Ebola "superspreaders," a small percentage of those infected by the disease in West Africa did the most damage by infecting others, according to a new study looking back at the 2014-15 epidemic.
The study, published this week in the journal Proceedings of the National Academy of Sciences, detailed research that determined that about three percent of the people infected by Ebola were responsible for about 61 percent of the infections, reported the Washington Post.
"We find that the epidemic was largely driven and sustained by superspreadings that are ubiquitous throughout the outbreak and that age is an important demographic predictor for superspreading," researchers said in the study.
"Our results highlight the importance of control measures targeted at potential superspreaders and enhance understanding of causes and consequences of superspreading for (the Ebola virus)."
The World Health Organization said 28,616 cases were reported in the West African countries of Guinea, Liberia, and Sierra Leone during the outbreak, leading to 11,310 deaths. Scientists believe that nearly two-third of those infected could have been prevented with proper controls on superspreaders, noted the Post.
Researchers from Princeton University and Oregon State University conducted a post-epidemic analysis of the timing and location of 200 community burials in urban areas around Freetown, Sierra Leone, said the Post.
They used a mathematical model to reconstruct the transmission network to identify the impact of so-called superspreaders.
"In the recent Ebola outbreak it's now clear that superspreaders were an important component in driving the epidemic," said Benjamin Dalziel, an assistant professor of population biology at Oregon State. "We now see the role of superspreaders as larger than initially suspected."
"There wasn't a lot of transmission once people reached hospitals and care centers. Because case counts during the epidemic relied heavily on hospital data, those hospitalized cases tended to be the cases we 'saw.' However, it was the cases you didn't see that really drove the epidemic, particularly people who died at home, without making it to a care center."
Now understanding the impact of superspreaders, researchers believe that messages tailored to individuals with higher risk and certain behaviors may have been more effective in slowing Ebola's spread than the once used that emphasized prevention and control.