Abstract Background Elevated serum concentrations of Anti- Streptolysin-O(ASO) can be used to provide serologic evidence past or present infection by β-Hemolytic Streptococci. Increasing ASO antibodies are produced in response exotoxins secreted the bacteria. Measurement antibody levels as an aid diagnosis diseases such glomerulonephritis, rheumatic fever, bacterial endocarditis, tonsillitis, a...