The Alameda County Mosquito Abatement District announced Thursday via its Twitter account new cases of West Nile virus in the area.
Officials report that three crows in the Fremont/Newark area and a squirrel in Livermore 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.
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.
Alameda County officials reported earlier this month that a .