It seems that the answer is yes. There do seem to be superspreaders, a loosely defined term for people who infect a disproportionate number of others, whether as a consequence of genetics, social habits or simply being in the wrong place at the wrong time.

But those virus carriers at the heart of what are being called superspreading events can drive and have driven epidemics, researchers say, making it crucial to figure out ways to identify spreading events or to prevent situations, like crowded rooms, where superspreading can occur.

Just as important are those at the other end of the spectrum — people who are infected but unlikely to spread the infection.

Distinguishing between those who are more infectious and those less infectious could make an enormous difference in the ease and speed with which an outbreak is contained, said Jonathan Zelner, a statistician at the University of Michigan. If the infected person is a superspreader, contact tracing is especially important. But if the infected person is the opposite of a superspreader, someone who for whatever reason does not transmit the virus, contact tracing can be a wasted effort.