IMPERIAL COUNTY â Two local mosquito pools have tested positive for St. Louis encephalitis, the Imperial County Public Health Department announced Friday. One of the mosquito pools was collected in El Centro near West Main Road just east of Austin Road. The other was in Imperial near the area of La Paz Drive and Puerto Vallarta Avenue. The samples were collected on Tuesday and results were received Friday. â As temperatures increase, so do mosquito populations and disease risk, which poses a serious public health threat in our communities,â said Imperial County Health Officer D...