Symptoms:

Asymptomatic HIV infection, by definition, does NOT have symptoms typically associated with HIV, such as:

• Fever
• Opportunistic infections (opportunistic means they occur because the weakened immune system provides the "opportunity" for infections to take hold. Serious opportunistic infections include Pneumocystis jirovecii pneumonia, cytomegalovirus, and Mycobacterium avium).
• Oral thrush (also an opportunistic infection, but not life-threatening and does not require a seriously weakened immune system to occur)
• Weight loss

Signs and tests:

The diagnosis of HIV infection is based on standard blood tests such as the HIV antibody test (ELISA). A Western blot confirms the diagnosis.

How well an HIV-infected person's immune system is functioning can be determined by measuring the level of certain white blood cells called CD4 lymphocytes (also known as helper T lymphocytes).