STD Quarterly-Get a handle on herpes with these new tests
Testing options for herpes simplex virus (HSV) have expanded in the United States, with three companies now offering new diagnostic methods.
The American Social Health Association (ASHA) in Research Triangle Park, NC, reports an estimated 25% of U.S. adults have genital herpes. The most serious risk is the transmission of virus from infected mother to infant during birth, resulting in death or permanent impairment.
Given the increasing prevalence of infection and the increased availability of testing, there is no excuse for not offering serologic testing, says Terri Warren, RN, MS, owner of Westover Heights Clinic in Portland, OR, and medical director of ASHA's Portland herpes support group.
"We can do syphilis tests all day long and never come up with a positive; we haven't had a positive [here] in six years now," Warren says. "One in four people is positive for herpes, so it seems like if we're not taking advantage of the new serologic testing that is available that is type-specific, then we are really missing the boat."
Serologic tests defined
Providers often use serologic tests when patients are at risk for the disease but don't have visible symptoms. In the past, type-specific blood tests were not always accurate because they confused other herpes virus antibodies such as varicella zoster (chicken pox) and Epstein Barr (mononucleosis) for herpes simplex (types 1 and 2) antibodies. The new tests offer improved sensitivity and specificity. The Western blot, developed by researchers at the University of Washington in Seattle, continues as the current gold standard for the diagnosis of herpes antibodies. While it is commercially available from several sites, its cost ($80 to $100) has limited its use.
The POCkit HSV-2 Rapid Test, the first point-of-care test for the specific detection of antibodies to the HSV-2 virus, received Food and Drug Administration approval in August 1999. Now available on the U.S. market, it is manufactured by Diagnology in Research Triangle Park, NC.
A patient with genital symptoms such as lesions, rashes, or other irritation or with a high-risk sexual history can be tested rapidly and accurately for HSV-2 infection with the POCkit test, says Tom Zietlow, director of technical affairs at Diagnology. The test can be performed in the office from a simple fingerstick, with 10-minute results allowing the clinician to begin herpes management immediately, regardless of the symptoms. Response from patients has been "overwhelmingly positive," says Zietlow. "The accuracy [of the test] and being able to get results immediately have greatly benefited many people," he notes. "We receive many calls daily from patients wanting the test and asking for local clinics or physicians whom they can contact."
The list price of the POCkit HSV-2 Rapid Test is $290 per tower of five kits for a per-kit cost of $58, Zietlow says. Discounts are available for publicly funded clinics and other facilities that likely would use a high volume of tests; such companies are encouraged to contact the company for a formal quote.
Check Meridian's tests
Meridian Diagnostics of Cincinnati offers two diagnostic tests for the herpes simplex virus. The company received FDA clearance in July 1999 for its Premier Type-Specific HSV-1 IgG ELISA Test and Premier Type-Specific HSV-2 IgG ELISA Test, which distinguish HSV-1 and HSV-2 infections
via serological blood test methods. Both are developed for use in the clinical laboratory setting.
"There still is a segment of the medical community who may be in the learning process," says Marlene Jinks, company spokeswoman. "There is still some educational work that has
to be done as to why it is necessary to do type-specific testing." Presentations continue at several professional association meetings, including the recent Clinical Virology Symposium sponsored by the Pan American Society for Clinical Virology in Clearwater, FL.
Providers may be familiar with the tests as those developed by Gull Laboratories in Salt Lake City; Meridian acquired the company and launched the products, says Jinks. The list price is $320 for 96 tests, she says. Costs to providers will depend on processing fees added by the laboratories performing the tests, she notes.
The latest FDA approvals for HSV testing come for products developed by MRL Diagnostics of Cypress, CA. The company has received clear-ance to market its type-specific HSV ELISA kits for HSV-1 and HSV-2 IgG antibodies in human serum, as well as its HSV-1 and HSV-2 Differentiation Immunoblot IgG Kit, which is designed for use as a reflex test for patient's serum previously determined to have antibodies to HSV-1 and/or HSV-2. The Immunoblot kit can differentiate HSV-1 and HSV-2 from the same specimen and is the only test of its kind on the market, says company spokeswoman Mary Beth Carpenter.
Pricing will vary depending on test volume; however, list price for a single patient result, including controls for laboratories performing 20 to 80 samples per kit, are $3.75 to $15 per test for the HSV-1 ELISA, $4.50 to $18 per test for the HSV-2 ELISA, and $17 per sample for the HSV-1/HSV-2 Immunoblot. Discount prices can be obtained by contacting the sales department.
• Tom Zietlow, Technical Affairs Department, Diagnology, P.O. Box 14643, Research Triangle Park, NC 27709-4643. Phone: (877) 776-2548. Fax: (919) 460-0459. E-mail: info@ diagnology.com. Web: www.diagnology.com.
• Marlene Jinks, Marketing Department, Meridian Diagnostics, 3471 River Hills Drive, Cincinnati, OH 45244. Phone: (513) 271-3700, ext. 336. Fax: (513) 272-5432. Web: www. meridiandiagnostics.com.
• Mary Beth Carpenter, Marketing Communications Department, MRL Diagnostics, 10703 Progress Way, Cypress, CA 90630. Phone: (800) 445-0185 or (714) 220-1900. Fax: (714) 220-1683. E-mail: email@example.com. Web: www.mrlinfo.com.
• Community Services, Department of Laboratory Medicine, University of Washington, P.O. Box 15246, Seattle, WA 98115. Phone: (800) 713-5198 or (206) 598-6066. Fax: (206) 598-6189. Web: www.depts.washington.edu/labweb/ Division/Commserv.