The diagnosis of RF through recovery of streptococci from positive throat cultures and the use of immunological assays such as Anti-Streptolysin O (ASO) would provide useful in the diagnosis of streptococcal infections. The study therefore is aimed at determining the ASO titre in comparism to positive blood culture in determining the prevalence of GAS in the study area. A total of hundred swab and blood samples were collected for Streptococcus pyogenes isolation and characterization using cultural and confirmed using the Streptococcus identification kit. Qualitative and semi quantitative ASO determination was done using the ASO latex agglutination kit. The overall prevalence for Streptococcus pyogenes was 16% as determined by blood culture. Of the 16 patients that tested positive to cultural tests, 11 (68.75%) tested positive for ASO while the remaining 5(31.25%) were negative. The level of ASO in patients that tested positive for the presence of ASO ranged from 400IU/ml to 3200IU/ml. C10 and C13 showed the highest concentration of 3200IU/ml respectively with a mean of 1018.19IU/ml. Positive culture methods remain the effective method for diagnosis of Streptococcal infection. However, ASO remains a cheaper and easier method for diagnosis and could provide baseline information for use in diagnosis in developing countries though it has not been deployed in many clinical settings.
Keywords: Anti-Streptolysin O (ASO), GAS, latex agglutination, streptococcal infections
