Spatio-temporal patterns of lumpy skin disease outbreaks in dairy farms in northeastern Thailand

Abstract

In 2021–2022, there were numerous outbreaks of lumpy skin disease (LSD) affecting cattle farms across Thailand. This circumstance was the country's first encounter with an LSD outbreak. Thus, a better understanding of LSD epidemiology is necessary. The aim of this study was to determine the spatio-temporal patterns of the LSD outbreaks in dairy farming areas. Data from LSD outbreak investigations collected from dairy farms in Khon Kean province, northeastern Thailand, were analyzed using spatio-temporal models including space-time permutation, Poisson, and Bernoulli models. LSD outbreaks were found in 133 out of 152 dairy farms from May to July, 2021. The majority of dairy farms (n = 102) were affected by the LSD outbreaks in June. The overall herd attack, morbidity and mortality rates were 87, 31, and 0.9%, respectively. According to the results of all models, the most likely clusters were found in the northern part of the study area. The space-time permutation and Poisson model identified 15 and 6 spatio-temporal outbreak clusters, respectively, while the Bernoulli model detected only one cluster. The most likely clusters from those models cover radii of 1.59, 4.51, and 4.44 km, respectively. All farms included in the cluster identified by the space-time permutation model were also included in the cluster identified by the Poisson model, implying that both models detected the same outbreak area. Furthermore, the study results suggested that farmers who own farms within a one km radius of the LSD outbreak farm should be advised to implement more stringent insect vector control measures to prevent disease spread. This study provides better insights into the spatio-temporal pattern of clusters of LSD in the outbreak area. The findings of this study can support authorities in formulating strategies to prevent and control future outbreaks as well as prioritizing resource allocation to high-risk areas.

Lumpy Skin Disease: A Systematic Review of Mode of Transmission, Risk of Emergence and Risk Entry Pathway

“…Regarding the spread modalities, the studies included in this literature review [ 54 , 58 , 60 , 69 ] reported that short-distance spread (i.e., between herds) was most likely attributed to a dispersal by arthropod vectors, whereas long-distance spread (i.e., transboundary, introduction into new geographical areas) was related to livestock movements. Both short- and long-distance spreads are associated with climatic conditions, especially a high temperatures and rainfalls.…”

“…The authors inferred that transmission occurred over <5 km distances, which can be attributed to vectors, but with an appreciable probability of transmission over longer distances, that can be related to livestock movements [ 60 ]. Spatio-temporal analysis of LSD outbreaks that affected dairy farms in north-eastern Thailand discovered that these outbreaks occurred in numerous dairy farms over a short period of time, and that several affected farms were concentrated in the area [ 58 ]. Based on these findings and on the fact that cattle movements between dairy farms are few, the spread was attributable to vectors.…”

Lumpy Skin Disease Outbreaks in Africa, Europe, and Asia (2005–2022): Multiple Change Point Analysis and Time Series Forecast

“…This finding indicates that Thailand had the highest number of LSD outbreak reports compared to other countries in Asia in 2021. Because it was the first time Thailand faced this threat, LSD outbreaks were found in cattle herds across the country, causing serious economic loss to the cattle industry [ 25 , 61 ].…”

Understanding the research advances on lumpy skin disease: A comprehensive literature review of experimental evidence

“…Then it was spread into Yi li, Xinjiang Province, China in 2019. In the following 2 years, the disease spread to southern and eastern parts of China and the countries in South Asia, including Nepal, Bhutan, Vietnam, Thailand and Myanmar ( Pseudo-urticaria, 1931 ; Mulatu and Feyisa, 2018 ; Arjkumpa et al, 2021 ; Punyapornwithaya et al, 2022 ). By 2022, the disease had spread east and north to Mongolia and Eastern Siberia ( Figure 2 ).…”