Wikipedia
A super-spreader is a host—an organism infected with a disease—that infects disproportionally more secondary contacts than other hosts also infected with the same disease. A sick human can be a super-spreader; they would be more likely to infect others than most people with the disease. Super-spreaders are thus of high concern in epidemiology, the study of the spread of diseases.
Some cases of super-spreading conform to the 20/80 rule, where approximately 20% of infected individuals are responsible for 80% of transmissions, although super-spreading can still be said to occur when super-spreaders account for a higher or lower percentage of transmissions. In epidemics with super-spreading, the majority of individuals infect relatively few secondary contacts.
Super-spreading events are shaped by multiple factors including a decline in herd immunity, nosocomial infections, virulence, viral load, misdiagnosis, airflow dynamics, immune suppression, and co-infection with another pathogen.