this CDC report, from June 5 1981, about 5 cases of Pneumocystis Pneumonia in Los Angeles, which was the first published report about what would, a year later, be known as AIDS and would, thirty years later, have killed 25 million people.
All the above observations suggest the possibility of a cellular-immune
dysfunction related to a common exposure that predisposes individuals to
opportunistic infections such as pneumocystosis and candidiasis.
If you would like to read more about this period in history when AIDS was first being discovered and invesitagted then Randy Shilts book, And the Band Played On, is thoroughly recommended:
"An exhaustive account of the early years of the AIDS crisis, this
outlines the medical, social and political forces behind the epidemic's
origin and rapid spread. The book stands as a definitive
reminder of the shameful injustice inflicted on this nation by the
institutions in which we put our trust." Publishers Weekly