Temporal Changes in Ebola Transmission in Sierra Leone and Implications for Control Requirements: a Real-time Modelling Study

In this study we used a mathematical model of Ebola virus transmission to estimate how the reproduction number, R, defined as the average number of secondary cases generated by a typical infectious host, varied between August 2014 and January 2015 in the nine districts of Sierra Leone with the most active transmission. As a large number of additional ETC and EHC beds were introduced in Sierra Leone in December 20143, we also used the model to estimate how many cases would be present in the community by the end of March 2015, and evaluate whether beds currently in place will be sufficient to meet demand. Methods We used a combination of patient and situation report data to obtain reliable and up-to-date time series of the number of confirmed and probable cases. The WHO publishes the weekly number of confirmed and probable cases at the subnational level for Sierra Leone on their website4. These data come from the patient database, which is the most reliable data source because it is continuously cleaned. In particular, it takes into account reclassification and avoids double counting of cases. However, the patient database is updated with substantial delay so that the number of reported cases is typically underestimated in the most recent weeks. To tackle this issue, we compiled case data from the daily situation reports issued by the Sierra Leone Ministry of Health and Sanitation (MoHS SitReps) between 10th August 2014 and 18th January 20151. The WHO patient database was use...
Source: PLOS Currents Outbreaks - Category: Epidemiology Authors: Source Type: research