What were some of the first reported cases of the HIV virus?

In June of 1981, the Centers for Disease Control and Prevention reported five cases of a rare pneumonia, Pneumocystis carinii pneumonia, in gay men in Los Angeles, according to AIDS.gov. Other rare infections in combination with the pneumonia suggested that their immune systems were failing for unknown reasons.

As other reported cases similar to these five in Los Angeles began to surface, including immune system failure resulting in multiple infections within each patient, a syndrome was characterized called acquired immune deficiency syndrome, or AIDS, states AIDS.gov. In 1984, the retrovirus HTLV-III was found to be the cause of AIDS, which is now referred to as HIV, or human immunodeficiency virus.