Chapter 20: Infections of the Reproductive System

The reproductive system maintains health through multiple protective mechanisms including normal microbial flora that competitively exclude pathogens, acidic vaginal pH that inhibits bacterial growth, continuous flushing by urine flow, and antimicrobial enzymes such as lysozyme present in cervical secretions and semen. A fundamental distinction exists between male and female reproductive microbiology: the male urethra remains largely sterile except at its distal end, while the female reproductive tract maintains a dynamic microbial community that fluctuates with hormonal changes induced by contraceptive use, pregnancy, and menopause. Infections originate through two primary mechanisms—endogenous infections result from overgrowth of commensal organisms when normal defenses are compromised, while iatrogenic infections are introduced through medical interventions such as intrauterine device placement or unsanitary delivery practices. Bacterial vaginosis represents a polymicrobial endogenous infection where organisms like Gardnerella vaginalis proliferate following elevation of vaginal pH and disruption of lactobacillus dominance. Toxic shock syndrome constitutes a life-threatening systemic complication when Staphylococcus aureus colonizes superabsorbent tampons and releases exotoxin C into circulation. Group B Streptococcus infection demands prenatal screening and intravenous antibiotic prophylaxis during labor to prevent neonatal sepsis and meningitis. Pelvic inflammatory disease encompasses upper reproductive tract infection with potential sequelae of infertility and ectopic pregnancy, while endometritis involves uterine lining infection typically following tissue trauma. Candidiasis results from opportunistic proliferation of Candida albicans when bacterial competition decreases, particularly following antibiotic therapy. In males, prostatitis—inflammation of the prostate caused primarily by enteric organisms including Escherichia coli—represents the most common non-sexually transmitted infection, alongside epididymitis and balanitis. Diagnosis of reproductive tract infections relies predominantly on microscopic analysis of vaginal or urinary discharge.