SACRAMENTO - Sacramento County and Placer County accounted for the bulk of the increase in human West Nile cases reported in the state.
The state's tally inched up a notch to 680 on Tuesday, up from 663 on Friday, with Sacramento County and Placer County each reporting five of the additional 17 cases.
Sacramento County, still leading the state in total numbers of cases, hit 155 cases Tuesday, and Placer County logged 30.
The rate of increase statewide has dropped steadily since Sept. 1.
Health officials caution, however, that mosquitoes still can transmit the virus and urge residents to take steps to prevent being bitten by a mosquito.