Fight AIDS through more effective whoring

Came across this bit of news buried in a story of a prostitute-turned-author in India:

Commercial sex is one of the main drivers of the spread of HIV/AIDS and India has more than 5 million reported cases of people living with the virus, rivalling South Africa as the worst hit nation.

The U.S. Central Intelligence Agency estimates more than 20 million people could be infected with HIV in India by 2010 and economists warn it could undermine India's rise to economic superpower status.

Alarmed by the rising numbers, the government's Planning Commission has recommended prostitution be legalized to help fight AIDS.

Does anyone care to explain how legalizing prostitution will help fight AIDS? How about enforcing the laws against it?