Sexually Transmitted Diseases Overview

Sexually Transmitted Diseases (STDs)

• STDs are diseases spread through sexual contact.
• Classification is based on the causative microorganism.

Bacterial STDs

• N. Gonorrhoea: Causes gonorrhea.
• Treponema Pallidum: Causes syphilis.
• Chlamydia Trachomatis: Causes chlamydia.
• Haemophilus Ducreyi: Causes chancroid.
• Genital Mycoplasma: A type of genital bacteria.

Viral STDs

• Herpes Simplex Virus (HSV): Causes herpes.
• Human Papilloma Virus (HPV): Causes genital warts.
• AIDS Virus (HIV): Causes AIDS.
• Cytomegalovirus (CMV): Causes CMV.
• Hepatitis B Virus: Causes hepatitis B.
• Mullascum Contagiosum: Causes the skin condition.

Fungal STDs

• Candidiasis: Causes a yeast infection.

Protozoal STDs

• Trichomonas vaginalis: Causes trichomoniasis.
• Giardia lamblia: Causes giardiasis.

Parasitic STDs

• Scabies: A skin condition.
• Pediculosis: Lice infestation.

Gonorrhea

• Causative organism: Gram-negative intracellular diplococci (Neisseria gonorrhoeae).
• Incubation period: 2 to 8 days.
• Affects areas with thin epithelium (not stratified).
• Can cause urethritis, bartholinitis, cervicitis, salpingitis.
• Symptoms: Asymptomatic (carrier), purulent vaginal discharge, dysuria, frequency.
• Signs: Urethritis, skenitis, salpingitis, signs of PID.
• Treatment: Cefotaxime + Doxycycline, Ciprofloxacin + Doxycycline, Azithromycin, etc. Treatment should include sexual partners.

Chlamydial Infections

• Causative organism: Chlamydia trachomatis, an obligate intracellular bacterium.
• Several serotypes; some cause LGV; others lead to genital infections (D-K).
• C. trachomatis is a common STD among sexually active women.
• Sites of Affection: Cervicitis, urethritis, salpingitis, pelvic inflammatory disease (PID). Not a common cause of vaginitis, but a common cause of vaginal discharge.
• Symptoms: Yellowish mucopurulent vaginal discharge, dysuria, frequency.
• Diagnosis: Microscopic examination of saline smears (white blood cells without clue cells, yeast, or trichomonas), tissue culture, detection of chlamydial antigens by monoclonal antibodies or ELISA.
• Treatment: Doxycycline, Erythromycin, Azithromycin. Include sexual partners in treatment.

Syphilis

• Causative organism: Treponema pallidum (spirochete).
• Congenital or acquired (STD).
• Incubation period: 2 to 6 weeks.
• Clinical phases:
  • Primary: Painless ulcer (chancre) with a hard base, on genitals or extragenitals (mouth, anus), with lymph node enlargement.
  • Secondary: Systemic manifestations, rash (red macules and papules on palms and soles), Condylomata lata (raised gray lesions), lymphadenopathy.
  • Tertiary: Cardiovascular or neurological manifestations, gummas (necrotic lesions) on skin and bones.
• Diagnosis: Dark-field microscopy (discharge), serological tests (VDRL, RPR, FTA-ABS, Treponema pallidum immobilization test).
• Treatment: Penicillin is the drug of choice, different regimens for different stages. For penicillin allergy, alternative regimens such as Doxycycline exist (depending on stage). For pregnant women, Erythromycin. For women with more than a year history, lumbar puncture is essential to rule out neurosyphilis.

Lymphogranuloma Venereum (LGV)

• Chronic infection of lymphatic tissues in the genital region (vulva, urethra, rectum, cervix).
• Common in tropical areas.
• Causative organism: Chlamydia trachomatis.
• Incubation period: 3-4 days.
• Clinical picture:
  • Primary: Shallow painless ulcers.
  • Secondary: Painful inguinal and perirectal lymphadenopathy, buboes (swollen lymph nodes).
  • Tertiary: Rupture of buboes leading to sinus and fistula formation.
• Diagnosis: Polymerase chain reaction (PCR) for C. trachomatis.
• Treatment: Oral Tetracycline or Erythromycin for 2-3 weeks, aspiration of buboes.

Genital Warts

• Causative organism: Human papillomavirus (HPV).
• Highly contagious DNA virus
• Types 16 & 18: Flat warts, risk of cervical intraepithelial neoplasia (CIN)
• Types 6 & 11: Exophytic warts (no malignant potential).
• Vulva, vagina, perineum, anus, cervix are common sites.
• Diagnosis: Pap smear (Koilocytes, perinuclear halos), colposcopy.
• Treatment:
  • Small warts: Topical application of podophyllic, trichloroacetic acid, 5-fluorouracil.
  • Large warts: Cryotherapy, electrocautery, laser therapy.

Genital Herpes Simplex Virus (HSV)

• Caused by DNA virus (highly contagious).
• HSV-2 more common than HSV-1 for genital herpes.
• Initial infection: Skin → lumbosacral dorsal root ganglia → persistent but subclinical infection.
• Recurrent infections: Activation of virus in ganglia → peripheral nerves → skin lesions.
• HSV-1 causes oral herpes (fever blisters).
• Incubation: 2-7 days.
• Primary infection symptoms: 10-day duration, general symptoms (malaise, fever), multiple vesicles coalesce into superficial ulcers (vagina, cervix).
• Associated pain, tenderness, inguinal lymphadenopathy.
• Subclinical infections in 50%
• Diagnosis: Cytologic smear (multinucleated giant cells), viral culture.
• Treatment:
  • General: Keeping lesions dry, analgesics.
  • Specific: Antiviral (acyclovir) - oral or topical (shortens duration, reduces viral shedding).
  • Follow-up with Pap smears.

Acquired Immunodeficiency Syndrome (AIDS)

• Caused by Human Immunodeficiency Virus (HIV).
• HIV attacks CD4+ T lymphocytes, lowering immune response.
• Opportunistic infections occur when CD4+ cell count falls below 200.
• CD4 is a specific antigen on T lymphocytes.
• HIV infection weakens ability of host to fight invading organisms.
• Clinical picture: Asymptomatic carrier state years, persistent lymphadenopathy, thrombocytopenia, AIDS-related complex (oral candidiasis, pneumonias, viral infections [HSV, CMV], tuberculosis [TB], toxoplasmosis).
• Diagnosis: History (STD, homosexuality, blood transfusion, drug use), persistent lymphadenopathy, fungal, bacterial, or viral infections, ELISA (high rates of false positives), Western Blot, Viral Culture.
• Treatment: Primarily prophylactic to prevent infection: health education, safe sexual practices, testing before blood transfusions, addiction treatment.

This quiz covers a comprehensive overview of sexually transmitted diseases (STDs), including their classifications based on the causative microorganisms: bacterial, viral, fungal, protozoal, and parasitic STDs. It's essential for understanding the different types of infections, their causes, and implications for health.