Health officials warned that the Los Angeles area is seeing more dengue fever cases in people who have not traveled outside the U.S. mainland, a year after the first such case was reported in California.

The Los Angeles area is seeing more cases of people with dengue fever without traveling outside the United States, a year after the first such case was reported in California.

Los Angeles health officials announced they are investigating a handful of locally acquired dengue fever cases in the city of Baldwin Park.

While Los Angeles County is reporting three locally acquired cases of dengue this year -- which is rare for the region -- there have been at least 3,085 cases nationally of locally acquired virus so far this year,

LA County health officials warned about an "unprecedented" cluster of dengue cases after two more people in Baldwin Park tested positive.