Shigellosis laboratory findings

The majority of patients with shigellosis have no significant derangements in either blood or stool work-up. Common findings include leukocytosis with left shift on blood examination, and blood and/or mucus in stools on stool examination. Multiple blood and stool cultures are needed to rule out bacteremia and to obtain antibiotic susceptibility testing, but the majority of cases yield negative cultures. Hematology, renal, and liver function testing may be required in some cases to rule out the development of any complications associated with shigellosis, such as severe dehydration, cholestatic liver disease, or hemolytic uremic syndrome (HUS).

• Leukocytosis with left shift is common, but leukopenia has also been reported.
• Anemia
• Thrombocytopenia

• Hyponatremia

• Hypoglycemia

• Elevated C-reactive protein (CRP)
• Elevated erythrocyte sedimentation rate (ESR)

• Azotemia (elevated blood urea nitrogen)
• Elevated concentration of serum creatinine

• Mild elevation in bilirubin

• Multiple blood cultures are usually withdrawn and may be positive for Shigella in cases complicated with bacteremia.

• Fecal blood
• Fecal leukocytes

• Microscopic evidence of leukocytes on stool smear with methylene-blue stain

• Multiple stool cultures are needed and may be positive for Shigella in the minority of cases, especially early during the disease.
• Stool samples typically cultured using agars such as: MacConkey agar, Hektoen enteric agar, Salmonella-Shigella agar, eosin-methylene blue agar, or xylose-lysine-deoxycholate agar. Stool cultures typically demonstrate colorless colonies that do not ferment lactose.

• 
  Gram-negative Shigella boydii bacteria grown on a medium of sheep’s blood agar (SBA) 24hrs. From Public Health Image Library (PHIL). ^[1]
• 
  Gram-negative Shigella boydii bacteria grown on a medium of sheep’s blood agar (SBA) 24hrs. From Public Health Image Library (PHIL). ^[1]

Template:WikiDoc Sources