Investigating Transboundary Spread Patterns and Cluster Characteristics of Lumpy Skin Disease (LSD) Outbreaks in...

Lumpy skin disease (LSD) has rapidly spread across Asia, posing significant threats to livestock industries. This study aims to examine the spatial directional trends and spatiotemporal clusters of LSD outbreaks in South, East, and Southeast Asia from January 2019 to December 2023. Official LSD outbreak data were analyzed using spatial and spatiotemporal models. The standard deviational ellipse (SDE) method was applied to assess directional distribution trends, while space-time permutation (STP) and space-time Poisson models were utilized to identify outbreak clusters. A total of 1385 LSD outbreaks were recorded in the study region during the period. In the Asia region, the directional analysis of all outbreaks revealed trends from the south to the southeast and from the northeast to the southeast, based on the SDE case-weighted and SDE case-unweighted approaches, respectively. Additionally, distinct directional patterns were identified for each subregion. A comparison of the space-time Poisson and STP models showed variations in cluster locations and sizes. The STP model identified primary clusters in India, Bhutan, the Republic of Korea, and Vietnam, whereas the space-time Poisson model highlighted primary clusters in India, Thailand, and Mongolia. Both models detected secondary clusters in various countries including India, Pakistan, Bhutan, China, Mongolia, Nepal, Cambodia, Vietnam, Thailand, Indonesia, Malaysia, Singapore, Sri Lanka, and the Republic of Korea, with the space-time Poisson model identifying larger cluster sizes and the STP model capturing more localized clusters. These findings provide valuable insights into the spatial and temporal dynamics of LSD outbreaks in Asia. The results of this study contribute to a better understanding of LSD epidemiology and offer essential information to support the development of regional and subregional prevention and control strategies.