Seoul virus tends to be more common in which rats?

• A. Female wild rats
• B. Male wild rats
• C. Domestic pet rats
• D. Juvenile rats

Answer: (B)

Seoul virus prevalence in rat populations is influenced by sex-related behavior, with male rats in the wild showing higher infection rates. This is because males tend to roam more, disperse during breeding, and engage in more aggressive interactions. Those behaviors increase their exposure to contaminated urine, feces, and saliva and raise the chances of encountering other infected rats, which facilitates transmission. Females typically stay closer to the nest and have fewer aggressive encounters, leading to lower exposure. Juveniles have had less time and opportunity to encounter infected rats, so infection rates tend to be lower than in adults. In domestic pet rats, infection is less common due to controlled environments, but the question focuses on wild rats, where the sex-related exposure pattern makes males the most likely to be infected.