Transmission of the Ebola virus occurs in social clusters, a finding that has ramifications for case reporting and public health, according to authors of a new study published today in the journal Clinical Infectious Diseases.

Among the 11 co-authors are SFI Omidyar Fellow Sam Scarpino (a first author) and SFI External Professor Lauren Ancel Meyers.

Prior studies of Ebola transmission were based on models that assumed the spread of infection occurred between random pairs of individuals. However, because transmission of the virus happens most often in hospitals, households, and funeral settings, the international team of researchers investigated the possibility of clustered transmission, or spread between individuals in small social groups.

"Clustered transmission means that when you have an individual who has the disease and they transmit it to another individual, the next transmission is likely to be to someone who the first individual knew," says Jeffrey Townsend, an associate professor of biostatistics and ecology & evolutionary biology at Yale. "It's all happening within little small social networks."

These findings underscore the importance of rapid contact tracing and quarantine of symptomatic individuals, which can be highly effective among these clustered groups. The analysis also points to the need for more public health resources, such as hospital beds, to make sure every infected individual in West Africa is quickly isolated and receives professional care.

"It is essential for this type of integrative work to be part of future outbreak responses," Scarpino says. 

Read the Yale University news release (December 16, 2014)

Read the study in Clinical Infectious Diseases (December 16, 2014)

Read the article in The New York Times (December 16, 2014)