Is the "AIDS Test" Accurate?
Many people are surprised to learn that there is no such thing as a test
for AIDS. The tests popularly referred to as "AIDS tests" do not identify
or diagnose AIDS and cannot detect HIV, the virus claimed to cause AIDS.
The ELISA and Western Blot tests commonly used to diagnose HIV infection
detect only interactions between proteins and antibodies thought to be
specific for HIV -- they do not detect HIV itself. And contrary to popular
belief, newer "viral load" tests do not measure levels of actual virus in
the blood.
All HIV antibody tests are highly inaccurate. One reason for the tests'
tremendous inaccuracy is that a variety of viruses, bacteria and other
antigens can cause the immune system to make antibodies that also react
with HIV. When the antibodies produced in response to these other
infections and antigens react with HIV proteins, a positive result is
registered. Many antibodies found in normal, healthy, HIV-free people can
cause a positive reading on HIV antibody tests. (23) Since the antibody
production generated by a number of common viral infections can continue
for years after the immune system has defeated a virus -- and even for an
entire lifetime -- people never exposed to HIV can have consistent false
positive reactions on HIV tests for years or for their entire lives.
The accuracy of an antibody test can be established only by verifying that
positive results are found in people who actually have the virus. This
standard for determining accuracy was not met in 1984 when the HIV
antibody test was first created. Instead, to this day, positive ELISAs are
verified by a second antibody test of unknown accuracy, the HIV Western
Blot. Since the accuracy for HIV antibody tests has never been properly
established, it is not possible to claim that a positive test indicates a
current, active HIV infection or even to know what it may indicate. (24)
In one study that investigated positive results confirmed by Western Blot,
80 people with two positive ELISAs that were "verified" by a positive
Western Blot tested negative on their next Western Blot. (25)
Antibodies produced in response to simple infections like a cold or the
flu can cause a positive reaction on an HIV antibody test. A flu shot and
other immunizations can also create positive HIV ELISA and Western Blot
results. Having or having had herpes or hepatitis may produce a positive
test, as can vaccination for hepatitis B. Exposure to microbes such as
those that cause tuberculosis and malaria commonly cause false positive
results, as do the presence of tapeworms and other parasites. Conditions
such as alcoholism or liver disease and blood that is altered through drug
use may elicit the production of antibodies that react on HIV antibody
tests. Pregnancy and prior pregnancy can also cause a positive response.
The antibodies produced to act against infection with mycobacterium and
yeast, infections which are found in 90% of AIDS patients, cause false
positive HIV test results. (26) In one study, 13% of Amazonian Indians who
do not have AIDS and who have no contact with people outside their own
tribe tested HIV positive. (26) In another report, 50% of blood samples
from healthy dogs reacted positively on HIV antibody tests. (27)
Prior to the notion that HIV causes AIDS, viral antibodies were considered
a normal, healthy response to infection and an indication of immunity.
Antibodies alone were not used to diagnose disease or predict illness.
Before HIV, only ELISA and Western Blot tests that had been shown to
correspond with the finding of actual virus were used to diagnose viral
infections. There is no credible scientific evidence to suggest that these
rules should be disregarded to accommodate HIV.
In addition to being inaccurate, HIV antibody tests are not standardized.
This means that there is no nationally or internationally accepted
criteria for what constitutes a positive result. Standards also vary from
lab to lab within the same country or state, and can even differ from day
to day at the same lab. (28) As HIV test kit manufacturers acknowledge,
"At present there is no recognized standard for establishing the presence
or absence of antibodies to HIV-1 and HIV-2 in human blood." (29)
The following chart illustrates just some of the varying criteria for what
is considered a positive HIV Western Blot, and shows how someone could
actually switch from positive to negative simply by changing countries.
The differing standards for positive HIV tests are not limited to the
locations and agencies mentioned here -- criteria vary from lab to lab and
results are open to interpretation. An inconclusive test can become
positive or negative based on an individual's sexual preference, health
history, zip code or other survey data.
The various proteins used in HIV Western Blot tests are arranged into
bands that are divided into three sections. These three sections are
represented by the abbreviations ENV, POL and GAG. Proteins in the ENV
section correspond to the outer membrane or "envelope" of a virus; POL
refers to proteins common to all retroviruses which include polymerase and
other enzymes; GAG stands for "group specific antigen" and includes
proteins that form the inner core of a virus. The protein bands in each
section are indicated by the letter "p" and are followed by a number which
describes the molecular weight of that protein measured in daltons. For
example, p160 is an ENV protein that weighs 160 daltons.
It is important to note that none of the proteins used in HIV antibody
tests are particular to HIV, and none of the antigens said to be specific
to HIV are found only in persons who test HIV positive. In fact, many
people diagnosed HIV positive do not have these "HIV antigens" in their
blood.
As mentioned previously, newer HIV "viral load" tests do not isolate or
measure actual virus. The tests' manufacturers clearly state that viral
load "is not intended to be used as a screening test for HIV or as a
diagnostic test to confirm the presence of HIV infection." (31) In fact,
viral load tests have not been approved by the FDA for diagnostic purposes
and have not been verified by virus isolation. For more information on
viral load tests, please see What's Up With Viral Load? on page 36. Of
course, the most outstanding problem with any HIV test is that HIV has
never been demonstrated to cause AIDS.
Defined Terms
Antigen: A substance that can trigger an immune response, resulting in the
production of antibodies as part of the body's defense system against
infection and disease. Many antigens are foreign proteins (those not found
naturally in the body); they include microorganisms, toxins, and tissues
from another person used in organ transplantation. Antigen stands for
ANTIbody GENerating.
False Positive: Indicates infection where none exists.