The United Nations’ interventions in the Sierra Leone Ebola outbreak led to a dramatic drop in the transmission of the disease, according to a study led by a University of Florida biostatistics researcher.
[Photo Credit: UN Photo/Martine Perret]
The study, published March 28 in the Proceedings of the National Academy of Sciences, marked the first time transmission dynamics of Ebola in Sierra Leone were evaluated at a fine scale, according to the researchers. They examined two categories of transmission: transmission within a household and transmission at a population level within a chiefdom, an administrative unit akin to a county in the United States.
When the United Nations intervened in Sierra Leone to slow the Ebola outbreak in October 2014, the country saw a 43 percent reduction in the transmission at the population level. When the intervention was completely in place by the end of December 2014, the rate dropped by 65 percent at the population level and 82 percent within households, according to one of the study’s first authors, Dr. Yang Yang, an assistant professor in the department of biostatistics in the UF College of Public Health and Health Professions and the UF College of Medicine.
“That was quite an effective drop,” said Dr. Yang, who is also a member of the UF Emerging Pathogens Institute. “For the household level, that number at 82 percent was even more dramatic.”
Dr. Yang said the paper’s findings underscore the need for early intervention in disease outbreaks.
“Particularly interesting to me is that interventions in the early stages of outbreak were so important,” Dr. Yang said. “The game really changed when the U.N. initiated these intervention programs, even before the programs ran at their full capacity.”
In particular, isolating and identifying cases of Ebola and increasing the number of treatment centers were key — but could still use help.
“That alone in the future may be effective against other outbreaks, but it could be much more effective in combination with more advanced prevention strategies,” Dr. Yang said, referring to a strategy of vaccination called “ring vaccination.”
The researchers also called for more robust survey methods during an outbreak, which could help them study how to better keep future outbreaks of infectious diseases in check.
“Information like the number of people in a household, along with their age and gender, is very important, and collecting that information is essentially a few more survey questions,” Dr. Yang said. “Having this type of data collection for future outbreaks of newly emerging and re-emerging diseases would be very helpful.”