Answer :
The lines "The camp looked as though it had been through an epidemic: empty and dead. Only a few "well-dressed" inmates were wandering between the blocks." from the book "Night" by Elie Wiesel describe how the new camp appeared to Elie.
The new camp that Elie talks about in these lines is the Buna concentration camp where he and his father had recently been brought. The camp appears to him as if it had been through an epidemic as many of the inmates mostly old men and children have been sent to the chimney or crematorium to be burnt alive to death.