SAN FRANCISCO (KGO) --California health officials are warning about a huge surge in the number of infections from West Nile virus. It's the worst they've ever seen.
Officials say the number of mosquitoes infected with the virus is at the highest level ever detected in the state.
That explains the dramatic increase in the number of human infections.
There have been 181 cases of West Nile reported so far this year, compared to 101 cases at the same time last year.
In the past week alone, 52 new cases have been reported.