A new ‘real-time’ strategy for future Foot and Mouth outbreaks states that focusing on surveillance and vaccination is the most effective method to quickly fight the spread of the disease.
Dr. William Probert and Dr. Michael Tildesley in Warwick’s School of Life Sciences and Mathematics Institute have developed a disease control model based on data from previous outbreaks.
According to a report produced by the academics, “focusing on surveillance and vaccination will allow us to fight a disease outbreak even when we know very little about it”.
First weeks of a Foot and Mouth epidemic
Determining the optimal strategy to control Foot and Mouth can be challenging in the first weeks of an epidemic, due to uncertainty about the nature of the outbreak and how the disease will be spread.
The researchers sought to resolve this uncertainty, enabling the spread of the disease to be controlled more rapidly and effectively than in the past.
Using data from previous Foot and Mouth outbreaks – the UK in 2001 and Japan in 2010 – they simulated the spread of disease, and at each stage of the outbreak analysed the real-time efficacy of multiple different approaches.
These methods included:
- Culling only infected farms;
- Culling infected farms, plus farms designated as ‘dangerous contact’;
- Culling infected farms, dangerous contact farms and neighbouring farms (contiguous culling);
- Ring culling at three kilometres, and at 10km;
- Vaccination at three kilometres, and at 10km.
At every stage in an outbreak, locally targeted approaches – the culling of infected premises and ring vaccination around confirmed infected farms – were always found to be the most effective.
According to the researchers, ring culling was never an effective method.
Removing the uncertainty
There is spatial uncertainty in the early stages of an epidemic. The report states that targeted surveillance is “crucial” to allow authorities to gain information and resolve this uncertainty as quickly as possible.
Removing the uncertainty factor will ultimately put a control on the spread of the disease earlier in an outbreak.
According to the research article composed by the academics:
“Most mathematical models developed for disease control look back to previous outbreaks and make their calculations using all the information from the whole episode.
“This new strategy is rare in that it works out the best approach with only the information to hand in the middle of an outbreak.
Dr. Michael Tildesley, associate professor in the University of Warwick’s School of Life Sciences and Mathematics Institute, said:
This work highlights both the limitations and the benefits of using an infectious disease model in real time, during an ongoing outbreak.
“It is crucial for policymakers to employ surveillance to resolve uncertainty in how the disease is spreading as rapidly as possible, as this may have significant implications upon our ability to predict future epidemic behaviour.”
