<prompt> Isolation is not needed for measles due to -There are healthy carriersCarriers are convalascentsThe infectivity in diseased is lowThere are incubatory carriers  <response>: Transmission directly from person to person by droplet infection from 4 days before onset of rash until 4days thereafter. REF. PARKS TEXTBOOK OF PREVENTIVE AND SOCIAL MEDICINE 21ST EDITION. PAGE NO - 147 