Why do a rapid Strep test or throat culture?
A throat culture or rapid Strep test is the only way to know whether a sore throat is caused by Strep bacteria or a virus. Without treatment, a strep throat has a small risk for acute rheumatic fever. Rheumatic fever is a complication of strep infections that can lead to permanent damage to the valves of the heart. The Strep test is not urgent, however, since treating a strep infection within 7 days of when it begins can prevent rheumatic fever. A Strep test is not necessary if your child’s sore throat is part of a cold AND the main symptom is croup, hoarseness, or a cough, unless the sore throat lasts more than 5 days. Rapid strep tests are helpful only when their results are positive. If they are negative, a throat culture is usually performed to pick up the 10% of strep infections that the rapid tests miss. Avoid rapid strep tests performed in shopping malls or at home because they tend to be inaccurate.
