<prompt> Acalculous cholecystitis is caused by all exceptDMTPNLeptospirosisEstrogen therapy  <response>: Causes of Acalculous cholecystitis Common causes Elderly and critically ill patients after trauma Burns Longterm TPN Major operationsAbdominal aneurysm repair and cardiopulmonary bypass Diabetes mellitus Uncommon causes Vasculitis Obstructing GB adenocarcinoma GB torsion Parasitic infestation Unusual bacterial infection - Leptospira, streptococcus, salmonella , Vibrio cholera Ref: Harrisons 19th edition Pgno : 2081 