Human Immunodeficiency Virus infection (HIV), also called Acquired Immunodeficiency Syndrome (AIDS), is a disease of the immune system caused by the immunodeficiency virus (HIV). HIV denotes the initial infection. AIDS refers to the confirmation and the advanced stage of the disease.

Many people living with HIV have no signs and symptoms at all. The disease may go unnoticed with no apparent symptoms for a long time, even years. The signs and symptoms of this disease are caused by opportunistic infections and can be easily confused with other symptoms that are common to other diseases. For instance, first symptoms are usually similar to a simple flu. The disease progressively damages the immune system, making it vulnerable against those opportunistic diseases and infections.

The virus develops specific antibodies within three to twelve weeks of the initial infection and can be transmitted through:

- Blood transfusions

- Sexual intercourse

- Contaminated elements reaching the blood stream (like needles)

- Pregnancy (from mother to child)

- Breastfeeding

-         Acute or Primary Infection. It starts several weeks and up to 3 months after exposure. This stage is characterized by flu-like symptoms. These symptoms are known as Acute Retroviral Syndrome (ARS).

-         Clinical Latency. Also called Chronic. The virus becomes less active. Usually, this period is asymptomatic during several years.

-         AIDS. This is the advanced stage where a weakened immune system allows opportunistic infections to attack the body.

There is no way to know solely by symptoms if a person is infected with HIV. The disease is diagnosed after conclusive results come from:

-    PCR (Polymerase Chain Reaction) test for HIV, and