Both children and adults can get listeriosis from eating food contaminated with the Listeria bacteria. Children with the condition are more likely to be diagnosed with meningitis (a more serious illness that is a complication of listeriosis) rather than listeriosis itself, while adults are more likely to have the infection affect different organs of the body. Otherwise, the condition is treated the same for both adults and children with a regimen of antibiotics.
Newborns that are infected with the Listeria bacteria at birth due to maternal infection are affected differently than either older children or adults. These cases have high fatality rates and must be treated immediately, usually with multiple antibiotics. Babies born with the infection and survive often experience neurological and developmental difficulties.