Ghettoization was deliberate plan by the Germans to concentrate as many Jews as possible in as small an area as possible prior to their being deported to the death camps. If any of them became ill or starved to death , so much the better.They SS didn’t give damn about the health and hygiene of any Jew in the ghetto.
I am talking before WWIi, in the 18th and 19th century ghettos. This stuff had long been going on.