Microbiology
Production of toxin-mediated symptoms from an internal colonization that are then excreted through urine only after systemic infection develops.
Continuous shedding of organisms in respiratory droplets due to active lower respiratory infection with high pathogen load.
Mechanical transfer of organisms on hands, clothing, or instruments without colonization of the carrier.
Formation of persistent intracellular latent infection that reactivates later and spreads systemically by viremia in asymptomatic carriers.