Lumpy Skin Disease Virus

In this article, we will discuss a deadly Lumpy Skin Virus that generally affects cattles. This virus is highly effecting dears now a days so this become useful for those who are preparing for competitive exams as well as for interviews.

Why in News :

Recently, in some states of India, cases of infection of Lumpy skin disease in cattle have been reported. Most of the cases are from Rajasthan and Gujarat. So far 1,20,782 animals have been infected with this Lumpy virus in Rajasthan and 5,807 animals have died in them. Up to 90 percent of cows are infected with the Lumpy virus and most cows have died due to this.

History of Lumpy Skin Disease (LSD) :

In Zambia, Lumpy skin disease was first seen as an epidemic in 1929. Initially, it was thought to be the result of poisoning or hypersensitivity to insect bites. Additional cases occurred between 1943 and 1945 in Botswana, Zimbabwe, and South Africa. Approximately 10 million cattle were affected by a panzootic infection in South Africa in 1949, causing huge economic losses. LSD spread throughout Africa in the 1950s and 1980s, affecting livestock in Kenya, Sudan, Tanzania, Somalia, and Cameroon.

In 1989 there was an outbreak of LSD in Israel. This outbreak was the first case of LSD north of the Sahara desert and outside of the African continent. This particular outbreak was thought to be the result of infected Stomoxys calcitrans being carried on the wind from Ismailiya in Egypt. During 37 days between August and September 1989, fourteen of the seventeen dairy herds in Peduyim were infected with LSD. All livestock was slaughtered, as well as small flocks of sheep and goats in the village. Over the past decade, cases of LSD have been reported in the Middle East, Europe, and West Asia regions.

What is the LSD :

Lumpy skin disease (LSD) is an infectious disease of cattle caused by a virus of the Poxviridae family, also known as the Neethling virus. The disease is characterized by fever, enlarged superficial lymph nodes, and numerous nodules (2 to 5 cm (1 to 2 inches) in diameter) on the skin and mucous membranes (including the respiratory and gastrointestinal tracts). Infected cattle may also develop limb swelling and display lameness. The virus has important economic implications as it causes permanent damage to the skin of affected animals, reducing the commercial value of their skin. In addition, the disease often causes chronic weakness, low milk production, poor growth, infertility, miscarriage, and sometimes death.

Classification of Contagious LSD :

The contagious Lumpy skin disease virus (LSDV) is a double-stranded DNA virus. LSD is a member of the capripoxvirus genus of Poxviridae. Capripoxviruses (CaPV) represent one of eight genera within the Chordopoxvirus (ChPV) subfamily. The capripoxvirus genus includes LSDV, sheep pox, and goat pox. CaPV infections are usually host-specific within specific geographic distributions, although they are serologically indistinguishable from each other.

Structure of Contagious LSD VIRUS :

Like other viruses in the family Poxviridae, Capripoxviruses have a brick-like shape. Capripoxvirus virions differ from orthopoxvirus virions in that they have a more oval profile as well as larger lateral bodies. The mean size of capripoxvirions is 320 nm by 260 nm.

The Genome of Contagious LSD VIRUS – 

The virus has a 151 kbp genome, consists of a core coding region surrounded by identical 2.4 kbp inverted terminal repeats, and contains 156 genes. There are 146 conserved genes when comparing LSDV with Cordopoxviruses from other genera. These genes encode proteins involved in mRNA transcription and biogenesis, nucleotide metabolism, DNA replication, protein processing, virulence structure and assembly, and the viral virulence and host range. Within the core genomic region, the LSDV genes share a high degree of collinearity and amino acid identity with the genes of other mammalian poxviruses. Examples of viruses with identical amino acids include Suipoxvirus, Ortapoxvirus, and Leporipoxvirus. In the terminal regions, however, the collinearity is interrupted. In these regions, the poxvirus homologues are either absent or share a lower percentage of amino acid identity. Most of these differences involve genes that are likely to be 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 proteins, which are found in other genera of poxvirus.

Transmission of LSD VIRUS :

LSDV outbreaks are associated with high temperatures and high humidity. It is generally more prevalent during the humid summer and autumn seasons, especially in coastal areas or near waters. However, outbreaks can also occur during the dry season. Insects that feed on blood, such as mosquitoes and flies, act as mechanical carriers to spread disease. No single vector species have been identified. Instead, the virus has been isolated from species such as Stomoxys, Biomyia fasciata, Tabanidae, Glossina, and Culicoides. The specific role of each of these insects in the transmission of LSDV is being evaluated. Lumpy skin disease outbreaks tend to be sporadic, depending on animal movements, immune status, and wind and rain patterns, which affect vector populations.

The virus can be transmitted through blood, nasal discharge, tear secretions, semen, and saliva. The disease can also be transmitted through infected milk to nursing calves. In experimentally infected cattle, LSDV was found in saliva 11 days after suffering from fever, in semen after 22 days, and in skin nodules after 33 days. The virus is not found in urine or feces. Like other smallpox viruses, which are known to be highly resistant, LSDV can remain viable in infected tissue for more than 120 days.

What to do if Cows are infected with a Lumpy Virus :

• Immediately inform the nearest Veterinary Officer
• Isolate infected cows from healthy cows 
• Restrict movement of infected cows 
• Always give clean water to the cows 
• Drink boiled milk of infected cows 
• Use insecticide to protect against mosquitoes, flies, mites, etc. 
• Spray phenyl/sodium hypochlorite in cattle shelters, cowsheds, and animal barns.
• Keep the caregiver of sick animals away from healthy people.