An instructor is reviewing Salmonella infections with her class. Which of the following comments indicates that the student needs further review on Salmonella?

"Salmonella is a bacterial infection."

"Salmonella symptoms include headaches, abdominal pain, diarrhea, nausea, vomiting, and fever."

"Salmonella may be spread by spores that form once contaminated blood is exposed to the air."

"Salmonella has a 48-hour incubation period."