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.

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

Los Angeles County health officials Thursday continue to investigate a fifth locally acquired case of the mosquito-borne illness dengue, this time in a resident of El Monte. The latest patient does not appear to have any connection with the four previous reported infections,

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.