What does the presence of antibodies against HIV indicate?

The presence of antibodies against HIV indicates previous exposure to the virus. When a person is infected with HIV, their immune system responds by producing antibodies specific to the virus as part of the adaptive immune response. These antibodies can be detected using various testing methods, such as ELISA or western blot, usually several weeks to months after the initial infection.

It's important to note that the detection of antibodies does not confirm an active infection or the virus's current replication status, as antibodies can remain in the system long after the initial infection. Therefore, while the presence of antibodies confirms that a person has been exposed to HIV at some point, it does not provide information about whether the virus is currently present in an active form or about the immediate risk of developing AIDS, which depends on various factors such as the individual's overall health and the CD4 cell count.