Office rapid strep tests: State of the art
New device-based strep tests improve our ability to detect group A streptococcus early in the course of the infection, expediting diagnosis and treatment.
Waived “molecular testing” is now available
Alere (Waltham, Massachusetts) gained CLIA-waived status in April 2015 for its i Strep A test system. The i Strep A device detects GAS bacteria in throat swab specimens using Alere's proprietary isothermal nucleic acid amplification technology that produces results within 10 to 15 minutes. A color video displayed on the device’s screen walks users through the testing process. A sample receiver cartridge is placed in the machine and warmed for 3 minutes. The swab is placed in the cartridge for just 10 seconds, and then a pipette cartridge is used to transfer the sample onto a testing cartridge. The lid is closed and the testing cycle begins.
You can walk away at this point and return in 8 minutes to see the result on the device’s LCD screen. Results are stored in memory and can be printed via an attached printer. According to Alere, the overall sensitivity and specificity of the Alere i Strep A are 95.9% and 94.6%, respectively. Alere could not tell me the device’s “limit of detection,” but because it is a PCR-type test one would expect it to be low (see above). The test is a “molecular test” so it is billed under a unique CPT code— 87651—that yields higher reimbursement compared with nonmolecular strep tests that are billed under the code 87880QW. The cost of the Alere i Strep A device and tests have not been released as of this writing.