Lab Tests for Herpes Often Give Wrong Results

A recent survey of laboratories performing herpes simplex virus (HSV) testing found many used blood tests that often give false results.

In a proficiency examination of HSV testing, the College of American Pathologists sent 172 participating labs a blood sample containing HSV-1 antibodies but no HSV-2 antibodies. Though virtually all the labs detected the presence of HSV-1, more than half erroneously indicated the sample contained HSV-2 antibodies.

Only glycoprotein G-based tests have been proven effective in typing HSV antibodies, noted study authors Drs. Zane A. Brown and Rhoda Ashley Morrow. Of the 94 labs that reported what test they used, the 44 labs that used glycoprotein G-based tests all accurately reported no HSV-2 antibodies. The remaining labs, in contrast, "demonstrated high false-positive rates (14 percent to 88 percent) for HSV-2 antibodies."

Inaccurate HSV tests "will continue being marketed until the companies voluntarily withdraw them from the market," said Brown. "This places the burden on the health care provider ordering the test to know which lab uses what test, which is beyond the scope of training and capability of most health care providers." If HSV infections are to be stopped, "it is critical that laboratories use the approved, accurate (type-specific) blood tests that have been readily available in the US since 1999," said Brown.

The full report, "Common Use of Inaccurate Antibody Assays to Identify Status with Herpes Simplex Virus Type 2," was published in the American Journal of Obstetrics and Gynecology (2005;193(2):361-362).

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