HIV-1/2 Exposure Screen

Test Code: EXPOSE

Overview
Ordering
Specimen
Performing
Clinical/Interpretive
Contacts
Coding

Useful For

Identifying HIV infection in:
- the source patient involved in an exposure incident with a healthcare worker.
- OB patients with unknown HIV serostatus at time of delivery.

Do not order this test for the routine determination of HIV serostatus: Use HIV-1,2 Ab/Ag by EIA with Confirmation. (Test Code: HIVR).

Specimen Requirements

Fasting Required	Specimen Type	Preferred Container/Tube	Acceptable Container/Tube	Specimen Volume	Specimen Minimum Volume (allows for 1 repeat)	Pediatric Minimum Volume (no repeat)
No	Plasma	EDTA Pink Top Tube (PTT)	EDTA Lavender Top Tube (LTT)	1.0 mL	0.5 mL

Collection Processing Instructions

· Centrifugation and refrigerated/frozen storage must occur within 24 hours of collection for either

sample type.

· EDTA plasma samples may be centrifuged immediately after collection.

· If serum is inadvertently collected (see note below), complete clot formation should take place before centrifugation.

· After centrifugation, physically separate plasma/serum from the red cells and send aliquot for analysis.

· Specimens must be free of particulate matter including fibrin.

Note: Serum can only be used for initial HIV testing, it cannot be used for Mayo HVDIP confirmation

testing of REACTIVE samples.

· Specimens are stable for 24 hours at room temperature, this includes pre- & post- centrifugation time, separated or unseparated from red cells.

· Store plasma/serum specimens at 2–8°C if not tested within 24 hours of collection. Separated specimens are stable for 14 days at 2–8ºC.

· For longer storage, plasma/serum may be frozen for 8 months at -20ºC or colder. Samples may undergo up to 5 freeze/thaw cycles.

· Frozen samples must be completely thawed, thoroughly mixed, and centrifuged before analysis.

· For U-have testing, specimens are stable in primary tubes up to 14 days at 2–8°C (this includes plasma stored on packed red cells, serum stored on the clot, and specimens processed and stored in gel barrier blood collection tubes).

If REACTIVE, Mayo Medical Labs will require an additional 1 mL of EDTA plasma.

Specimen Stability Information

Specimen Type	Temperature	Time
Plasma	Ambient	24 hours
	Refrigerate	14 days
	Freeze (-20C)	8 months

Rejection Criteria

Grossly icteric specimens are uninterpretable due to high background
Specimens containing precipitate
Cadaver specimens
Heat-inactivated specimens
Body fluids other than serum
Samples stored at room temperature for longer than 24 hours, this includes pre- and post- centrifugation time.
Samples stored for longer than 14 days at 2–8°C.
Specimens with obvious microbial contamination.

Performing Laboratory Information

Performing Location	Day(s) Test Performed	Analytical Time	Methodology/Instrumentation
Beaver Dam	Monday through Sunday	2 hours	Sandwich Chemilumonometric IA/Siemens Centaur
Weston	Monday through Sunday	2 hours	Lateral flow immunoassay/Trinity Biotech Uni-Gold™ Recombigen® HIV-1/2 Rapid Test
Eau Claire	Monday through Sunday	2 hours	Lateral flow immunoassay/Trinity Biotech Uni-Gold™ Recombigen® HIV-1/2 Rapid Test
Rice Lake	Monday through Sunday	2 hours	Lateral flow immunoassay/OraQuick ADVANCE® HIV-1/2 Rapid Test
Marshfield	Monday through Sunday	2 hours	Sandwich Chemilumonometric IA/Siemens Centaur
Neillsville	Monday through Sunday	2 hours	Lateral flow immunoassay/OraQuick ADVANCE® HIV-1/2 Rapid Test
Minocqua	Monday through Sunday	2 hours	Sandwich Chemilumonometric IA/Siemens Centaur
Park Falls	Monday through Sunday	2 hours	Lateral flow immunoassay/OraQuick ADVANCE® HIV-1/2 Rapid Test

Reference Range Information

Performing Location	Reference Range
All Performing Sites	Non-reactive

Interpretation

Western blot analysis is no longer recommended for confirmation of HIV EIA antibody-positive results. Confirmation of HIV 1,2 antibody testing will be done by Mayo Medical Labs. This test algorithm closely follows the current CDC recommendations for HIV diagnosis. (See Centers for Disease Control and Prevention. Detection of Acute HIV Infection in Two Evaluations of a New HIV Diagnostic Testing Algorithm — United States, 2011–2013. MMWR 2013;62:489-494.)

Outreach CPTs

CPT	Modifier (if needed)	Quantity	Description	Comments
87389		1	HIV-1 Ag(s), with HIV-1 and HIV-2 Abs single result	For testing performed at Marshfield
86703	92	1	HIV-1 and HIV-2 Abs single result	For testing performed at Regional Center Labs

Ordering Applications

Ordering Application	Description
Cerner	HIV-1/2 Exposure Screen

If the ordering application you are looking for is not listed, contact your local laboratory for assistance.