First off
if it is actually scabies, as mentioned this seem unlikely as skin to skin contact is usually required to spread it and it is very contagious.However if it is, you dont just treat the carpets but also any soft furnishings in the same vicinity,
Also anyone who has been infected has to be treated as a matter of urgency and can not return to work until given the all clear.
It can survive in carpets for up to 3 days but does require a 'host' to survive any longer and reproduce, as mentioned
very hot water extraction will kill them but as you are not trying to clean the carpets but rid them of an infestation then dry vapour or steam will do it a lot faster with less mess and probably more effectively.
The quickest way to spread scabies is by sex, so it looks like that might have had a cracking office xmas party, wonder if it was caught on CCTV.