The First Lumpy Skin Disease Outbreak in Thailand (2021): Epidemiological Features and Spatio-Temporal Analysis

The first outbreak of lumpy skin disease (LSD) in Thailand was reported in March 2021, but information on the epidemiological characteristics of the outbreak is very limited. The objectives of this study were to describe the epidemiological features of LSD outbreaks and to identify the outbreak spatio-temporal clusters. The LSD-affected farms located in Roi Et province were investigated by veterinary authorities under the outbreak response program. A designed questionnaire was used to obtain the data. Space-time permutation (STP) and Poisson space-time (Poisson ST) models were used to detect areas of high LSD incidence. The authorities identified 293 LSD outbreak farms located in four different districts during the period of March and the first week of April 2021. The overall morbidity and mortality of the affected cattle were 40.5 and 1.2%, respectively. The STP defined seven statistically significant clusters whereas only one cluster was identified by the Poisson ST model. Most of the clusters (n = 6) from the STP had a radius <7 km, and the number of LSD cases in those clusters varied in range of 3–51. On the other hand, the most likely cluster from the Poisson ST included LSD cases (n = 361) from 198 cattle farms with a radius of 17.07 km. This is the first report to provide an epidemiological overview and determine spatio-temporal clusters of the first LSD outbreak in cattle farms in Thailand. The findings from this study may serve as a baseline information for future epidemiological studies and support authorities to establish effective control programs for LSD in Thailand.

Characterization of a Nigerian Lumpy Skin Disease Virus Isolate after Experimental Infection of Cattle

Lumpy skin disease virus (LSDV), together with sheeppox virus and goatpox virus, belong to the genus Capripoxvirus within the family Poxviridae. Collectively, they are considered the most serious poxvirus diseases of agricultural livestock. Due to their severe clinical course and consequent loss of production, as well as high mortality of naïve small and large ruminant populations, they are known to have a significant impact on the economy and global trade restrictions of affected countries. Therefore, all capripox diseases are classified as notifiable under the guidelines of the World Organization of Animal Health (OIE). Since the 1970s, several outbreaks of LSD have been recorded in Nigeria. Until now, only a little information on the virus strains leading to the reported outbreaks have been published, dealing mainly with the phylogenetic relationship of those strains and the description of field outbreaks. During the present study, we experimentally infected cattle with a low-passage Nigerian LSDV strain isolated from a skin sample of LSD positive cattle in Nigeria in 2018. Clinical, molecular and serological data indicate that this LSDV isolate is highly pathogenic in cattle since it induced a severe clinical course and approximately 33% mortality in naïve Holstein Friesian cattle after experimental infection.

Prevalence and Management Practices of Lumpy Skin Disease (LSD) in Cattle at Natore District of Bangladesh

Lumpy skin disease (LSD) is a potentially contagious viral disease in cattle, caused by the Lumpy skin disease virus (LSDV), which belongs to the family Poxviridae. The virus is suspected to spread via biological vectors such as mosquitoes, flies, ticks, and direct contact. It is a significant economic disease caused by a virus that causes significant losses in milk production, fertility, abortions, import restrictions, and, in some cases, death in the livestock animals. This study aimed to assess the current state of LSD and its management on several farms in the north-western region of Bangladesh. Data were obtained from two Upazilas in the Natore district (Natore Sadar and Baraigram) using a structured questionnaire. During the study period of 1 June to 20 December 2020, a total of 34 small farms and 87 animals were monitored. The OIE guidelines directed the diagnosis of LSD based on current clinical indicators. MS Excel and SPSS statistical software were used to evaluate all of the data. Morbidity, mortality, and case-fatality rates were found to be 64.70%, 2.94 %, and 4.53 % in Natore Sadar and 83.02 %, 3.77 %, and 4.55 % in Baraigram Upazilas, respectively. Female animals that were newly matured (2-4 years) were a larger prone to LSD infection (43.1%) than animals of other ages. A total of 34.43% illness was found in young bull cattle aged (2-4). Bull and heifer calves are also vulnerable populations, with reports of LSD infection leading to mortality. Limb swelling is a common clinical symptom, and LSD-positive young mature (2-4 year) cattle had the most significant rate (18.39%) of limb swelling. The farm hygiene practice is a critical determinant in the spread of LSDV, and a large proportion of cattle (48.27 %) infected with LSD were on farms with poor hygienic management, compared to good (01.14 %) and medium (01.14 %) hygienic management practices (26.43 %). Despite the fact that mosquito nets help prevent mosquitoes, most owners (91.17 %) did not use one in their cattle barn at night. More study is needed in Bangladesh to improve the clinical management of LSD, identify risk factors, and understand the molecular characteristics of diseases.