Gall stones in children is caused by all EXCEPT:

Leptospira interrogans infection REF: Nelson's pediatrics page 1566 Conditions Associated with Cholelithiasis: Chronic hemolytic disease (sickle cell anemia, spherocytosis) Obesity Ileal resection or disease Cystic fibrosis Chronic liver disease Crohn's disease Prolonged parenteral nutrition Prematurity with complicated medical or surgical course Prolonged fasting or rapid weight reduction Treatment of childhood cancer Abdominal surgery Pregnancy Acute Acalculous cholecystitis usually caused by: Infection-Pathogens include streptococci (groups A and B), gram-negative organisms paicularly Salmonella, and Leptospira interrogans. Parasitic infestation with Ascaris or Giardia lamblia may be found. Acalculous cholecystitis may rarely follow; abdominal trauma, burn injury Acalculous cholecystitis may be associated with a systemic vasculitis, such as polyaeritis nodosa.