The following are from the ELISA test insert and the insert from the
Western Blot test:
"LIMITATIONS OF THE PROCEDURE (of ELISA)
The (Abbot Laboratories) [Abbot] HIVAB HIV-1 EIA antibody procedure and
the Interpretation of Results must be followed closely when testing for
the presence of antibodies to HIV-1 in plasma or serum from individual
subjects. Because the EIA was designed to test individual units of
blood or plasma, most data regarding its interpretation were derived
from testing individual samples. Insufficient data are available to
interpret tests performed on other body specimens, pooled blood or
processed plasma, and products made from such pools: testing of these
specimens is not recommended.
Abbot HIVAB HIV-1 EIA detects antibodies to HIV-1 in blood and thus is
useful in screening blood and plasma donated for transfusion and
further manufacture, in evaluating patients with signs or symptoms of
AIDS, and in establishing prior infection with HIV-1. Clinical studies
continue to clarify and refine the interpretation and medical
significance of the presence of antibodies to HIV-1. For most uses it
is recommended that repeatably reactive specimens be investigated by an
additional more specific, or supplemental test. A person who has
antibodies to HIV-1 is presumed to be infected with the virus and
appropriate counseling and medical evaluation should be offered. Such
an evaluation should be considered an important part of HIV-1 antibody
testing and should include test result confirmation on a freshly drawn
sample.
AIDS and AIDS-related conditions are clinical syndromes and their
disgnosis can only be established clinically. EIA testing alone cannot
be used to disgnose AIDS, even if the recommended investigation of
reactive specimens suggests a high probability that the antibody to
HIV-1 is present. A negative test result at any point in the
investigation of individual subjects does not preclude the possibility
of exposure to or infection with HIV-1. The risk of an asymptomatic
person with a repeatably reactive serum sample developing AIDS or an
AIDS-related condition is not known.
Data obtained from testing persons both at increased and at low risk
for HIV-1 infection suggest that repeatably reactive specimens with
high absorbance on EIA are more likely to demonstrate the presence of
the HIV-1 antibodies by additional more specific, or supplemental
testing. Reactivity at or only slightly above the cut-off value is more
frequently nonspecific, especially in samples obtained from persons at
low risk for HIV-1 infection; however, the presence of antibodies in
some of these specimens can be demonstrated by additional more
specific, or supplemental testing."
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Now from the test to confirm the above test. CONFIRM?!
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"LIMITATIONS OF THE PROCEDURE (of Western Blot)
1. The assay must be performed in strict accordance with these
instructions to obtain accurate, reproducible results.
2. Although a Positive result may indicate infection with the HIV-1
virus, a diagnosis of Acquired Immunodeficiency Syndrome (AIDS) can be
made only if an individual meets the case definition of AIDS
established by the Centers for Disease Control. A repeat test on an
independent sample should be considered to control for sample mix-up or
operator error, and to verify a positive test result.
3. Individuals with HIV-1 infection may present incomplete patterns due
to the natural history of AIDS or other immunodeficiency states, e.g.:
a. AIDS patients may lose antibody reactions to p24 & p31;
b. Infected infants may fail to seroconvert;
c. Individuals who have recently seroconverted may display incomplete
band patterns;
d. Infected patients with malignancies and individuals receiving
immunosuppressive drugs may fail to develop a Positive result;
e. Individuals infected with HTLV-I/II or HIV-2, may exhibit incomplete
cross-reactivity.
4. Since reactivity of any degree with any of the virus-specific
proteins identified on the strip is possible evidence of antibodies to
HIV-1, all samples interpreted as Indeterminate should be repeated
using the original specimen. Do not use this kit as the sole basis of
disgnosis of HIV-1 infection. In addition, it is recommended that
samples interpreted as Indeterminate be retested after six months,
using a fresh specimen.
A Negative result does not exclude the possibility of HIV-1 infection.
Antibody testing should not be used in lieu of donor self-exclusion by
blood collection establishments."