title: Ebola virus disease outbreak in Nigeria: Transmission dynamics and rapid control.
abstract: International air travel has already spread Ebola virus disease (EVD) to major cities as part of the unprecedented epidemic that started in Guinea in December 2013. An infected airline passenger arrived in Nigeria on July 20, 2014 and caused an outbreak in Lagos and then Port Harcourt. After a total of 20 reported cases, including 8 deaths, Nigeria was declared EVD free on October 20, 2014. We quantified the impact of early control measures in preventing further spread of EVD in Nigeria and calculated the risk that a single undetected case will cause a new outbreak. We fitted an EVD transmission model to data from the outbreak in Nigeria and estimated the reproduction number of the index case at 9.0 (95% confidence interval [CI]: 5.2-15.6). We also found that the net reproduction number fell below unity 15 days (95% CI: 11-21 days) after the arrival of the index case. Hence, our study illustrates the time window for successful containment of EVD outbreaks caused by infected air travelers.
authors.affiliation: Institute of Social and Preventive Medicine (ISPM), University of Bern, Bern, Switzerland. Electronic address: christian.althaus@alumni.ethz.ch.
authors.forename: C L
authors.initials: CL
authors.lastname: Althaus
authors.affiliation: Institute of Social and Preventive Medicine (ISPM), University of Bern, Bern, Switzerland.
authors.forename: N
authors.initials: N
authors.lastname: Low
authors.affiliation: World Health Organization - Nigeria Office, Federal Republic of Nigeria.
authors.forename: E O
authors.initials: EO
authors.lastname: Musa
authors.affiliation: Federal Ministry of Health, Federal Republic of Nigeria.
authors.forename: F
authors.initials: F
authors.lastname: Shuaib
authors.affiliation: Institute of Social and Preventive Medicine (ISPM), University of Bern, Bern, Switzerland.
authors.forename: S
authors.initials: S
authors.lastname: Gsteiger
mesh_terms: D004196:Disease Outbreaks / Q000706:statistics & numerical data*; D019142:Hemorrhagic Fever, Ebola / Q000453:epidemiology*; D006801:Humans; D008962:Models, Theoretical; D009549:Nigeria / Q000453:epidemiology
keywords: Basic reproduction number; Ebola virus disease; Mathematical model; Nigeria; Outbreak