ochlesis

from The Collaborative International Dictionary of English v.0.48

Ochlesis \Och*le"sis\, n. [NL., fr. Gr. ? disturbance, fr.
   'o`chlos crowd, mob.] (Med.)
   A general morbid condition induced by the crowding together
   of many persons, esp. sick persons, under one roof. --G.
   Gregory.
   [1913 Webster]