Clinical and Epidemiologic Features of Bacterial STIs and HIV Transmission

Water and Hygiene

• Even bottled water can be unsafe in some countries
• Ways to treat water: heat, coagulation-flocculation, filtration, halogens, chlorine dioxide, ultraviolets
• Water bottle challenge: turn the bottle over and squeeze; if water or cap comes out, probably resealed

Infections and Diseases

• Top 5 causes of death in international travelers: malaria is the greatest cause of infectious deaths
• Snakebites: presentation varies per species, treatment includes supportive care, species-specific antivenin, and tetanus and bacterial prophylaxis
• Spider bites: causes necrosis, muscle spasms, renal failure, liver failure, hemolysis; treatment is supportive
• Scorpion stings: causes hyper-neuromuscular-autonomic functions, cytokine storm; treatment is supportive, antivenom available for Leiurus and Centruroides

Sexually Transmitted Infections (STIs)

• High-Altitude Conditions (>2,500m): describe key clinical and epidemiologic features of major bacterial STIs
• HIV transmission: having STIs increases risk of acquiring HIV by 2-3 fold
• Taking a sexual health history: ask specific questions, such as when the last time was for sexual activity, testing, and partner information

Syphilis

• Rates have been increasing since the 1990s, with a higher prevalence in males, especially middle-aged males
• Primary Syphilis: painless ulcer at site of inoculation, can resolve on its own, and may contribute to genetic ulcer disease
• Secondary Syphilis: bacteria spreads all over the body
• Congenital Syphilis: acquired from infected mother to baby, emphasizing the importance of pre-natal screening
• Neurosyphilis: can complicate any stage of syphilis, diagnosed via lumbar puncture and CSF VDRL or FTA-Abs positive

Diagnosis of Syphilis

• Screening test: Chemiluminescent Microparticle Immunoassay (CMIA) looks for antibodies
• Confirmatory tests: Rapid Plasma Reagin (RPR) confirms diagnosis and gives quantitative titre

Diarrhea

• Non-inflammatory: affects small bowel, presents as large volume, watery diarrhea, may include nausea, vomiting, and abdominal cramps
• Inflammatory: affects large bowel, presents as bloody, mucoid, small volume diarrhea, may be febrile/toxic
• Invasive: affects small bowel, presents as systemic symptoms common, may or may not be associated with diarrhea