Roberto Giraldo is a laboratory technologist in the molecular diagnostics laboratory at the New York Presbyterian Hospital, and an HIV denialist. He is, to emphasize, not licensed to practice medicine in New York, nor an academic researcher, but some people have thought that he is – as expected – not entirely clear about that on his own website. His screeds at least display a truly staggering scientific ignorance, but that, of course, has not prevented them from being frequently parroted on other denialist websites. His lunatic ignorance is described in more detail here. Giraldo also has the honor of being the former president of the denialist organization “Rethinking AIDS”.
Given his complete lack of expertise Giraldo is (or at least was per 2005) a member of the South African Presidential AIDS Advisory Panel. AIDS in South Africa is still a rapidly growing epidemic, and millions and millions of people have died over the last decades, largely because the government has refused to accept science and evidence for how it works and how it should be treated. Giraldo recommends that HIV+ patients take a mixture of olive oil, lemon juice, garlic, and African potato. His recommendations have not helped thus far, and there are reasons for that.
There is some useful information on HIV-denialism as denialism here.
Diagnosis: Giraldo had the potential of just being your regular barely coherent conspiracy theory nutjob and dunderhead. But HIV denialism is far, far more insidious than sacred geometry or astrology, especially since the prevalence of denialist nuttery in Africa provides these people with an opportunity to actually cause some serious damage.