LUMPY SKIN DISEASE(LSD) – AN EMERGING THREAT
Dr Aruna, M.V.Sc Scholar (Veterinary Medicine), College of Veterinary and Animal Science, Bikaner (RAJUVAS)
Introduction
Lumpy Skin disease (LSD) is an infectious, viral, occasionally fatal disease of cattle and buffalo caused by Lumpy skin disease virus (LSDV) and characterized mainly by nodules on skin covering whole of animal’s body. The severity of the disease varies among different breeds and strains of cattle.
First case was reported in Zambia in year 1919, then the disease subsequently spread to most African countries. In India, first case was reported in Odisha in August, 2019, followed by current outbreak in 2022 (July -September) in which Rajasthan had seen majority of deaths and the outbreak had caused great economic loss.
Morbidity ranges between 2-45% and Mortality is less than 10% but >15% observed in Rajasthan in current outbreak.
Etiology
Caused by Lumpy skin disease virus (LSDV), which belongs to genus Capripox virus, a part of Poxviridae family.
Antigenic similarity with sheep pox and goat pox.
It is not a zoonotic virus, which means it can’t transmit from animals to humans.
Transmission
It is a highly contagious disease.
According to United Nation FAO, infected animal shed virus through oral and nasal secretions and may contaminate feeding and water troughs. So, the disease can spread either through direct contact by vectors (mosquitoes, flies, ticks), contact with saliva or discharge from nose and eyes or through contaminated fodder and water.
Clinical Findings
According to FAO, incubation period of the disease is approx. 28 days (from infection to appearance of symptoms).
Mainly affects the skin and cause lumps formation, that’s why the name. Cutaneous nodules are formed, usually covering whole body (2-5 cm in diameter) that may later turn to ulcers followed by scabs over the skin, or may regress automatically.
Other signs include pyrexia, marked drop in milk yield, hypersalivation, inappetence, nasal and ocular discharge and emaciation.
Nodules may also develop within nasal and buccal mucus membranes. And, in some cases oedematous swelling may be observed in limbs leading to lameness.
Diagnosis and Treatment
Diagnosis is mainly based on the history and clinical observations. Other methods employed for diagnosis are – histopathology, virus isolation, PCR etc.
There is no specific antiviral drug for the disease. The treatment given is symptomatic and is focused mainly to prevent secondary bacterial infection, that usually aggravate the condition. So, antibiotics are given at high dose. Along with that antihistamines, anti-inflammatory, painkillers, anti-pyretic, mineral supplements, liver supportive therapy etc are given.
Once the animal has recovered, does not transmit the infection.
Prevention
- Control of animal movement, to and from the infected area
- Restrictions with affected animals and persons dealing with such animals
- Vector Control, using various physical and chemical methods
- Proper disinfection and cleaning of enclosures
- Proper disposal of carcass of infected animal
- Awareness programmes should be conducted regularly
Vaccination
Due to cross-protection within the genus Capripox Virus, Sheep pox virus vaccine have been widely used for lumpy skin disease virus.
An indigenous vaccine Lumpi -ProVacInd was developed recently by NRCE, Hisar in collaboration with IVRI, Bareilly. It is a live attenuated vaccine.
