The Lancet Infectious Diseases
Dec 2014 Volume 14 Number 12 p1163 – 1292
http://www.thelancet.com/journals/laninf/issue/current

Editorial
Rationality and coordination for Ebola outbreak in west Africa
The Lancet Infectious Diseases
According to WHO, as of Oct 31, 2014, 13 540 people have been diagnosed with Ebola virus disease in eight countries—including 4951 deaths. Transmission remains persistent and widespread in Guinea (1667 cases, 1018 deaths), Liberia (6535 cases, 2413 deaths), and Sierra Leone (5338 cases, 1510 deaths). Dedicated doctors, nurses, and other health-care workers have made great efforts to contain the epidemic. WHO reports that 450 of these health-care workers have developed the disease and more than 230 have died. WHO has attributed these cases to the shortage and improper use of personal protective equipment, and lack of trained medical personnel.

Health-care workers returning from west Africa, who have put their lives at risk to help others, have been quarantined in several US states, such as New York and New Jersey; more recently, Illinois has started imposing the same measures. Quarantine measures in the USA were put in place after Craig Spencer returned from Guinea and travelled around New York City before he fell ill. A further development was the decision by Louisiana health officials to ban anyone who travelled from Ebola-affected parts of west Africa, and hence Ebola researchers were told not to come to the American Society of Tropical Medicine and Hygiene meeting held recently in New Orleans…

Article
Dynamics and control of Ebola virus transmission in Montserrado, Liberia: a mathematical modelling analysis
Joseph A Lewnard BA a b †, Martial L Ndeffo Mbah PhD a b †, Jorge A Alfaro-Murillo PhD a b, Prof Frederick L Altice MD a c, Luke Bawo MPH d, Tolbert G Nyenswah MPH d, Prof Alison P Galvani PhD a b
Summary
Background
A substantial scale-up in public health response is needed to control the unprecedented Ebola virus disease (EVD) epidemic in west Africa. Current international commitments seek to expand intervention capacity in three areas: new EVD treatment centres, case ascertainment through contact tracing, and household protective kit allocation. We aimed to assess how these interventions could be applied individually and in combination to avert future EVD cases and deaths.
Methods
We developed a transmission model of Ebola virus that we fitted to reported EVD cases and deaths in Montserrado County, Liberia. We used this model to assess the effectiveness of expanding EVD treatment centres, increasing case ascertainment, and allocating protective kits for controlling the outbreak in Montserrado. We varied the efficacy of protective kits from 10% to 50%. We compared intervention initiation on Oct 15, 2014, Oct 31, 2014, and Nov 15, 2014. The status quo intervention was defined in terms of case ascertainment and capacity of EVD treatment centres on Sept 23, 2014, and all behaviour and contact patterns relevant to transmission as they were occurring at that time. The primary outcome measure was the expected number of cases averted by Dec 15, 2014.
Findings
We estimated the basic reproductive number for EVD in Montserrado to be 2•49 (95% CI 2•38—2•60). We expect that allocating 4800 additional beds at EVD treatment centres and increasing case ascertainment five-fold in November, 2014, can avert 77 312 (95% CI 68 400—85 870) cases of EVD relative to the status quo by Dec 15, 2014. Complementing these measures with protective kit allocation raises the expectation as high as 97 940 (90 096—105 606) EVD cases. If deployed by Oct 15, 2014, equivalent interventions would have been expected to avert 137 432 (129 736—145 874) cases of EVD. If delayed to Nov 15, 2014, we expect the interventions will at best avert 53 957 (46 963—60 490) EVD cases.
Interpretation
The number of beds at EVD treatment centres needed to effectively control EVD in Montserrado substantially exceeds the 1700 pledged by the USA to west Africa. Accelerated case ascertainment is needed to maximise effectiveness of expanding the capacity of EVD treatment centres. Distributing protective kits can further augment prevention of EVD, but it is not an adequate stand-alone measure for controlling the outbreak. Our findings highlight the rapidly closing window of opportunity for controlling the outbreak and averting a catastrophic toll of EVD cases and deaths.
Funding
US National Institutes of Health.