The news today is full of the shocking claim that half of new HIV cases in Greece were from people deliberately contracting the disease in order to claim benefits:
This fact came from a report published by the World Health Organisation, the UN's public health arm.
Except it's not true. The WHO's head of public relations tweeted that it was actually a "typo".
The statement doesn't specify exactly how the "editing error" happened, though.
The WHO say the claim was originally sourced to a reference to "accounts of deliberate self-infection by a few individuals", in this correspondence published by The Lancet. That in turn references this report, which describes self-infection as a "well-founded suspicion" about "some problem users".