<prompt> Antecedent diagnosis of Group A streptococcal infection in Acute rheumatic fever can be made by?AS0CRPESR elevationLow C3 levels  <response>: Ref: Nelson 20th edition, P 1333Because other illnesses may closely resemble Acute rheumatic fever, antecedent group A Streptococcal Infection is needed whenever possible. The tests are Increasing or rising Anti-Streptolysin O titer or other streptococcal antibodies indicates recent streptococcal infection A Positive throat Culture A Positive Rapid group streptococcal carbohydrate antigen test in a childGuidelines for the Diagnosis of Initial or Recurrent Attack of Rheumatic Fever Jones Criteria, Updated 20151Major manifestationsMinor manifestationsSupporting evidence of antecedent group a streptococcal infectionCarditisPolyarthritisErythemamarginatumSubcutaneous nodules ChoreaClinical features: Arthralgia Fever Laboratory features:Elevated acute phase reactants: Erythrocyte sedimentation rate C-reactive protein Prolonged P-R intervalPositive throat culture or rapid streptococcal antigen test.Elevated or increasing streptococcal antibody titer 