STD Quarterly: Company to resume shipping HIV test kits

The company that manufactures one of the two HIV-1 Western blot (WB) kits licensed by the Food and Drug Administration (FDA) for supplemental testing of serum, plasma, and dried whole-blood spot specimens obtained for medical diagnosis or blood and plasma donor screening has announced that it has resumed production, thus averting a shortfall of the kits.

Calypte Biomedical Corp. of Alameda, CA, issued news it was winding down operations in April 2002. The Atlanta-based Centers for Disease Control and Prevention (CDC) alerted health care providers of a possible shortage of Calypte Biomedical’s Cambridge Biotech HIV-1 Western blot kit.1 Since that time, the company has received new funding and is resuming production, confirms Joe Bunning, company spokesman.

With just two FDA-approved kits for confirmatory HIV testing, public health officials have moved quickly to make sure testing options remain available. According to Thomas Hearn, deputy director of the CDC’s Public Health Practice Program Office’s Division of Laboratory Systems, the agency has remained in close communication with the FDA, the Association of Public Health Laboratories, and other private and public partners to monitor problems with test kit production, check access to test kits, monitor delays in obtaining test results, and examine data that may have had a bearing on alternative confirmatory testing strategies.

Other test targets oral fluid samples

The other Western blot test used for confirmatory purposes is the Genetic Systems Western blot kit, manufactured by BioRad Laboratories of Hercules, CA. While the OraSure HIV-1 Western blot kit made by OraSure Technologies of Bethlehem, PA, is approved for supplemental testing of oral fluid samples found reactive for antibodies to HIV-1 in screening tests performed on oral fluids, use of oral-fluid specimens is not approved for screening and supplemental testing of blood and plasma donors, according to the CDC.

The algorithm for HIV testing in the United States begins with an initial screening enzyme immunoassay (EIA). If reactive, the EIA is repeated in duplicate on the same specimen. If repeatedly reactive, the specimen is tested with a more specific supplemental test to validate the true-positive EIA results and to prevent notification based on false-positive results that might occur during the screening tests. Supplemental tests include the WB test or the indirect immunofluorescence assay (IFA). This algorithm is used with serum, plasma, dried whole-blood spots, and oral fluid specimens.

Check test options

If laboratories are unable to obtain the Cam-bridge Biotech HIV-1 Western blot kit, the CDC outlines three options1:

• Supplemental testing can be performed on serum, plasma, and dried whole-blood spots using the Genetic Systems Western blot kit. Information about the availability of the test kit is available by calling the company at (800) 224-6723, or checking its web site, www.biorad.com.

• Supplemental testing can be performed on serum, plasma, and dried whole-blood spots using the Fluorognost HIV-1 IFA kit made by Sanochemia of Vienna, Austria, and distributed by Home Access Health of Hoffman Estates, IL. To check availability of this product, call (203) 227-6880, or visit the web site www.fluorognost.com. Sanochemia provides a self-taught course on performing the HIV-1 IFA and a proficiency panel free of charge, according to the CDC.

• Patient (but not blood or plasma donor) screening for antibodies to HIV can be performed on an oral fluid specimen collected with the OraSure HIV-1 oral fluid collection device made by OraSure Technologies using an approved EIA test kit (Oral Fluid Vironostika HIV-1 MicroElisa) manufactured by bioMérieux of Durham, NC. Repeatedly EIA reactive oral fluid samples can be tested further with the supplemental OraSure HIV-1 Western blot kit.

For more information on the availability of the OraSure HIV-1 collection device, call (800) 869-3538, or visit the company’s web site, www.orasure.com. Information about the availability of the oral fluid EIA and WB kits can be obtained from bioMérieux, telephone (800)682-2666.

Reference

1. Notice to readers: Potential shortage of supplemental test kits for detecting HIV-1 antibodies. MMWR 2002; 51:395-396.