Comments on: Modeling the Impact of Interventions on an Epidemic of Ebola in Sierra Leone and Liberia http://currents.plos.org/outbreaks/article/modeling-the-impact-of-interventions-on-an-epidemic-of-ebola-in-sierra-leone-and-liberia/ Sat, 27 Oct 2018 04:18:43 +0000 hourly 1 https://wordpress.org/?v=4.5.3 By: Christian L. Althaus http://currents.plos.org/outbreaks/article/modeling-the-impact-of-interventions-on-an-epidemic-of-ebola-in-sierra-leone-and-liberia/#comment-1468 Wed, 12 Nov 2014 11:53:57 +0000 http://currents.plos.org/outbreaks/?post_type=article&p=48250#comment-1468 Thanks for clarifying some of our concerns in this update of the manuscript. However, I still think that there are some inconsistencies in your model.

After consulting the study by Legrand et al. and your paper again, I agree that the weighting of the transition rates is consistent and correct. The difference is that the study by Legrand defines a case fatality ratio delta that is then used to compute the scaling factors delta_1 and delta_2. In your manuscript, you call delta_1 and delta_2 case fatality rate and this might not be correct. From the ordinary differential equations, one can directly calculate the case fatality rate for the hospitalized as gamma_DH*delta_2/(gamma_DH*delta_2 + gamma_IH*(1-delta_2)). For the parameters from Sierra Leone, that would be 88% and not 75%.

If you model your system as shown in Figure 2 of the Appendix, delta_2 indeed corresponds to the case fatality rate in hospitals. In this case, you should change your ordinary differential equations to match the model scheme in Figure 2 of the Appendix.

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By: PLOS Currents http://currents.plos.org/outbreaks/article/modeling-the-impact-of-interventions-on-an-epidemic-of-ebola-in-sierra-leone-and-liberia/#comment-1412 Thu, 06 Nov 2014 22:14:47 +0000 http://currents.plos.org/outbreaks/?post_type=article&p=48250#comment-1412 The authors updated this article in response to readers comments on the previous edition. The changes made are:
– Changed one symbol (iota) to theta_1 in order to be more consistent with Legrand et al and slightly changed the wording of this parameter’s meaning.
– Corrected a typo in the compartmental flow diagram.