ID Board Review/Bacterial Diseases/Gram-negative Rods (GNR)/Enterobacteriaceae/Shigella

Histology

 * Gram-negative bacilli in Enterobacteriaceae
 * Nonmotile, nonencapsulated
 * Doesn't ferment lactulose and lacks urease activity

Pathophysiology

 * Low infectious inoculum
 * One of the most communicable forms of bacterial diarrhea w 80% of infections transmitted from person to person

Clinical Presentations

 * Often in young/pediatric patients
 * Asymptomatic to severe dysentery
 * Often watery diarrhea, but bloody diarrhea is often
 * Can progress to HUS

Endemic Areas/Environments

 * Daycares, often daycare attendance
 * International travel
 * STI among MSM
 * Concomitant HIV infection might modulate transmission