Lumpy skin disease outbreaks in Egypt during 2017-2018 among sheeppox vaccinated cattle: Epidemiological, pathological, and molecular findings

PLoS One. 2021 Oct 20;16(10):e0258755. doi: 10.1371/journal.pone.0258755. eCollection 2021.

Abstract

The General Organization of the Veterinary Services in Egypt has adopted a sheeppox vaccination policy to control lumpy skin disease (LSD) in cattle. Over the course of the last two years, recurrent outbreaks were reported, with animals showing severe clinical signs and consequentially higher fatalities than that of cases reported in previous LSD outbreaks. A total of 1050 cattle showing typical clinical signs suggestive of LSD were clinically and pathologically investigated during 2017-2018. Skin nodules were collected and lumpy skin disease virus (LSDV) was screened in collected skin samples using PCR for the RPO-30 gene. Furthermore, the entire P32 protein coding gene was sequenced. Histopathology and immunohistochemistry of the skin nodules were also conducted. The obtained results showed an overall mortality rate of 6.86%. LSDV was confirmed in all the examined nodules as evidenced by immunohistochemistry and positive PCR amplification of the RPO30 gene. Sequencing analysis of the P32 gene revealed a highly conserved nature and genetic stability of the LSDV. The results of the present study show that the current vaccination protocol was not effective for a multitude of reasons. These results also serve as evidence for a strong recommendation of an amendment of homologous vaccine use aside from a complete coverage of cattle populations in order to reduce the incidence of LSD among cattle population in Egypt.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Animals
  • Cattle
  • Disease Outbreaks / veterinary*
  • Egypt / epidemiology
  • Evolution, Molecular
  • Female
  • Lumpy Skin Disease / epidemiology*
  • Lumpy Skin Disease / mortality
  • Lumpy Skin Disease / virology
  • Lumpy skin disease virus / classification*
  • Lumpy skin disease virus / genetics
  • Lumpy skin disease virus / isolation & purification
  • Male
  • Mortality
  • Phylogeny
  • Sequence Analysis, DNA
  • Vaccination / veterinary*
  • Viral Proteins / genetics*

Substances

  • Viral Proteins

Grants and funding

The authors acknowledge the support of Taif University Researchers Supporting Project Number (TURSP-2020/11), Taif University, Taif 21944, Saudi Arabia.