Scientists are learning more about superspreaders, people who transmit infections to a much greater than expected number of new hosts, including that they may be the driving force behind pandemics.
During the 2003 SARS pandemic, researchers found that the superspreaders were instrumental in spreading the global outbreak. During the pandemic, 8,098 people were infected and 774 people were killed. In one instance, a doctor from Hong Kong indirectly infected 257 people with SARS, Slate reports.
“SARS made the superspreader phenomenon so obvious we could no longer ignore it,” James Lloyd-Smith, an infectious disease expert at UCLA, said, according to Slate. “(But) SARS is just one point along a continuum—all infections show this (pattern) to some degree.”
Researchers found that approximately 20 percent of the population is responsible for 80 percent of the diseases spread. Finding the small portion of the population that drives most of the transmissions can help doctors to understand and prevent outbreaks.
“If you just apply infectious disease control measures randomly, you may not be able to actually eliminate an infectious disease,” Dana Hawley, a Virginia Tech disease ecologist, said, according to Slate. “But if you target the most relevant 20 percent, then you can vaccinate or treat enough of these individuals to eliminate the disease much more quickly.”
Scientists are also looking at people who do not transmit infections to anyone else to determine how their behavior and immune systems differ from superspreaders.