In both clinical practice and guideline development, doctors need to get better at saying "I don't know".

In 2010 the World Health Organisation (WHO) changed the HIV treatment guidelines for poor countries and recommended switching from stavudine (D4T) to tenofovir disoproxil fumarate (TDF) for all patients on first line treatment. Stavudine (D4T) was previously one of three antiretroviral drugs (ARVs) recommended as first-line treatment but serious side effects, seen in many studies and treatment programmes, led to calls to use better, less toxic drugs.

HIVEX limited used to offer an unproven electromagnetic therapy as a treatment for HIV at a facility in Durban. Following pressure from various quarters, this facility has recently been closed down.

Clinicians and AIDS workers have condemned Imuniti Holdings for claims it is making about its nutritional supplements.

AIDS denialist Celia Farber sued Richard Jefferys for calling her a liar. In November, the Supreme Court of New York dismissed Farber's action. Quackdown interviewed Richard about the case. The interview is fascinating because Richard crisply describes the web of lies, homophobia and madness in the world of AIDS denialism.

The obscure Italian Journal of Anatomy and Embryology has published an article by AIDS denialist Peter Duesberg packed with errors. It claims that data from Uganda and South Africa shows that there is no evidence of an HIV epidemic. This journal, whose title indicates no expertise in HIV, has a track record of publishing peer-reviewed AIDS denialist nonsense.

The Western Cape government has implemented a lottery to encourage people to get tested for HIV. People who get tested can enter the lottery and win large cash prizes. In the fiery world of Cape Town politics, there has been much vitriol from both supporters and detractors of the lottery. But what does science show about incentives for HIV testing?

We take issue with Premier Helen Zille's views on HIV transmission, criminalisation and who deserves treatment. This is an expanded version of an article that was published in The Cape Argus on 15 November 2011.

The most prolific claim of alternative medicine products must surely be that they boost the immune system. I have a collection of products purchased from Discom making this claim. You'll find immune boosters in almost any pharmacy including, or perhaps especially, the large retail chains. Even big pharmaceutical companies like Boehringer Ingelheim and Cipla sell immune boosters. But what is an immune booster? And do these products really improve your immunity against disease?

Surveys, done properly, can tell us important things about people's beliefs, attitudes and behaviour. But when they are done badly, as they often are, they perpetuate confusion and myths. One recent survey on youth attitudes to sex and HIV, announced with much fanfare, was so poor that its results are meaningless. And several journalists reported the survey without a hint of criticism.