Rapid Antigen Test Results for Group A Streptococcus in Healthy Adults

The Unites States recommends the use of rapid antigen tests, but a number of other countries do not, citing a high prevalence of streptococcal carriers and only moderate sensitivity of rapid antigen tests [1]. Indeed, to fully understand when rapid antigen tests should be used, we need to know the streptococcal carrier rate for adults in the United States. Although there is a fair amount of data in this regard for children [2,3], the only study to report this value for adults was from over 20 years ago and was from Sweden [4]. That studied reported a Group A Streptococcus (GAS) carrier rate of 2.4-3.7% in healthy adults.

Given how many patients seek medical care for sore throats that may potentially be streptococcal pharyngitis, the investigators believe more data about the GAS carrier rate and the rate of false positive rapid antigen tests is necessary. Thus, the investigators propose a prospective study to evaluate the rate of positive rapid antigen tests in healthy adult patients in our community.

The investigators will perform rapid antigen tests for GAS on healthy adult subjects without any symptoms. Consenting patients will fill out a brief data collection form about their medical history, and an investigator will perform a rapid antigen throat swab to assess for GAS. The results of the rapid antigen test will be recorded, and a logistic regression analysis will be performed to determine if certain factors within the subject's medical history are predictive of positive rapid strep tests.