[Population Modeling] Contribution for this year's paper population modeling by examples

[Aristides Moustakas]

Dear all,

I wish to contribute some text for the paper population modeling by examples
for this year

I am mentioning 2 papers, the one is a modelling paper (coupling agent
based models) and the second one is a statistical time series analysis of
public health data that confirms the major finding of the modelling paper.
I thought the two of them tie well together as in fact the predictions from
the modelling paper preceded the statistical analysis of public data.
The second paper - the one performing statistical analysis - has an
interest also on its own as it shows that more frequent testing leads to
disease control, but apart from that 40 MPs have submitted a freedom of
information act in the British Parliament (the House of Commons), as it
turned out that there existed longer term data than the ones that were
available when when published the paper, and these data were made publicly
available following up the publication of our second paper.

As I am merging two papers the text may be too long. If that is the case
please let me know and I will try to make it shorter.

Best regards,

Aris



Bovine tuberculosis (TB) is a chronic disease in cattle that causes a
serious food security challenge to the agricultural industry in terms of
dairy and meat production. In several countries badgers are a recognised
reservoir of infection and there has been substantial discussion about
potential control strategies. We present a coupling of agent based models
of bovine TB in badgers and cattle, which aims to capture the key details
of the natural history of the disease and of both species with a
scale-specific model calibration. The model is spatially explicit it
follows a very large number of cattle and badgers (big data) on a different
grid size for each species and includes also winter housing. We perform
model validation and confront model outputs with reported patterns of both
cattle and badger populations. Parameter space used as input in simulations
was swept out using Latin hypercube sampling and sensitivity analysis to
model outputs was conducted using mixed effect models. By exploring a large
and computationally intensive parameter space we show that of the available
control strategies it is the frequency of TB testing and whether or not
winter housing is practised that have the most significant effects on the
number of infected cattle. Badger culling explained about 5% of the
variance in the number of infected cattle.

Following up from the modelling work, time series statistical analysis of
public data regarding TB incidence and prevalence in different regions in
GB was performed. After detecting trends over time, underlying regional
differences were compared with the testing policies in the region. Different
regions in GB have different cattle testing policies: Scotland has had a
risk based surveillance testing policy under which high risk herds are
tested frequently, and in 2009 was officially declared as TB free. Wales
have had an annual or more frequent testing policy for all cattle herds
since January 2010, while in England several herds are still tested every
four years except some high TB prevalence areas where annual testing is
applied. Total cattle slaughtered were positively correlated with total
tests in the West, North, and East English regions, with high slopes of
regression indicating that additional testing is likely to facilitate the
eradication of the disease. There was no correlation between total cattle
slaughtered and total tests on herds in Wales indicating that herds are
tested frequent enough in order to detect all likely cases and so control
TB. The main conclusion of the analysis conducted here is that more
frequent testing is leading to lower TB infections in cattle both in terms
of TB prevalence as well as TB incidence.

References:

Moustakas, A., Evans, M., 2015. Coupling models of cattle and farms with
models of badgers for predicting the dynamics of bovine tuberculosis (TB).
Stoch Environ Res Risk Assess 29, 623-635.

Moustakas, A., Evans, M.R., 2016. Regional and temporal characteristics of
bovine tuberculosis of cattle in Great Britain. Stoch Environ Res Risk
Assess 30, 989-1003.
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