Group A Streptococci are organisms that typically c ause illnesses such as tonsillitis, pharyngitis and scarlet fever. These infections can lead to serious complications, including rheumatic fever and acute glomerulonephritis.1 Rapid diagnosis and appropriate antibiotic therapy of Group A Streptococcal infections appear to be the best means of preventing these complications. The traditional means of detecting Group A Streptococcal infection involves 24-48 hour culture of throat swab specimens or other exudates, confirming beta-hemolysis, and showing susceptibility to bacitracin. Group A, but generally not other groups of beta-hemolytic Streptococci, is bacitracin susceptible which provides a presumptive diagnosis of Group A Streptococcal disease.

Positive for Group A Streptococcus Respiratory infections, including pharyngitis, can be caused by Streptococcus from serogroups other than group A as well as other pathogens. The test will not differentiate asymptomatic carriers of Group A Streptococcus from those exhibiting Streptococcal infection. In rare cases, test specimens heavily colonized with Staphylococcus aureus(>1010) can yield false positive results. Test results must always be evaluated with other data available to the physician. A negative test result might occur if the level of extracted antigen in a sample is below the sensitivity of the test. Additional follow-up testing using the culture method is recommended if the test result is negative.