infectious diseases
Shigellosis
Key Points
Shigellaspecies are a highly contagious cause of dysentery; humans are the only reservoir. Watery diarrhea may be accompanied by abdominal pain and marked urgency to defecate; stools may contain mucus, pus, and often blood. S. dysenteriaetype 1 (not common in the US, except in returning travelers) produces Shiga toxin, which may cause hemolytic-uremic syndrome. Significant dehydration and electrolyte loss with circulatory collapse and death occur mainly in debilitated adults and children<2 years. Supportive care is usually adequate, but give antibiotics (a fluoroquinolone,azithromycin,ceftriaxone) to young children and to older, debilitated, or severely ill patients; resistance toampicillin,trimethoprim/sulfamethoxazole (TMP/SMX), and tetracyclines is common. 