Abstract
Commercial livestock movements are an important factor in the spread of infectious diseases of livestock such as African swine fever (ASF). The analysis of these movements can provide valuable intelligence for emergency preparedness: network analysis can determine a movement network’s effectiveness at transmitting infection and the relative importance of different holdings and connections, and incorporating detailed movement data into transmission models can improve the accuracy of predictions such as outbreak size. However, the effective use of livestock movement data is fraught with challenges. On the data side, commercial sensitivity concerns can inhibit data sharing between relevant actors. On the analysis side, network and modelling studies require resources, time and expertise that may be in short supply. We have developed Movenet, a toolkit that addresses these challenges and simplifies the effective use of livestock movement data in veterinary public health.
Movenet is an R package that facilitates the use of livestock movement data in two ways:
- To improve the potential for collaborative data sharing by addressing commercial sensitivity concerns, Movenet provides data owners and data managers with a variety of options to make livestock movement data less identifiable: holding identifiers can be substituted (pseudonymised); holding geographical coordinates can be jittered in a density-dependent manner; and movement dates and weights can be modified by addition of random noise or by rounding. Modified datasets can be viewed and downloaded in various formats. The authors encourage users to consider that data modifications may impact the results of any analyses, and to seek an appropriate balance between identifiability of data and accuracy of results. To this end, Movenet provides users with the opportunity to compare the effects of various data modifications on network measures and model predictions.
- To facilitate the effective use of (real or modified) movement networks in risk assessment, Movenet provides researchers and decision-makers with a quick entry into social network analysis of livestock movement data. Movenet produces a standardised, downloadable report, with a range of tables and figures displaying metrics relevant to disease spread. The report includes basic network properties such as the number of active holdings and edges (overall and over time), static network analysis of (monthly or yearly) snapshots, temporal analysis including ingoing and outgoing contact chains (reachability), and component analysis. A basic guide to interpretation is also provided. An equivalent quick entry into transmission modelling using livestock movement data is currently in development.
Movenet is freely downloadable, open-source software (https://github.com/digivet-consortium/movenet). An accompanying interactive app is also available, which makes the package functions accessible to users who are not confident in R, or who prefer graphical user interfaces.