A 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 negative.
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 infection.
A 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 with HIV.
HIV antibodies are found. These results are called positive.
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 HIV.
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).