Describe the pathogens, transmission, incubation period, infectivity and prevention.
Pathogens: Shigella dysenteriae, Shigella flexneri, Shigella sonnei
Gram-negative rods
Produce Shiga toxin (enterotoxin) and endotoxin
Invade M cells via pinocytosis and travel from cell to cell via actin filaments (no hematogenous spread)
Transmission
Fecal-oral (especially a concern in areas with poor sanitation)
Oral-anal sexual contact
Foodborne (unpasteurized milk products and raw unwashed vegetables)
Contaminated water
Incubation period: 0–2 days
Infectivity: highly contagious; very low infective dose required (≥ 10 bacteria)
Prevention: no vaccine available
List clinical features.
Duration: 2–7 days
High fever
Tenesmus, abdominal cramps
Profuse inflammatory, mucoid-bloody diarrhea
Describe the treatment.
Supportive therapy for gastroenteritis: e.g., bland diet, oral rehydration therapy
Antibiotic therapy
Preferred regimens
Ciprofloxacin
OR azithromycin
OR ceftriaxone
Alternative: trimethoprim/sulfamethoxazole
List complications.
HUS
Intestinal complications (e.g., toxic megacolon, colonic perforation, intestinal obstruction, proctitis, rectal prolapse)
Febrile seizures
Reactive arthritis
Last changed2 years ago