Lumpy skin disease (LSD) in cattle has been spreading in many Indian states including Gujarat, Rajasthan, Punjab, Haryana, and Uttar Pradesh. The current outbreak of this disease started in April 2022, in Kutch, Gujarat, and by August 2022, about 57,000 cattle had died of LSD in various states and out of that 37,000 are in Rajasthan. The severity of the disease and death rate for buffalo are much lower due to their higher natural immunity as compared to cows. The central government has asked the affected states to boost the vaccination process to control the disease.
According to the 2019 livestock census, India has a cattle population of 192.5 million, and further, India is also the largest producer of milk in the world.
What is Lumpy Skin Disease?
Lumpy skin disease is caused by a virus in the family of Poxviridae, genus Capripoxvirus which affects cattle. Sheeppox virus (SSPV) and goatpox virus (GTPV) are the other members of the genus Capripoxvirus. The LSD virus mainly infects the cow and its progeny, and the Asian water buffalo. It is a contagious viral disease that affects cattle, causing fever and nodules on the skin, and could also lead to the death of the cattle.
Causes of Disease
The disease is transmitted by blood feeding insects like mosquitoes, flies, lice, and wasps by direct contact. It could also be transmitted through contaminated food and water. The nodules in the skin may cover the whole of the animal’s body, and lesions are often found in the mouth and upper respiratory tract. Agro-climates, communal grazing, biting-fly, and introduction of new animals are related to the occurrence of LSD. Scientists have been advising isolation of infected cattle that would help reduce the spread of infection. However, the large number of stray cattle makes this task difficult. This has probably been contributing to the rapid spread of the disease. The disease could be asymptomatic in some animals, which is how it could spread inconspicuously to others.
The disease entered India, Bangladesh, and China in 2019. As of now, there is no evidence of a zoonotic spread of the virus. Zoonosis is a process in which, a virus spreads from an animal on to humans as happened with COVID-19, which is zoonotic.
According to the 2021 report of the United Nations Food and Agriculture Organization (FAO), lumpy skin disease outbreaks occur as epidemics several years apart. There is no known reservoir of the virus. Also, it is not known where and how the virus survives between epidemics. The report further stated that since long, lumpy skin disease had been restricted to sub-Saharan Africa. The virus has spread to the Middle East and Turkey (now called Turkiye) over the past decade. From 2015 onwards, it has infected cattle in South-Eastern and Eastern Europe and Russia.
Effects of the Disease
Lumpy skin disease virus attacks the circulatory system of an animal, and causes vasculitis or inflammation of blood vessels and lesions in organs like liver, lungs, spleen, lymph nodes, etc. The epidermis, or outer surface of the skin, gets separated from the inner layer, leading to the formation of lumps or nodules on the body of the cattle. Fever, increased mucus secretion, salivation from the mouth, soft blisters like nodules all over the body, reduced milk production and loss of appetite are among the other symptoms. Autopsies carried out at the College of Veterinary Science and Animal Husbandry (CVSAH), Dantiwada, Gujarat, found that the virus had caused necrotising vasculitis (or the death of tissues) and fibrosis in various organs, leading to the death of cattle.
According to the National Library of Medicine at the National Centre for Biotechnology Information, the systemic effects of the disease include pyrexia, anorexia, dysgalactia, and pneumonia. LSD leaves the cattle with severe emaciation, loss of production of milk for several months, infertility, and in extreme cases, death. Recovery period may vary between two weeks to a month, and for those severely infected cattle, the recovery rate may be even slower.
Since the time this disease entered India, Bangladesh and China, the outbreaks of this disease have been reported from 20 Indian states and union territories, including Assam, Andhra Pradesh, Bihar, Chhattisgarh, Goa, Gujarat, Haryana, Jharkhand, Karnataka, Kerala, Maharashtra, Madhya Pradesh, Manipur, Odisha, Tamil Nadu, Telangana, Uttar Pradesh, and West Bengal. In 2020 and 2021, there were small outbreaks of this disease in cattle in some parts of Gujarat. At present, Rajasthan is the most affected state with almost 600–700 deaths of cattle reported per day.
Vaccine for the Disease
There is currently no specific antiviral for the disease and most treatment is symptomatic. According to the Union Minister for Fisheries, Animal Husbandry and Dairying, Parshottam Rupala, goat-pox vaccine is very effective and available. States have been advised to currently use the goatpox vaccine to control lumpy skin disease in cattle. About 1.5 crore doses are already administered to the ill cattle in affected states. The 1–ml dose of the vaccine is enough for the areas still not affected, while the affected areas must use a 3–ml dose of the vaccine.
The Indian Council of Agricultural Research-National Research Centre on Equines (ICAR-NRCE), Hisar, Haryana, in collaboration with ICAR-Indian Veterinary Research Institute (IVRI), Izatnagar, Uttar Pradesh, has developed a vaccine named ‘Lumpi-ProVacInd’, against lumpy skin disease. The union government is planning to commercialise the vaccine developed by these two institutes of the ICAR, at the earliest, to control the lumpy skin disease in cattle.
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