Rapid Screening for Syphillis

An electron microscopy image of two Treponema pallidum bacteria. T. pallidum is the bacterium that causes syphilis.. Photo courtesy of CDC/Joyce Ayers (1969)

Introduction - The Shape of the Syphilis Epidemic

For a while, in the latter half of the 20th century, it looked like syphilis might be on its way to eradication. Antibiotics had been proven to be an effective treatment and testing was both available and widespread. Disease surveillance showed that the number of infection were consistently decreasing, including the number congenital syphilis cases affecting infants -- cases that were often fatal.

It seemed like a success story, particularly for White people. Syphilis remained far more common in minority communities, but the statistics showed it was declining even there.

Then all of a sudden, at the dawn of the 21st century, syphilis cases were on the rise again - primarily among men who have sex with men. Research suggested that much the sudden increase was due to the fact that oral sex was considered a safer way to have sex during the early days of the HIV epidemic. It was, for HIV. However, oral sex turned out to be an excellent way to transmit syphilis.

With syphilis on the rise again, however, some of the downsides of the VDRL test started to become clear. Specifically, as it is not a rapid test, it was far too easy to lose track of patients in the time between when they came in for testing and when results became available. Keeping in touch with patients can particularly difficult for poor, young, and minority patients, some subset of whom may be at particular risk of syphilis infection.

Rapid Syphilis Testing - Now an Option

Fortunately, there is now a faster option for syphilis testing. Although the Syphilis Health Check, a rapid test for syphilis, was approved back in 2011, it was not widely available due to restrictions on where it could be used. Right before Christmas 2014, however, the FDA granted a waiver to the Syphilis Health Check test.

The waiver should allow it the rapid test be made available in a broad range of community health centers, doctors offices, and other medical settings.

That's a good thing, because it's a very straightforward test -- one which can even be performed correctly by untrained testers. The Syphilis Health Check is performed on a small sample of blood taken by finger-stick. Results of the test are available in less than 15 minutes, which means that treatment can begin at the same office visit where testing is performed. Although positive results should be confirmed with a more accurate test to be certain of the diagnosis, that does not prevent doctors from prescribing antibiotics right away if they feel that doing so is wise.

Rapid Testing - Are There Downsides?

There is a growing movement towards offering rapid testing and home testing for diseases such as syphilis and HIV, which are known to affect high-risk, hard to reach, communities. Until recently, the worry had been that such tests are often neither as sensitive or specific as in-office lab tests, which means that they come with a higher risk of inaccurate test results.

That's a potentially serious problem with such stigmatized diseases.  However, the benefits of rapid tests and home tests are also profound. Doctors don't lose track of patients between testing and diagnosis. They don't have to worry about whether patients will still be at the same phone number or have time to come back in for another appointment. They don't have to risk patients deciding that they'd rather not know their lab results than deal with them. For diseases like syphilis, where the consequences of undetected infections can be severe and treatment is relatively benign, a little uncertainty about lab results is a more than worthwhile tradeoff.


Centers for Disease Control and Prevention. (2014) Sexually Transmitted Disease Surveillance 2013. Atlanta: U.S. Department of Health and Human Services

Food and Drug Administration. (2014, December 15) FDA grants CLIA waiver expanding the availability of rapid screening test for syphilis. Retrieved from http://www.fda.gov/newsevents/newsroom/pressannouncements/ucm426843.htm on 1/14/15

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