Quick Exam Recall Points

Cholera

• Rice-water diarrhoea - no fever initially; massive fluid loss (10-20 L/day)
• Exotoxin acts via adenylate cyclase-cyclic AMP system
• Dark field microscopy - "shooting stars" appearance
• IV fluid of choice = Ringer's Lactate; oral = low-osmolarity ORS (245 mOsm/L)
• Antibiotic = Doxycycline (single 300 mg dose for adults)
• Bleaching powder 6 mg/L kills vibrios instantly
• Carriers detected by purged stool (Magnesium sulphate)

Diarrhoea Management

• Plan A (no dehydration): Extra fluids at home + zinc + continue feeding
• Plan B (some dehydration): 75 mL/kg ORS over 4 hours
• Plan C (severe dehydration): IV Ringer's Lactate 100 mL/kg
• Zinc: 20 mg/day x 14 days (reduces duration by 25%, recurrence in next 3 months by 25%)
• Anti-diarrhoeals (loperamide etc.) are CONTRAINDICATED

Typhoid

• Only reservoir = Man; chronic carriers excrete for >1 year (gall bladder)
• "Typhoid Mary" - >1300 cases in her lifetime
• Widal: O antibodies day 6-8, H antibodies day 10-12; moderate sensitivity only
• Gold standard lab = Bone marrow culture (>90% yield)
• Treatment = Fluoroquinolones (Ciprofloxacin); MDR - use Ceftriaxone or Azithromycin
• Isolate until 3 negative stool + urine cultures
• Vi-polysaccharide vaccine: single dose, ≥2 years, revaccinate every 3 years
• Ty21a oral: 3 doses (Day 1, 3, 5), ≥5 years, revaccinate every 3 years
• TCV (Typbar-TCV): works in children <2 years, included in India's immunization schedule