Researchers from Arizona State University and Harvard University predict 6,800 possible new Ebola Virus Disease (EVD) cases in West Africa in the month of September if new control measures are not enacted, according to a study published PLoS Outbreaks this week.

Liberia Ebola  public service poster/CDC
Liberia Ebola public service poster/CDC

The study, “Temporal variations in the effective reproduction number of the 2014 West Africa Ebola outbreak,” is authored by Oscar Patterson-Lomba of the Harvard School of Public Health and Carlos Castillo-Chavez, Arizona State University Regent’s professor and MCMSC executive director and  Sherry Towers, research professor for the ASU Simon A. Levin Mathematical, Computational and Modelling Sciences Center (MCMSC) in the College of Liberal Arts and Sciences.

Through modelling analysis, researchers discovered that the rate of rise in cases significantly increased in August in Liberia and Guinea around the time that a mass quarantine was put in place.

Deteriorating living and hygiene conditions in some of the quarantined areas sparked riots last month. Sierra Leone began a three day country-wide quarantine today, where all citizens have been asked to stay at home, said Towers.

“There may be other reasons for the worsening of the outbreak spread, including the possibility that the virus has become more transmissible, but it’s also possible that the quarantine control efforts actually made the outbreak spread more quickly by crowding people together in unsanitary conditions,” Towers said.

Other issues have contributed to the spread including the lack of resources for effective quarantine and isolation in the under-developed countries that have been affected, and the high mobility of the population in a region with porous borders, according to the study.

Researchers examined the current outbreak data for Guinea, Sierra Leone and Liberia through statistical research methods up until Sept. 8, 2014, as estimated by the World Health Organization. The analysis examines the local rates of exponential rise to estimate how the reproduction number of cases appears to be changing over time. Calculations showed a range of 6,800 predicted new cases at the upper end of the spectrum and 4,400 on average if effective control measures are not put in place . For more infectious disease news and information, visit and “like” the Infectious Disease News Facebook page