State health director Kenneth Kizer said he will issue prompt public alerts whenever Listeria monocytogenes bacteria are found in food products. State health officials were criticized for failing to make such a prompt announcement when the bacteria were found in Carl's Jr. milkshake mix last April. Listeriosis can be fatal, especially to infants and fetuses. The milkshake mix was produced at the Jerseymaid plant in Los Angeles and sold at more than 200 Carl's Jr. restaurants in Southern California and Arizona. State, federal and company officials decided not to issue a public alert, saying the mix already had been consumed, with no illnesses reported, by the time they learned laboratory tests for listeria were positive. No health alert is required if Listeria monocytogenes is found in food and no illness is reported.