Deciding where to conduct rapid HIV testing depends on a number of factors, including logistics in the labor and delivery unit, availability of trained staff, the capacity of the laboratory to consistently convey rapid HIV test results quickly (optimally in less than 60 minutes),¹⁰ and the Clinical Laboratory Improvement Act (CLIA) categorization of the test device. The OraQuick Rapid HIV-1 Antibody Test is designated by CLIA as waived and can be performed in the labor and delivery unit; the Reveal Rapid HIV-1 Antibody Test is designated under CLIA as moderate-complexity and must therefore be performed in a laboratory.

Point-of-care testing requires training and continual supervision to ensure competent and proficient testing. This requirement can pose a challenge, especially if staff turnover is high. When rapid testing is performed in the laboratory, attaining consistently prompt results requires the availability of 24-hour staff responsive to the urgent need for immediate HIV test results. Choosing the location for rapid testing may be best accomplished after a needs assessment during labor and delivery and consultation with the hospital’s point-of-care testing committee. (See section IV for the training essentials for point-of-care testing.) The College of American Pathologists Commission on Laboratory Accreditation has published a point-of-care testing checklist, which is used as part of its accreditation process. The checklist, which may help to guide the point-of-care testing process in labor and delivery settings, is available at http://www.cap.org/apps/docs/laboratory_accreditation/
checklists/point_of_care_testing_december2003.pdf

B. Interpretation of Test Results: What Does a Positive Rapid HIV Test Result Mean?

The accuracy of diagnostic tests is expressed in terms of sensitivity and specificity, as well as the positive and negative predictive value of the test result. No test is both 100% sensitive (no false-negative test results) and 100% specific (no false-positive test results). Screening tests are designed to be highly sensitive to ensure that no infected person is missed. The price for this high sensitivity is a slightly reduced specificity, that is, some women who are not infected with HIV will have false-positive HIV screening test results. In addition, the positive predictive value of a test depends on the prevalence of the condition in the group being screened. In a setting where prevalence is high, a positive result from a screening test is much more likely to reflect the person’s true status than is a positive result in an area of low prevalence, where a higher percentage of positive results will be false-positives. In all settings, a positive rapid HIV test result is a preliminary positive result that requires confirmation.

Provisions, therefore, must be made to confirm all preliminary positive rapid HIV test results, as soon as possible, with a supplemental test such as the Western blot or immunofluorescent assay (IFA). However, such testing can take several days or more and does not satisfy the need for timely HIV test results for women in labor. Thus, even in optimal rapid testing programs, some women who are not infected will receive ARV prophylaxis on the basis of a false-positive result from a rapid HIV test. The seriousness of the psychological effect of such a result is self-evident. However, a short course of the ARV prophylaxis currently recommended by the US Public Health Service has no known long-term safety effects for women and infants who are not infected.¹¹ Observational studies and clinical trials have shown that when ARV prophylaxis is administered during labor or within the first 12 hours after birth, the risk of perinatal HIV transmission is reduced from 25% to 9%–13%.^2-6 In addition, diagnosing HIV infection during labor and delivery provides a window of opportunity to offer infected women referral and treatment for their own care.

C. Importance of System to Ensure Labor Staff Access to Prenatal HIV Test Results

Experience at several hospitals has shown that HIV testing has often been done during the prenatal period but that results have not been available to labor and delivery staff. The lack of access to prenatal test results thus leads to unnecessary rapid testing and increases the potential for false-positive results and unnecessary ARV prophylaxis. During planning for the implementation of a protocol for rapid testing during labor, it is critical to ensure that all results of HIV testing during pregnancy are documented in the woman’s prenatal record and readily available to labor and delivery staff. Ensuring the availability of prenatal results may require coordination with other antenatal health care facilities to make sure that the pregnant woman signs a medical release and that her prenatal records are routinely and promptly transferred to the delivery facility before the woman’s due date.

D. Choosing the Type of Rapid HIV Testing to Use

Four rapid tests approved by the U.S. Food and Drug Administration (FDA) can provide rapid results during labor and delivery: the OraQuick Rapid HIV-1 Antibody Test (OraSure Technologies, Inc., Bethlehem, Pennsylvania), the Reveal Rapid HIV-1 Antibody Test (MedMira Laboratories, Inc., Halifax, Nova Scotia), the Uni-Gold Recombigen HIV Test (Trinity Biotech Plc., Co Wicklow, Ireland) and the Murex-SUDS-Single Use Diagnostic System HIV-1 Antibody Test (Abbott Laboratories, Abbott Park, Illinois). The SUDS test is not longer available because manufacture was discontinued in 2003.

When selecting a rapid HIV test for use during labor and delivery, it is important to consider the accuracy of the test and the location within the institution at which testing will be performed. Tests that require serum or plasma (i.e., Reveal and SUDS) are more suitable for use in the laboratory because of the need to centrifuge the blood specimen, whereas tests that can be performed with whole blood (e.g., OraQuick, Uni-Gold) without specimen processing are more easily performed in the labor and delivery unit. The sensitivities and specificities, according to clinical licensure data submitted to the FDA, are shown in Table 1.

Table 1. FDA-approved Test Performance, by Specimen Type*

Test	Specimen Type	Sensitivity, % (95% C.I.)	Specificity, % (95% C.I.)	CLIA complexity
OraQuick	Whole blood**	99.6 (98.5-99.9)	100 (99.7-100)	Waived
	Serum	—	—	—
	Plasma	—	—	—
	Oral Fluid	—	—	—
Reveal	Whole blood	—	—	—
	Serum	99.8 (99.2-100)	99.1 (98.8-99.4)	Moderate
	Plasma	99.8 (99.0-100)	98.6 (98.4-98.8)	Moderate
Uni-Gold	Whole blood^	100 (99.5-100)	99.7 (99.0-100)	Moderate
	Serum	100 (99.5-100)	99.8 (99.3-100)	Moderate
	Plasma	100 (99.5-100)	99.8 (99.3-100)	Moderate
SUDS	Whole blood	—	—	—
	Serum	99.9 (—)	99.6 (—)	Moderate
	Plasma	99.9 (—)	99.6 (—)	Moderate