Predicting the extinction of Ebola spreading in Liberia due to mitigation strategies

The Ebola virus is spreading throughout West Africa and is causing thousands of deaths. In order to quantify the effectiveness of different strategies for controlling the spread, we develop a mathematical model in which the propagation of the Ebola virus through Liberia is caused by travel between counties. For the initial months in which the Ebola virus spreads, we find that the arrival times of the disease into the counties predicted by our model are compatible with World Health Organization data, but we also find that reducing mobility is insufficient to contain the epidemic because it delays the arrival of Ebola virus in each county by only a few weeks. We study the effect of a strategy in which safe burials are increased and effective hospitalisation instituted under two scenarios: (i) one implemented in mid-July 2014 and (ii) one in mid-August—which was the actual time that strong interventions began in Liberia. We find that if scenario (i) had been pursued the lifetime of the epidemic would have been three months shorter and the total number of infected individuals 80% less than in scenario (ii). Our projection under scenario (ii) is that the spreading will stop by mid-spring 2015.

[1]  J. Cox,et al.  Quantifying travel behavior for infectious disease research: a comparison of data from surveys and mobile phones , 2014, Scientific Reports.

[2]  Thomas Kenyon,et al.  Ebola 2014--new challenges, new global response and responsibility. , 2014, The New England journal of medicine.

[3]  Sergei Pond,et al.  Phylodynamic Analysis of Ebola Virus in the 2014 Sierra Leone Epidemic , 2014, PLoS currents.

[4]  Abdullah S Ali,et al.  The use of mobile phone data for the estimation of the travel patterns and imported Plasmodium falciparum rates among Zanzibar residents , 2009, Malaria Journal.

[5]  Albert-László Barabási,et al.  Understanding individual human mobility patterns , 2008, Nature.

[6]  Modeling the Impact of Interventions on an Epidemic of Ebola in Sierra Leone and Liberia , 2014, PLoS currents.

[7]  S. Dowell,et al.  Transmission of Ebola hemorrhagic fever: a study of risk factors in family members, Kikwit, Democratic Republic of the Congo, 1995. Commission de Lutte contre les Epidémies à Kikwit. , 1999, The Journal of infectious diseases.

[8]  Joel E. Cohen,et al.  Infectious Diseases of Humans: Dynamics and Control , 1992 .

[9]  J. Watmough,et al.  Reproduction numbers and sub-threshold endemic equilibria for compartmental models of disease transmission. , 2002, Mathematical biosciences.

[10]  Viroj Wiwanitkit,et al.  Ebola outbreak in west Africa. , 2014, African health sciences.

[11]  A. Tatem,et al.  Commentary: Containing the Ebola Outbreak - the Potential and Challenge of Mobile Network Data , 2014, PLoS currents.

[12]  Lidia A. Braunstein,et al.  Temporal Percolation of the Susceptible Network in an Epidemic Spreading , 2012, PloS one.

[13]  Alessandro Vespignani,et al.  influenza A(H1N1): a Monte Carlo likelihood analysis based on , 2009 .

[14]  M. Meltzer,et al.  Estimating the future number of cases in the Ebola epidemic--Liberia and Sierra Leone, 2014-2015. , 2014, MMWR supplements.

[15]  O Diekmann,et al.  The construction of next-generation matrices for compartmental epidemic models , 2010, Journal of The Royal Society Interface.

[16]  E. Volz.  SIR dynamics in random networks with heterogeneous connectivity , 2007, Journal of mathematical biology.

[17]  J. R. Scotti,et al.  Available From , 1973 .

[18]  J Bertolli,et al.  Clinical, virologic, and immunologic follow-up of convalescent Ebola hemorrhagic fever patients and their household contacts, Kikwit, Democratic Republic of the Congo. Commission de Lutte contre les Epidémies à Kikwit. , 1999, The Journal of infectious diseases.

[19]  Alessandro Vespignani,et al.  Invasion threshold in heterogeneous metapopulation networks. , 2007, Physical review letters.

[20]  M. Marathe,et al.  Modeling the Impact of Interventions on an Epidemic of Ebola in Sierra Leone and Liberia , 2014, PLoS currents.

[21]  Acknowledgements , 1992, Experimental Gerontology.

[22]  Alessandro Vespignani,et al.  Multiscale mobility networks and the spatial spreading of infectious diseases , 2009, Proceedings of the National Academy of Sciences.

[23]  Alessandro Vespignani,et al.  Dynamical Patterns of Epidemic Outbreaks in Complex Heterogeneous Networks , 1999 .

[24]  David R. Anderson,et al.  Model selection and multimodel inference : a practical information-theoretic approach , 2003 .

[25]  R. Colebunders,et al.  Epidemiologic and clinical aspects of the Ebola virus epidemic in Mosango, Democratic Republic of the Congo, 1995. , 1999, The Journal of infectious diseases.

[26]  Jonathan Dushoff,et al.  Modeling Post-death Transmission of Ebola: Challenges for Inference and Opportunities for Control , 2014, Scientific Reports.

[27]  A. Sanchez,et al.  The reemergence of Ebola hemorrhagic fever, Democratic Republic of the Congo, 1995. Commission de Lutte contre les Epidémies à Kikwit. , 1999, The Journal of infectious diseases.

[28]  Alessandro Vespignani,et al.  Assessing the International Spreading Risk Associated with the 2014 West African Ebola Outbreak , 2014, PLoS currents.

[29]  Gerardo Chowell,et al.  The Western Africa Ebola Virus Disease Epidemic Exhibits Both Global Exponential and Local Polynomial Growth Rates , 2014, PLoS currents.

[30]  P. Rollin,et al.  Ebola hemorrhagic fever in Kikwit, Democratic Republic of the Congo: clinical observations in 103 patients. , 1999, The Journal of infectious diseases.

[31]  Alessandro Vespignani,et al.  Spatiotemporal spread of the 2014 outbreak of Ebola virus disease in Liberia and the effectiveness of non-pharmaceutical interventions: a computational modelling analysis. , 2015, Lancet. Infectious Diseases (Print).

[32]  P. Kaye.  Infectious diseases of humans: Dynamics and control , 1993 .

[33]  Bernadette Saunders,et al.  The New Zealand Herald , 2014 .

[34]  A Flahault,et al.  Understanding the dynamics of Ebola epidemics , 2006, Epidemiology and Infection.

[35]  A Vespignani,et al.  Assessing the impact of travel restrictions on international spread of the 2014 West African Ebola epidemic. , 2014, Euro surveillance : bulletin Europeen sur les maladies transmissibles = European communicable disease bulletin.