These scientists have lurid imaginations, don't they? It says the lice may have crossed over 'during fights, sex, sharing of clothes or perhaps cannibalism'. Not during peaceful trade, then? Neighbourly barbecue? Village fete? 'Save the Erectus' charitable mission?
The 'smoking louse'. A study at the University of Utah shows that only one of the two lice species on current Homo Sapiens evolved on us. This proves contact with earlier human species - perhaps Homo Erectus.