A fourth measles case has been confirmed in Los Angeles County, with officials urging the community to take precautions. The resident recently traveled internationally and arrived at LAX on Feb. 9 and visited several public locations in LA county while infectious, according to the Los Angeles County Public Health Department .  Officials said people who were at Terminal B on Feb. 9 from 7:30 p.m. to 9:40 p.m. may have been exposed. In addition, passengers seated near the infected traveler will