This sentence actually cracked me up!!

"With a population of around a billion, a mere 0.1% increase in HIV prevalence would increase the estimated number of people living with HIV by over half a MILLION."

Percentages inrease because number of people infected increase, but this sentence makes it look like the other way round. They should have actually said that it would need over half a million new infections to raise the percentage by 0.1. But then, that wouldnt make it sound sensational, would it?