Infectious diseases. China awakens to fight projected AIDS crisis.

Official tallies count only 670 confirmed AIDS cases and 18,143 confirmed HIV-infected people among China's 1.2 billion population. Now changing social mores, including an increase in drug use and a boom in commercial sex, combined with a tainted blood supply, have led China to the brink of an AIDS explosion. But its historic isolation also gives the country an advantage in testing the latest vaccines, as the different strains of HIV have not yet commingled there; China's well-developed public health infrastructure could also help facilitate clinical trials.