The Alameda County Mosquito Abatement District announced Thursday via its Twitter account new cases of West Nile virus in the area.
Officials report a squirrel in Livermore and three crows in the Fremont/Newark area have tested positive for the virus.
Alameda County now has five birds and a squirrel that have tested positive for West Nile, the district said.
Officials reported earlier this month that a .
National figures reflect a 40 percent increase in West Nile virus cases since last week.
Those stats indicate the number of cases may rival the record years of 2002 and 2003, the Associated Press reported.