Intensive animal production and backyard animal production are both causes of disease emergence and reemergence.

• A. True
• B. False
• C. Not related
• D. Both

Answer: (A)

High-density and close-contact farming create environments where pathogens can spread quickly, persist, and adapt, increasing the chances of emergence and reemergence. In intensive production, animals are kept in large numbers with frequent movement and uniform age, which can amplify transmission, stress responses, and pathogen shedding. This setup can also drive selective pressures—such as antimicrobial use and vaccination gaps—that promote resistance and evolution of pathogens, and it facilitates rapid spread within a herd or between farms and regions. Backyard production contributes through different but equally important routes: limited biosecurity, mixing of species, contact with wildlife, and close interaction with humans. These conditions allow pathogens to circulate locally, persist in reservoirs, and spill over to new hosts, including humans, and to reappear when immunity wanes or controls lapse. Since both systems can create opportunities for pathogens to spread, persist, and adapt, both are associated with disease emergence and reemergence.