Any person can get sick from Cronobacter. Babies, older people, and people with weakened immune systems (for example, people being treated with immune-suppressing drugs for cancer, organ transplants, or other illnesses, or those with HIV infection or genetic conditions that affect the immune system) seem to get it more often. Meningitis from Cronobacter almost always happens in babies less than 2 months old. Almost all babies with Cronobacter have been fed powdered infant formula. Almost none have been fed only breast milk or liquid formula.