On June 5, 1981, a mysterious illness killed five men in Los Angeles. Those were the first cases of what would later be known as Acquired Immune Deficiency Syndrome or AIDS.

Thursday marked the 23rd annual World AIDS Day.

In the United States alone, 1.2 million Americans are living with HIV and there are 50,000 new infections every year.

In a World AIDS Day speech, President Barack Obama renewed the U.S. commitment to ending HIV and AIDS.

"The rate of new infections may be going down elsewhere, but it's not going down here in America," he said. "There are communities in this country being devastated still by this disease. When new infections among young, black, gay men increase by nearly 50 percent in three years, we need to do more to show them that their lives matter."

Regina Hopewell is director of the Compassion International AIDS initiative. Below she discusses what the ministry is doing to help HIV and AIDS patients.

In Sydney, landmarks were lit in red in honor of the day. Dignitaries and health officials gathered to help raise awareness.

"It is because we want it to be so, and we will strive with everything to make it so that AIDS will be eradicated from the face of the earth," said Quentin Bryce, governor general of the Commonwealth of Australia.

There have already been significant gains in the fight against AIDS.

The United Nations recently announced that in 2010, new HIV infections and AIDS-related deaths were at their lowest levels since the epidemic peaked.

But this year, leaders are aiming higher -- to have an AIDS free generation by 2015.