human immunodeficiency virus (HIV) test detects
antibodies to HIV or the genetic material (DNA or
RNA) of HIV in blood or another type of sample. This
determines whether an HIV infection is present (HIV-positive). ELISA results
are usually available in 2 to 4 days. Results of the other tests, such as the
Western blot or IFA, take 1 to 2 weeks.
No HIV antibodies are found. Normal results are called
If an antibody test is done during the
seroconversion period and is negative, repeat testing
is needed. Most people have antibodies to HIV within 6 months after becoming
infected. If a repeat test at 6 months is negative, there is no
PCR test to look for genetic material does not detect
any RNA or DNA of HIV.
Test results do not clearly show whether a person has an
HIV infection. This is usually called an indeterminate result. It may occur
before HIV antibodies develop or when some other type of antibody is
interfering with the results. If this occurs, a PCR test, which detects HIV RNA
or DNA, may be done to see if the virus is present.
A person who still has indeterminate results for 6 months
or longer is called "stable indeterminate" and is not considered to be infected
HIV antibodies are found. These results are called
A positive ELISA is repeated using the same blood sample.
If two or more ELISA results are positive, they must be confirmed by a Western
blot or IFA test.
A PCR test finds genetic material (RNA or DNA) of
What Affects the Test
Reasons you may not be able to
have the test or why the results may not be helpful include:
Having an antibody test done before a detectable amount of antibodies is present (during the seroconversion period).
autoimmune disease, leukemia, or