mechanisms of cross-species transmission: viral adaptation, host receptors, and immune evasion

cross-species transmission zoonosis spillover pathogen virus bacteria fungi prion adaptation mutation recombination evolution susceptibility host reservoir tropism shedding virulence exposure infection immune resistance surveillance epidemiology outbreak pandemic spillback wildlife livestock human vector zoonotic genetic reassortment ecology fitness emergence antigenic receptor host-switching phylogeny interspecies epizootic enzootic morbidity mortality