The conference will be opened on Sunday by former Brazilian President Fernando Henrique Cardoso, whose country has the most successful anti-AIDS programme among developing nations.
Brazil distributes drugs free of charge and produces its own generic antiretroviral compounds.
Former South African President Nelson Mandela will speak about Africa’s battle with AIDS on Monday, while Europe’s own proposals for fighting the disease will be presented on Wednesday by French President Jacques Chirac and EU Commission President Romano Prodi.
“We estimate that among the 40 million people infected worldwide, there are between 6 to 9 million that need to be treated urgently to avoid death,” said Michel Kazatchkine, director of the French National Agency on AIDS Research.
Bush promised $15 billion for AIDS
US President George W. Bush called on Congress on Saturday to fully fund his $15 billion plan to combat the disease and make anti-viral treatment available to about 2 million HIV-infected people in Africa and the Caribbean.
While many scientists have praised Bush for pledging steps to battle the disease that is killing more than 8,000 people per day, some worry that the United States will not fulfill its promises quickly.
"We're concerned the president is designing his trip to be a victory lap around the continent with photo-ops and empty rhetoric," said Dr. Paul Zeitz, executive director of the Global AIDS Alliance, referring to Bush’s African tour which ended on Saturday.
The United States filed a complaint with the World Trade Organization in 2001 against Brazil for passing a law that would give patent protection only to AIDS drugs produced locally.
Many scientists and activists believe Washington's challenge threatens Brazil's free AIDS drugs policy.
The deadly HIV virus that causes AIDS has infected close to 30 million people in Africa alone.
Experts believe about 4 million need drugs that can keep patients alive for years by suppressing the virus. Only about 50,000 receive such therapy now, as prices have been out of reach for most Africans.