What is the Lumpy Skin Disease?
According to a report by GAVI, the Global Alliance for Vaccines and Immunisation, the Lumpy Skin Disease (LSD) disease is caused by a virus called the Capripoxvirus and is “an emerging threat to livestock worldwide”. It is genetically related to the goatpox and sheeppox virus family.
LSD infects cattle and water buffalo mainly through vectors such as blood-feeding insects. Signs of infection include the appearance of circular, firm nodes on the animal’s hide or skin that look similar to lumps.
Infected animals immediately start losing weight and may have fever and lesions in the mouth, along with a reduced milk yield. Other symptoms include excessive nasal and salivary secretion. Pregnant cows and buffaloes often suffer miscarriage and in some cases, diseased animals can die due to it as well.
How can the spread of the disease be prevented?
Successful control and eradication of LSD relies on “early detection…followed by a rapid and widespread vaccination campaign”, as per the WOAH. Once an animal has recovered, it is well protected and cannot be the source of infection for other animals.
In his interview with The Indian Express, Prof J B Kathiriya, also spoke about the measures to protest against the viral infection. He said: “The first thing is, they should sanitise cattle-sheds by eliminating vectors through application of insecticides and spraying disinfectant chemicals. They should isolate the infected cattle immediately from the healthy stock and contact the nearest veterinarian for treatment of the infected animal. This is necessary as otherwise the virus may prove fatal.”
“Secondly, they should report the outbreak to the state government so that the rest of the healthy herd can be vaccinated using goat pox vaccine,” said Prof Kathiriya. He added that cattle with healthy immune systems will recover from the disease in some days.
Another challenge is the disposal of the dead animals as improper handling of the carcasses can cause health and sanitation issues. Proper disposal of the carcasses can include incineration or burning of the bodies at high temperatures, along with disinfection of premises, as per the WOAH.
The virus has a 151-kbp genome, consisting of a central coding region which is bounded by identical 2.4 kbp-inverted terminal repeats and contains 156 genes. There are 146 conserved genes when comparing LSDV with chordopoxviruses of other genera.These genes encode proteins which are involved in transcription and mRNA biogenesis, nucleotide metabolism, DNA replication, protein processing, virion structure and assembly, and viral virulence and host range. Within the central genomic region, LSDV genes share a high degree of collinearity and amino acid identity with the genes of other mammalian poxviruses. Examples of viruses with similar amino acid identity include suipoxvirus, yatapoxvirus, and leporipoxvirus. In terminal regions, however, collinearity is interrupted.In these regions, poxvirus homologues are either absent or share a lower percentage of amino acid identity. Most of these differences involve genes that are likely associated with viral virulence and host range. Unique to Chordopoxviridae, LSDV contains homologues of interleukin-10 (IL-10), IL-1 binding proteins, G protein-coupled CC chemokine receptor, and epidermal growth factor-like protein, which are found in other poxvirus genera.