The White House has lifted the HIV travel ban, and the United States is no longer included in the list of only seven countries worldwide that bar HIV-positive persons from obtaining visas for entry.  The Washington Post reports that the President described the 22 year-old ban as being "rooted in fear rather than fact" and announced the end of the rule-making process lifting the ban.

The president signed the Ryan White HIV/AIDS Treatment Extension Act
of 2009 at the White House Friday and also spoke of the new rules,
which have been under development more more than a year. "We are
finishing the job," the president said, according to the Post.

The regulations are the final procedural step in ending the ban, and
will be published Monday in the Federal Register, to be followed by
the standard 60-day waiting period prior to implementation.

The ban first came about at a time when stigma, discrimination and lack of knowledge of HIV and AIDS were prevalent.  According to the Post:

[The] ban on travel and immigration to the U.S. by individuals with HIV, the virus that causes AIDS, was first established by the Reagan-era U.S. Public Health Service and then given further support when Sen. Jesse Helms (R-N.C.) added HIV to the travel-exclusion list in a move that was ultimately passed unanimously by the Senate in 1987.

Earlier attempts to overturn the ban were foiled by conservative groups and members of Congress.  In 1993, the ban was added to immigration laws. It was finally overturned as part of the passage of a bill reauthorizing funding for the President’s Emergency Plan
for AIDS Relief (PEPFAR).  Publication of the new rules is the last step in this process