FDA approves easier tests for America's most common STIs

New, easier tests for two of the most common STIs have been cleared by the US FDA, paving the way for more rapid – and less uncomfortable – diagnosis and treatment. While tests for chlamydia and gonorrhea are already in widespread use, currently they can require relatively intrusive methods of sampling.

That's a problem, because both diseases can have serious implications if left untreated. Although each can be symptom free for some time, long-term affects can include sterility and other complications.

Until now, the only tests approved by the US Food and Drug Administration for both STIs were cleared for urine, vaginal, or endocervical samples. Now, the FDA says, it has granted clearance to Aptima Combo 2 Assay and the Xpert CT/NG devices for throat and rectum testing. It means that something as simple as a swab taken via the mouth could lead to a successful diagnosis.

"The availability of these two tests will fill an unmet public health need, by allowing for more screening," Tim Stenzel, M.D., Ph.D., director of the Office of In Vitro Diagnostics and Radiological Health in the FDA's Center for Devices and Radiological Health, said of the new approvals.

It's important, because rates of both chlamydia and gonorrhea in the US are on the rise. There are an estimated 1.7m cases of the former in the US, and more than half of million of the latter. The challenge is that even infected people can observe no symptoms, and thus unwittingly pass the STI on to someone else before it is diagnosed. That, combined with the fact that existing testing could be uncomfortable, had left healthcare professionals with an uphill struggle.

A sizable percentage of new STI cases in the US are among younger people. According to the ASHA, of the approximately 20 million new cases each year, around half of which are observed in youth aged 15-24. Chlamydia is the most common bacterial STI in the US, in part because most women and around half of men with it do not see any symptoms. Given undiagnosed STIs cause 24,000 women to become infertile each year, the ASHA recommends annual testing to every woman under 25.

The FDA granted its clearance via the premarket notification pathway, otherwise known as 510(k). Less arduous than the full FDA approvals process, it relies on demonstrating that a new device is "at least as safe and effective" – or "substantially equivalent" – to a current, legally marketed device. The FDA compared the two tests and their new methodology with samples of existing testing, and found they were both safe and effective.

It's unclear how soon the Aptima Combo 2 Assay and Xpert CT/NG will begin showing up in healthcare facilities as another option alongside the existing testing methods.