Lumpy Skin Disease: A Looming threat to thriving Economy
Dr. Smruti Smita Mohapatra
Research Fellow
Verghese Kurien Centre of Excellence
Institute of Rural Management Anand, Gujarat
Email: simplysmruti@gmail.com
Introduction
Lumpy skin disease (LSD) is caused by lumpy skin disease virus (LSDV), a virus from the family Poxviridae, genus Capripox virus. Sheep pox virus and Goat pox virus are the two other virus species in this genus. Lumpy skin disease is caused by a Capripox virus that affects cattle and buffalo. Internationally and nationally it is spreading rapidly. The virus is highly host specific and does not cause disease in humans. There is no risk from consuming dairy products. Lumpy skin disease virus is spread primarily by biting insects such as flies and mosquitoes, and ticks. It can be transmitted by fomites, and in some cases, from animal to animal. The disease can be also be spread through contaminated feed, water, and equipment. The virus is present in high concentrations in the skin nodules and scabs on affected animals. Lumpy skin disease is a notifiable disease.
Clinical signs
Fever may exceed 41°C (105°F). There is marked reduction in milk yield in lactating cattle. There is depression, anorexia and emaciation. Rhinitis, conjunctivitis, excessive salivation and enlarged superficial lymph nodes are observed in cattle. Pregnant cows may abort and be in anoestrus for several months. Bulls may become permanently or temporarily infertile. Cutaneous nodules of 2–5 cm in diameter develop, particularly on the head, neck, limbs, udder, genitalia and perineum within 48 hours of onset of the febrile reaction. These nodules are circumscribed, firm, round and raised, and involve the skin, subcutaneous tissue and sometimes even the underlying muscles. Large nodules may become necrotic and eventually fibrotic and persist for several months (“sitfasts”); the scars may remain indefinitely. Small nodules may resolve spontaneously without consequences.
Diagnosis
Before collecting or sending any samples, the proper authorities should be contacted. Samples should only be sent under secure conditions and to authorized laboratories to prevent the spread of the disease.
Economic importance
LSD leads to emaciation, abortion, mastitis and loss of milk production. World Organization for Animal Health (founded as OIE) states that lumpy skin disease is a pox viral disease with significant morbidity in cattle. Economic losses result from loss of condition, decreased milk production, abortions, infertility and damaged hides. There is no evidence that LSDV can infect humans. A manual for veterinarians released by FAO on lumpy skin disease sates that the Lumpy skin disease (LSD) is a viral disease of cattle that has dramatic effects on rural livelihoods, which strongly dependent on cattle. The disease slashes milk production and may lead sterility in bulls and fertility problems in females. It damages hides, and causes death due to secondary bacterial infections
Immune response, control and prevention of LSD
Restriction should be enforced with affected animals and the persons dealing with infected animals. Movement of people to and from the affected area should be restricted. The animal handlers and those attending to the affected animals should keep away from healthy animals. It is therefore, of utmost importance to ensure these safety measures. The infected villages be identified so that precautionary plans will be carried out in a specific area and ring vaccination will be carried out in villages upto 5 km around the affected village. Cattle and buffaloes should be vaccinated with available Goat pox vaccine (cattle and buffalo at the age of 4 months and above through S/C route) with 103.5 TCID50 of GTPV vaccine (Uttarkashi Strain). The dose of 103.0 TCID50 (same dose of vaccine for goat against goat pox) can be used for prophylactic vaccination/ring vaccination in cattle and buffalo. Affected animals should not be vaccinated. Preventive vaccination should also be undertaken in high risk areas like border area of affected district and state and animals should be identified and documented. The staff and vaccinators should be trained for vaccination drive including storage and preparation of vaccine, dosing and injection and identification of animals.
Bio-security measures
Isolation of sick animal from the healthy animals is essential. Clinical surveillance against LSD in affected districts and around surrounding villages should be intensified. The buffaloes should be kept separately till complete recovery of the affected animals, if reared together. Disinfection of premises at regular intervals is necessary. Ecto-parasiticide should be applied to healthy animals on the infected and on surrounding farms. The persons dealing with the infected animal should wear gloves and face mask. Care should be taken to report any unusual sickness of other animals to nearest veterinary hospital and dispensary. Hygiene practices should be followed at the animal farm and by the people in area where animals are infected. Farms with affected animals should be visited regularly by the field veterinarians until all the cases are recovered. The veterinary staff should take all precautionary hygiene measures to avoid further spread of disease to other farms/households. In case of mortality, carcass should be disposed of by deep burial method observing all hygienic measures. Cattle markets located within 10 km radius of the epicentre of infection should be closed. Trade of live cattle, participation in fairs, shows should be banned immediately upon confirmation of the disease in the affected areas.
Control of vector population in the premises and the animal body should be carried out using the insecticide, repellents and other chemical agents. Affected premises, vehicles plying through the affected animal holdings should be carried out with appropriate chemicals / disinfectants – Ether (20%), chloroform, formalin (1%), phenol (2% /15 minutes), sodium hypochlorite (2-3%), iodine compounds (1:33 dilution) and quaternary ammonium compounds (0.5%). Mass awareness campaign to be taken up to make the public aware of the disease and report to the veterinary authority immediately when suspected cases are detected. This will help in prevention and control of LSD.
Strict implementation of advisories is required followed by movement restriction and isolation of affected animals. Movement control of vehicle, animals from affected area to free area. Disinfection measures to be followed strictly in liaison with Municipal bodies and administration including regular fogging and lime spray in the infected and surrounding area Stray cattle should be monitored regularly and the affected animals should be isolated under veterinary care with the help of municipal and administrative authorities. Waste disposal including feed, fodder and dead animal to be followed as per protocol and scientific method with marking and displayed safety guidelines. Animal movement from affected area to be monitored to prevent spread of the infection. Animal trade and fare should not be allowed in the affected area. Vehicle passing through the infected area should be monitored and disinfected. Insecticides spray and fogging to be undertaken in the animal sheds, common grazing area, veterinary hospital and dispensaries, animal gathering spots and animal movement tracks to control vectors like mosquito, flies, ticks, fleas etc. Surveillance of vector should also be undertaken by sending the samples to ICAR-NIHSAD to understand disease epidemiology and accordingly making control strategies. Monitoring of pastures, grazing area, water bodies, feed and fodder is needed to prevent contamination by infected animal. Infected feed, fodder and bedding material should not be used and disposed scientifically. Infected animals should be kept separately in isolation with close monitoring till recovered and should not be kept in same animal shed. The milk of infected animals should not be used and mixed in the milk of healthy animals. Unnecessary post-mortem and sampling of infected animals should be avoided so that disease may not spread during such operations. The staff should wear all preventive gears during PM and sampling. The sampling should be done as per the prescribed standard operating procedure and protocol with due care at all times and proper and safe transport shall be ensured. Sampling should only be done by expert personnel by the veterinarian or under veterinary supervision. Except in unavoidable circumstances, the treatment of infected animal should be done through oral medication and topical application to avoid spreading of disease through treatment procedures and contamination of treatment accessories and personnel during treatment. The veterinary hospitals and dispensaries should have proper supply of medicines, supplements, disinfectants, treatment accessories, foggers, awareness material PPE kits and other related items at all times. Control room and 24×7 toll free number to be activated to address the issues of farmers immediately and also awareness. Role of MVUs should be increased in awareness, treatment and vaccination drive and the MVU operating in infected area should not enter the free area and if required proper disinfection protocol should be followed. Door to door awareness and vaccination drive should be undertaken with the help of NGOs, village leaders, youths, cooperatives, school teachers and other stakeholders. Milk collection centers should educate the farmers at the time of milk collection and ensure healthy milk collection without mixing of the milk of infected animals. The consumption and transport of raw milk of infected animal should be discouraged. Group grazing area and animal groups should be monitored and vaccinated and the infected animals should be immediately separated and kept under isolation under veterinary care. Special care should be taken to monitor the movement of animals from affected districts and states and round the clock check post with disinfection system should be activated and documented. Veterinarians and paraveterinarians working in the infected zone should not be deputed for other works so that their services are available round the clock and they can contribute effectively in disease control programme. Proper TA/DA and incentives should be given and announced for veterinarians, paraveterinarians and other staff to motivate them in disease control operations.
Way forward
There is no treatment for Lumpy Skin Disease. It is very important to check regularly all the animals. Any suspicion of Lumpy Skin Disease must be notified immediately to a veterinarian and the veterinary services. Notification is essential to limit further spread of the disease. One Health approach is the need of the hour.
References
- Web sources of FAO and OIE
- Guidelines for Prevention of LSD, Department Of Animal Husbandry & Dairying, Govt. of India
