Listeria at a glance

Health investigators are racing to identify the brands of caramel apples suspected of being tainted with Listeria monocytogenes and causing a deadly outbreak of listeriosis.

Cases: 29

Deaths: 5*

Hospitalizations: 29

Number of states involved: 10

Cases in California: 1

Recall: 1; Happy Valley brand caramel apples

Symptoms of listeriosis: High fever, headaches, neck stiffness, nausea and diarrhea

At greatest risk: Infants, the elderly, people with weakened immune systems, pregnant women.

Only three deaths have been confirmed as being caused by listeria.

Sources: U.S. Centers for Disease Control and Prevention; California Department of Public Health