Sales of mosquito repellant have increased in the San Gabriel Valley due to threat of West Nile Virus. The California Department of Health Services recommends applying insect repellant with Diethyl-m-toluamine (DEET).
Officials estimate the infection rate of West Nile Virus is higher than what is currently known since health officials stopped testing dead birds where the virus is confirmed to be present. Arcadia and West Covina had high rates of infection among San Gabriel Valley communities.