New Math Shows ?True Scale? of Ebola Outbreak

[nola_mnr]

http://www.theepochtimes.com/n3/1011663-new-math-shows-true-scale-of-ebola-outbreak/

From the data, the researchers [led by Tanja Stadler, professor of computational evolution at ETH Zurich] calculated a viral reproductive number of 2.18
[...]
Using the data made available to them, the ETH researchers were able to calculate an unreported case rate of 30 percent.
[...]
The researchers were also able to calculate the incubation period for Ebola—five days, although this value is subject to significant uncertainty—and the infectious time. Patients can pass on the virus from 1.2 to 7 days after becoming infected.
[...]

 

[Lizw]

Re: New Math Shows ?True Scale? of Ebola Outbreak

I'd sure like to see how they came up with the infectious time of 1.2 to 7 days. If that is true, then either the rate of new infection has been miscalculated, or other factors are slowing it down.

 

[Ronan Kelly]

Re: New Math Shows ?True Scale? of Ebola Outbreak

Insights into the Early Epidemic Spread of Ebola in Sierra Leone Provided by Viral Sequence Data
OCTOBER 6, 2014 ? RESEARCH
Print Article Citation PDF, XML
Email

AUTHORS
Tanja Stadler
Denise K?hnert
David A. Rasmussen
Louis du Plessis
ABSTRACT

Background and Methodology:
The current Ebola virus epidemic in West Africa has been spreading at least since December 2013. The first confirmed case of Ebola virus in Sierra Leone was identified on May 25. Based on viral genetic sequencing data from 72 individuals in Sierra Leone collected between the end of May and mid June, we utilize a range of phylodynamic methods to estimate the basic reproductive number (R0). We additionally estimate the expected lengths of the incubation and infectious periods of the virus. Finally, we use phylogenetic trees to examine the role played by population structure in the epidemic.

Results:
The median estimates of R0 based on sequencing data alone range between 1.65-2.18, with the most plausible model yielding a median R0 of 2.18 (95% HPD 1.24-3.55). Importantly, our results indicate that, at least until mid June, relief efforts in Sierra Leone were ineffective at lowering the effective reproductive number of the virus. We estimate the expected length of the infectious period to be 2.58 days (median; 95% HPD 1.24-6.98). The dataset appears to be too small in order to estimate the incubation period with high certainty (median expected incubation period 4.92 days; 95% HPD 2.11-23.20). While our estimates of the duration of infection tend to be smaller than previously reported, phylodynamic analyses support a previous estimate that 70% of cases were observed and included in the present dataset. The dataset is too small to show a particular population structure with high significance, however our preliminary analyses suggest that half the population is spreading the virus with an R0 well above 2, while the other half of the population is spreading with an R0 below 1.

Conclusions:
Overall we show that sequencing data can robustly infer key epidemiological parameters. Such estimates inform public health officials and help to coordinate effective public health efforts. Thus having more sequencing data available for the ongoing Ebola virus epidemic and at the start of new outbreaks will foster a quick understanding of the dynamics of the pathogen.
...
full paper at; http://currents.plos.org/outbreaks/...sierra-leone-provided-by-viral-sequence-data/