El Dorado County’s public health officer says a single case of the plague in a South Lake Tahoe resident isn’t cause for alarm. Nancy Williams tells News 4 the disease is very rare. The person is believed to have contracted it from an infected flea while walking a dog. Williams says infected fleas usually feed on rodents and squirrels–not humans or dogs. The victim is expected to make a full recovery. El Dorado County’s last case of plague was five years ago.