Final answer:
Nathan Wolfe's TED talk emphasizes the importance of studying viruses at the zoonotic stage, where they transfer from animals to humans, to prevent and control outbreaks.
Step-by-step explanation:
In the Jungle search for Viruses TED talk by Nathan Wolfe, the focus is suggested to be on the study of viruses at the stage where they are transferred from animals to humans, which is the zoonotic stage. This stage is critical because it represents the point at which a virus can potentially begin to infect and spread among humans, causing zoonotic diseases. Understanding and monitoring this stage of virus transmission can help prevent widespread viral outbreaks, like the case of the H5N1 avian flu virus, and ensure better control of such diseases.