Los Angeles County health officials say that the case was reported in a resident of El Monte and that there is no known relation between them and the other four patients.

The Los Angeles County Department of Public Health yesterday announced that it is investigating a fifth local dengue case, which doesn’t appear to be related to the four earlier cases. The latest patient is a resident of El Monte, which is located about 14 miles east of the city of Los Angeles.

Los Angeles County health officials said Wednesday a Panorama City resident is the latest case of locally acquired dengue.

Evidence is mounting that the mosquito-borne infection is circulating in the Los Angeles area for the first time.

Symptoms of dengue often mirror those of other viruses, and health officials urged healthcare providers to be vigilant.

A Panorama City resident has been confirmed with a rare locally acquired case of the mosquito-borne illness dengue, making him the fourth person in the county with the virus this year, public health officials said Wednesday.