How common is HIV (human immunodeficiency virus) infection?

More than 1 million Americans have confirmed HIV infection or AIDS. The CDC believes that up to 25% of infected people in the United States do not know they are infected. An estimated 40,000 Americans are newly infected each year. According to the CDC, AIDS is seven times more prevalent in African Americans and three times more prevalent in Hispanic Americans than in Caucasian Americans.

While human immunodeficiency virus (HIV) -- the infection that causes or is presumed to cause acquired immunodeficiency syndrome (AIDS) -- has traditionally been associated with gay men and intravenous drug users, the incidence of the disease is growing in other sectors of the population. Half a million to a million and a half people in the United States are infected with HIV, with six times as many men being infected as women. Infection rates are higher in the African-American and Latino communities, presumably because of other associated risk factors, such as higher rates of drug use. And 34 to 43 million people are infected with HIV worldwide. It is a true epidemic.