By having parents who engage in high-risk behaviors and/or have it injected via unsterile punctures, as plainly discussed in the article. Homosexuals and drug-users are the primary carriers because of their behaviors. Surely you knew that, yes?
And again, so what? The bottom line is a person can get the virus through heterosexual sex. Labeling something the "Big Lie" is dangerous, in my opinion, because it tends to obscure the very real fact that, if a person has unprotected sex, it is possible to contract a fatal disease.
Every "group" in the world attempts to use scientific data to support an "agenda." Indeed, labeling research "The Big Lie" leads me to believe there is an agenda behind the article, and pure science is not it.