Limits...
Potential for large outbreaks of Ebola virus disease.

Camacho A, Kucharski AJ, Funk S, Breman J, Piot P, Edmunds WJ - Epidemics (2014)

Bottom Line: The largest outbreak of Ebola to date is currently underway in West Africa, with 3944 cases reported as of 5th September 2014.Our analysis suggests that the person-to-person reproduction number was 1.34 (95% CI: 0.92-2.11) in the early part of the outbreak.Using stochastic simulations we demonstrate that the same epidemiological conditions that were present in 1976 could have generated a large outbreak purely by chance.

View Article: PubMed Central - PubMed

Affiliation: Centre for the Mathematical Modelling of Infectious Diseases, Department of Infectious Disease Epidemiology, London School of Hygiene and Tropical Medicine, London, United Kingdom. Electronic address: anton.camacho@lshtm.ac.uk.

Show MeSH

Related in: MedlinePlus

Distribution of Ebola outbreak sizes in different scenarios. (A) Outbreak size distribution from 10,000 stochastic simulations using the maximum a posteriori probability estimate. (B) Distribution of number of cases reported in Ebola outbreaks in Africa from 1976 to present. (C) Outbreak size distribution from 10,000 stochastic simulations when hospital is closed 7 days after the date of the first onset (i.e. 1st September). All other parameters remain the same. (D) Outbreak size distribution from 10,000 stochastic simulations when person-to-person transmission is reduced by 50% rather than 98%. The final category includes all outbreaks with more than 2500 cases.
© Copyright Policy - CC BY-NC-ND
Related In: Results  -  Collection

License
getmorefigures.php?uid=PMC4255970&req=5

fig0030: Distribution of Ebola outbreak sizes in different scenarios. (A) Outbreak size distribution from 10,000 stochastic simulations using the maximum a posteriori probability estimate. (B) Distribution of number of cases reported in Ebola outbreaks in Africa from 1976 to present. (C) Outbreak size distribution from 10,000 stochastic simulations when hospital is closed 7 days after the date of the first onset (i.e. 1st September). All other parameters remain the same. (D) Outbreak size distribution from 10,000 stochastic simulations when person-to-person transmission is reduced by 50% rather than 98%. The final category includes all outbreaks with more than 2500 cases.

Mentions: To examine the possible range of dynamics for an outbreak with the same characteristics as the one observed in the 1976 Yambuku outbreak, we ran 10,000 stochastic simulations of our model under the maximum a posteriori probability estimates of the parameters (Fig. 5). We found that although most simulated epidemics were of similar size to the one in 1976, major outbreaks could also occur. Although only 3% of simulations resulted in a major outbreak (i.e. more than 1000 cases), the cumulated number of cases could reach up to several thousands in the worst-case scenario (Fig. 6A). In the context of the 1976 epidemic, such a major outbreak could have arisen if – by chance – a sufficiently high number of infections had occurred before the change of community contact and hospital seeking behaviours.


Potential for large outbreaks of Ebola virus disease.

Camacho A, Kucharski AJ, Funk S, Breman J, Piot P, Edmunds WJ - Epidemics (2014)

Distribution of Ebola outbreak sizes in different scenarios. (A) Outbreak size distribution from 10,000 stochastic simulations using the maximum a posteriori probability estimate. (B) Distribution of number of cases reported in Ebola outbreaks in Africa from 1976 to present. (C) Outbreak size distribution from 10,000 stochastic simulations when hospital is closed 7 days after the date of the first onset (i.e. 1st September). All other parameters remain the same. (D) Outbreak size distribution from 10,000 stochastic simulations when person-to-person transmission is reduced by 50% rather than 98%. The final category includes all outbreaks with more than 2500 cases.
© Copyright Policy - CC BY-NC-ND
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC4255970&req=5

fig0030: Distribution of Ebola outbreak sizes in different scenarios. (A) Outbreak size distribution from 10,000 stochastic simulations using the maximum a posteriori probability estimate. (B) Distribution of number of cases reported in Ebola outbreaks in Africa from 1976 to present. (C) Outbreak size distribution from 10,000 stochastic simulations when hospital is closed 7 days after the date of the first onset (i.e. 1st September). All other parameters remain the same. (D) Outbreak size distribution from 10,000 stochastic simulations when person-to-person transmission is reduced by 50% rather than 98%. The final category includes all outbreaks with more than 2500 cases.
Mentions: To examine the possible range of dynamics for an outbreak with the same characteristics as the one observed in the 1976 Yambuku outbreak, we ran 10,000 stochastic simulations of our model under the maximum a posteriori probability estimates of the parameters (Fig. 5). We found that although most simulated epidemics were of similar size to the one in 1976, major outbreaks could also occur. Although only 3% of simulations resulted in a major outbreak (i.e. more than 1000 cases), the cumulated number of cases could reach up to several thousands in the worst-case scenario (Fig. 6A). In the context of the 1976 epidemic, such a major outbreak could have arisen if – by chance – a sufficiently high number of infections had occurred before the change of community contact and hospital seeking behaviours.

Bottom Line: The largest outbreak of Ebola to date is currently underway in West Africa, with 3944 cases reported as of 5th September 2014.Our analysis suggests that the person-to-person reproduction number was 1.34 (95% CI: 0.92-2.11) in the early part of the outbreak.Using stochastic simulations we demonstrate that the same epidemiological conditions that were present in 1976 could have generated a large outbreak purely by chance.

View Article: PubMed Central - PubMed

Affiliation: Centre for the Mathematical Modelling of Infectious Diseases, Department of Infectious Disease Epidemiology, London School of Hygiene and Tropical Medicine, London, United Kingdom. Electronic address: anton.camacho@lshtm.ac.uk.

Show MeSH
Related in: MedlinePlus