Which age group of animals often has higher prevalence of Salmonella?

• A. Adult
• B. Young
• C. Old
• D. Neonatal

Answer: (B)

The main concept here is that age affects both susceptibility to infection and exposure patterns, which together influence how common Salmonella is in a group. Salmonella tends to persist in the gut and be shed in feces, and animals with immature or developing immune systems, disrupted gut flora, or stressed, crowded conditions are more likely to become infected and shed for longer periods.

During the juvenile period, immune defenses are still maturing and maternal antibodies have waned, while exposure often increases due to weaning, diet changes, and housing with other animals. This combination makes young animals more vulnerable to infection and more likely to contribute to transmission, raising the observed prevalence in this age group. In contrast, adults usually have stronger, more established immunity and stable gut ecosystems, reducing infection and shedding. Neonates can be protected early by maternal antibodies, and while they can be affected, the highest and most detectable prevalence often occurs in the younger, post-neonatal period when exposure and susceptibility align.