Rapid syphilis test released in U.S.

A new point-of-care test for syphilis will provide clinicians another tool in battling increases in the sexually transmitted infection (STI). The new test, Syphilis Health Check (Diagnostics Direct, Stone Harbor, NJ), will no longer require lengthy wait times for results, refrigeration, or the drawing of blood to test for the STI.

Primary and secondary syphilis cases reported to the Centers for Disease Control and Prevention (CDC) rose from 13,500 in 2008 to 13,997 in 2009, for an increase of 3.7%. The rate of primary & secondary syphilis in the United States in 2009 was 4.5% higher than the rate in 2008 (4.6 cases per 100,000 population versus 4.4 cases.) After persistent declines during 1992-2003, the rate among women increased from 0.8 cases in 2004 to 1.4 cases in 2009.1

Syphilis remains a major health problem in the South and in urban areas in other regions of the country, according to the CDC.1 Increases in cases among men having sex with men (MSM), including those men who partner with men and women, have been reported; they are characterized by high rates of HIV co-infection and high-risk sexual behavior.2-6 A review of case reports from 44 states and the District of Columbia show 62% of primary and secondary syphilis cases are among MSM.1

Clinicians in public health who are involved in STD control work have been clamoring for a point-of-care test for syphilis, says Peter Leone, MD, professor of medicine at the School of Medicine at University of North Carolina at Chapel Hill

While the test does not serve as a definitive confirmation of disease, it gives clinicians the possibility to test outside the clinical laboratory and to immediately identify individuals who will need further evaluation and treatment, he notes.

While there are limitations, as there are to any test, the Syphilis Health Check offers an ideal way to scale up testing in situations in which clinicians might not be drawing blood, such as HIV testing events, says William Smith, executive director of the Washington, DC-based National Coalition of STD Directors.

Take a closer look

The Syphilis Health Check is a qualitative rapid membrane immunochromatographic assay for the detection of Treponema pallidum (TP, syphilis) antibodies in human whole blood, serum, or plasma. It can be used as an initial screening test or with a non-treponemal laboratory test and clinical findings to aid in the diagnosis of syphilis infection.

The test uses a unique combination of anti-human immunoglobulins gold conjugate and highly purified TP recombinant proteins to specifically detect anti-TP antibodies. To perform the test, the test device is removed from its wrapper and labeled with the patient's name or control number. Using a lancet to stick the patient's finger, a pipette is used to draw a few drops of blood. Just two drops of blood are added to the sample well of the test device, followed by four drops of buffer. Test results may be read in 10 minutes. If the test is negative, there is one colored band in the control area, while if positive, colored bands are shown in the control and test areas. (For more information on the test, see the resource at the end of this article.) The test price should average about $10-$15 per test, says Joseph Vacante, Trinity Biotech general manager — North America.

Another syphilis test is undergoing clinical trials in the United States. Chembio Diagnostics in Medford, NY, has received a CE marking for its DPP Syphilis Screen & Confirm Assay. The marking indicates the product has met all relevant safety requirements to allow it to be sold in countries with the European Economic Area.

According to the company, the test permits dual non-treponemal and treponemal testing, which eliminates the need and resulting cost of separate laboratory tests. The company says it anticipates filing an application for Food and Drug Administration approval in 2012.

References

  1. Centers for Disease Control and Prevention. 2009 Sexually Transmitted Diseases Surveillance. Accessed at http://www.cdc.gov/std/stats09/default.htm.
  2. Centers for Disease Control and Prevention. Resurgent bacterial sexually transmitted disease among men who have sex with men — King County, Washington, 1997-1999. MMWR 1999; 48:773-777.
  3. Centers for Disease Control and Prevention. Outbreak of syphilis among men who have sex with men — Southern California, 2000. MMWR 2001; 50:117-120.
  4. Centers for Disease Control and Prevention. Primary and secondary syphilis among men who have sex with men — New York City, 2001. MMWR 2002; 51:853-856.
  5. Chen SY, Gibson S, Katz MH, et al. Continuing increases in sexual risk behavior and sexually transmitted diseases among men who have sex with men: San Francisco, California, 1999–2001. Am J Public Health 2002; 92:1,387-1,388.
  6. D'Souza G, Lee JH, Paffel JM. Outbreak of syphilis among men who have sex with men in Houston, Texas. Sex Transm Dis 2003; 30:872-873.

Resource

For more information on the Syphilis Health Check test, contact: