Warning:

This document is being maintained for historical purposes, but is now out of date. To view current guidelines please visit:

• STD Treatment Guidelines   at http://www.cdc.gov/STD/treatment

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1993 Sexually Transmitted Diseases Treatment Guidelines

09/24/1993

SUGGESTED CITATION
Centers for Disease Control and Prevention. 1993 Sexually
transmitted diseases treatment guidelines. MMWR 1993;42(No. RR-14):
{inclusive page numbers}.

CIO Responsible for this publication:
National Center for Prevention Services,
Division of Sexually Transmitted Diseases and HIV Prevention

Diagnostic Testing for HIV-1 and HIV-2
     
     HIV infection is most often diagnosed by using HIV-1 antibody
tests. Antibody testing begins with a sensitive screening test such
as the enzyme-linked immunosorbent assay (ELISA) or a rapid assay.
If confirmed by Western blot or other supplemental test, a positive
antibody test means that a person is infected with HIV and is
capable of transmitting the virus to others. HIV antibody is
detectable in greater than or equal to 95% of patients within 6
months of infection. Although a negative antibody test usually
means a person is not infected, antibody tests cannot rule out
infection that occurred less than 6 months before the test.

     Since there is transplacental passage of maternal HIV
antibody, antibody tests for HIV are expected to be positive in the
serum of both infected and uninfected infants born to a
seropositive mother. Passively acquired HIV antibody falls to
undetectable levels among most infants by 15 months of age. A
definitive determination of HIV infection for an infant less than
15 months of age should be based either on the presence of antibody
to HIV in conjunction with a compatible immunologic profile and
clinical course or on laboratory evidence of HIV in blood or
tissues by culture, nucleic acid, or antigen detection.

     Specific recommendations for the diagnostic testing of HIV are
listed below:

--   Informed consent must be obtained before an HIV test is
     performed. Some states require written consent. See HIV Prevention
     Counseling for a discussion of pretest and posttest counseling.

--   Positive screening tests for HIV antibody must be confirmed by
     a more specific confirmatory test (either the Western blot assay or
     indirect immunofluorescence assay {IFA}) before being considered
     definitive for confirming HIV infection.

--   Persons with positive HIV tests must receive medical and
     psychosocial evaluation and monitoring services, or be referred for
     these services.

     The prevalence of HIV-2 in the United States is extremely low,
and CDC does not recommend routine testing for HIV-2 in settings
other than blood centers, unless demographic or behavioral
information suggests that HIV-2 infection might be present. Those
at risk for HIV-2 infection include persons from a country in which
HIV-2 is endemic or the sex partners of such persons. (As of July
1992, HIV-2 was endemic in parts of West Africa and an increased
prevalence of HIV-2 had been reported in Angola, France,
Mozambique, and Portugal.) Additionally, testing for HIV-2 should
be conducted when there is clinical evidence or suspicion of HIV
disease in the absence of a positive test for antibodies to HIV-1
(6).

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