, paralysis).

    • Diagnosis:

      • Screening: Nontreponemal tests (RPR, VDRL) for active disease.

      • Confirmatory: Treponemal tests (TP-PA, FTA-ABS, EIA) remain positive for life.

    • Treatment: Penicillin G (benzathine intramuscular injection) is the drug of choice. Dosage varies by stage (

      • Primary/Secondary/Early Latent: Benzathine Penicillin G 2.42.4 million units IM single dose.

      • Late Latent/Tertiary: Benzathine Penicillin G 2.42.4 million units IM weekly for 33 doses.

      • Neurosyphilis: Aqueous Crystalline Penicillin G (18−2418-24 million units/day IV for 10−1410-14 days).

    • Complications: Neurosyphilis, congenital syphilis, increased risk of HIV acquisition/transmission.

4.2. Common Viral STIs

  • Herpes Simplex Virus (HSV-1 and HSV-2)

    • Incubation Period: $2-12$ days (avg. 3−73-7 days).

    • Transmission: Direct contact with lesions, mucosal surfaces, or genital/oral secretions, even when asymptomatic.

    • Symptoms: Painful vesicles that ulcerate, flu-like symptoms during primary outbreak. Recurrences are typically milder.

    • Diagnosis: Viral culture or PCR of lesion fluid; type-specific serologic tests for asymptomatic shedding or atypical symptoms.

    • Treatment: Antiviral medications (Acyclovir, Valacyclovir, Famciclovir) to manage outbreaks and suppress recurrences. No cure.

    • Complications: Neonatal herpes, psychosocial distress.

  • Human Papillomavirus (HPV)

    • Incubation Period: $1$ month to several years.

    • Transmission: Skin-to-skin contact, usually during sexual activity.

    • Symptoms:

      • Low-risk HPV types (6,116, 11): Genital warts (condylomata acuminata).

      • High-risk HPV types (16,18,31,33,4516, 18, 31, 33, 45): Precancerous lesions and cancers of the cervix, anus, vulva, vagina, penis, and oropharynx.

    • Diagnosis: Visual inspection for warts; Pap test for cervical screening; HPV DNA test (co-testing with Pap for women >3030).

    • Treatment: Removal of warts (cryotherapy, excision, topical agents); management of precancerous lesions; no cure for the virus itself.

    • Prevention: HPV vaccination (Gardasil 99) recommended for adolescents (11−1211-12 years) and young adults up to age 2626. Catch-up vaccination up to age 4545 may be considered.

  • Human Immunodeficiency Virus (HIV)

    • Incubation Period: Acute retroviral syndrome: $2-4$ weeks post-exposure. Progression to AIDS can take years.

    • Transmission: Unprotected sexual contact (vaginal, anal), sharing needles, mother-to-child (pregnancy, birth, breastfeeding), blood transfusions (rare in developed countries).

    • Symptoms:

      • Acute HIV: Flu-like symptoms (fever, rash, lymphadenopathy, sore throat).

      • Chronic HIV: Often asymptomatic; progressive immune system damage.

      • AIDS (Acquired Immunodeficiency Syndrome): Opportunistic infections, certain cancers (e.g., Kaposi's sarcoma), wasting syndrome.

    • Diagnosis: HIV antibody/antigen tests (4th4^{th}-generation assays), HIV RNA (viral load) test.

    • Treatment: Antiretroviral Therapy (ART) – typically a combination of 33 drugs from different classes. Reduces viral load to undetectable levels, restores immune function, and prevents transmission.
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