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

Abstract

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.

The immune response to lumpy skin disease virus in cattle is influenced by inoculation route

“…This was most obvious at later timepoints (from 15 dpi). A similar pattern of responses has been observed in previous studies (22, 60, 61), and is likely due to the higher virus load in the clinical calves providing more antigenic-stimulation.…”

Experimentally controlled study indicates that the naturally occurring recombinant vaccine-like lumpy skin disease strain Udmurtiya/2019, detected during freezing winter in northern latitudes, is transmitted via indirect contact

“…Half of the animals were infected and shared the same airspace with non-infected animals and since representatives of both groups of animals developed LSD, it clearly indicates an alternative indirect contact mode of transmission. In-contact transmission between infected and uninfected animals was suggested when a classical LSDV field strain (LSDV-V/281-Nigeria) was used as an inoculum ( 31 ). The authors reported PCR positive results from nasal swabs from the in-contact animals, but these animals did not produce any clinical signs of viral infection, nor had viraemia detected from blood, nor seroconverted, nor were virus isolation attempted ( 31 ).…”

“…In-contact transmission between infected and uninfected animals was suggested when a classical LSDV field strain (LSDV-V/281-Nigeria) was used as an inoculum ( 31 ). The authors reported PCR positive results from nasal swabs from the in-contact animals, but these animals did not produce any clinical signs of viral infection, nor had viraemia detected from blood, nor seroconverted, nor were virus isolation attempted ( 31 ). Since there is no scientific justification to suggest that poxviruses display local replication without disseminating via the lymph and blood ( 32 ), additional studies are required to clarify this issue concerning classical LSDV strains that have thus far been principally associated with transmission via insects.…”

Molecular identification and characterization of Lumpy skin disease virus emergence from cattle in the northeastern part of Thailand

“…In Thailand, LSD is a newly emerging infectious disease with an incidence not previously described in cattle until March 2021 [ 15 ]. LSDV DNA has been extracted from nodules, lymph nodes, ulceration, milk, secretions, semen, and blood of infected cattle [ 8 16 17 29 ]. In the present study, the LSDV was detected in the blood of infected cattle by PCR targeting P32 antigen gene.…”

“…LSDV is a double-strand DNA virus. The genome of this virus is easy to detect in a variety of specimens, including nodules, ulceration, secretions, semen, and blood of infected cattle [ 8 16 17 ]. Polymerase chain reaction (PCR) and modified PCR methods targeting p32 and GPCR genes are used widely to detect and characterize LSDV [ 18 19 ].…”