Lumpy Skin Disease (LSD): an Emerging Disease in India
Lumpy Skin Disease (LSD) was first identified in 1929 in Zambia after which it became endemic in many African countries. Of late the disease has been recorded and confirmed even in India.
Lumpy skin disease (LSD) is a viral disease caused by the lumpy skin disease virus (LSDV), a member of the Capripoxvirus genus of the Poxviridae family. It is a transboundary disease of economic importance affecting cattle and water buffaloes. The disease is transmitted by arthropod vectors (mosquitoes, biting flies, Culicoides midges and three blood-sucking hard ticks) which act as mechanical vector and causes high morbidity and low mortality.
The disease is endemic in African and Middle East countries but has started spreading to Asia and other countries. It is on the OIE (World Organisation for Animal Health) list of notifiable diseases.It has been recently reported from China and Bangladesh share borders with India. LSD has recently been reported first time in India with 7.1% morbidity among cattle. July 2019 marked the first known introduction of LSD into South Asia, with Bangladesh officially reporting an outbreak (OIE, 2020). In India, the disease first appeared in the West Bengal state in August 2019 and spread to at least 15 states within 16 months. Generally, fever, anorexia, characteristic nodules on the skin mucous membrane of the mouth, nostrils, udder, genitals, rectum, drop in milk production, abortion, infertility and sometimes death are the clinical manifestations of the disease. Major clinical signs include skin nodules all over the body, fever, lacrimal discharge, nasal discharge, anorexia, decreased milk yield, emaciation, depression and reluctance in movement.
The economic impact of LSD on South, East and Southeast countries was estimated to be up to USD 1.45 billion in direct losses of livestock and production. The detection of an exotic disease may have severe trade implications for infected countries. While mortality rates in cattle are often low, the relatively high morbidity of LSD once introduced into naïve populations can lead to significant income losses for farmers brought about by decreased milk production, damaged hides, emaciation of animals, infertility and abortions. Subsequent trade bans or other movement restrictions in affected countries place an economic strain on the cattle industry, severely impacting all actors along the value chain. The prevention and control of lumpy skin disease can be done by following four ways- movement control (quarantine), vaccination, slaughter campaigns and management strategies.
There are three licensed vaccines for lumpy kin disease: lumpy skin disease virus (LSDV) Neethling strain vaccine, Kenyan sheep and goat pox (KSGP) O-180 strain vaccines and Gorgan goat pox (GTP) vaccine. Till now in India, no vaccine is available for LSD, but goat pox virus (GTPV) and sheep pox virus (SPPV) vaccines have been tried and provide a certain degree of protection to cattle. Currently, researchers are trying to develop a successful vaccine in India for the prevention and control of the lumpy skin disease virus.
Causes of Lumpy Skin Disease in Cattle
The disease is caused by a viral agent commonly called Lumpy Skin Disease Virus (LSDV). It belongs to the poxvirus family and bears similarities to sheep and goat pox. The virus is very resilient in that it can survive even in harsh temperature and is inactivated only above 55oC if exposed for 2 hours. It can be recovered from skin nodules kept on –80°C for 10 years and infected tissue culture fluid stored at 4°C for 6 months. It is also resilient to a wide pH range pH 6. 6–8. 6. It is susceptible to ether (20%), chloroform, formalin (1%). It is also susceptible to phenol (2%/15 minutes), sodium hypochlorite (2–3%), quaternary ammonium compounds (0.5%).
The virus remained for long periods in dried lesions, very resistant to inactivation, and can survive in necrotic skin nodules more than a month. The virus is inactivated in sunlight but can survive for many weeks if the barn is devoid of sunlight and dark. It is therefore difficult to get rid of the virus once there is an outbreak.
Morbidity rate varies between 10 and 50%, whereas mortality is low less than 5%. Although the virus belongs to the sheep/ goat pox family, this virus is very host-specific, can cause disease only in cattle and water buffalo. The morbidity and mortality, however, are higher in crossbreds compared to indigenous cattle. The virus has not been reported from wildlife. The virus is not known to be transmitted to humans.
Mode of Transmission
The main route of transmission is barthropod vectorsor, mosquitoes, biting flies, and male ticks. Transmission through the feed, water, and direct contact with infected skin is not known to be an important route of transmission. For transmission to occur the virus must be injected into the skin. Needle transmission from infected to clean animal there is a possibility. The virus is present in abundance in skin lesions, blood, saliva, ocular discharge for more than 35 days. The virus is also excreted in the semen of infected bulls, but the role of semen in the transmission of the disease is not known. There is only one report of transplacental transfer of the virus. It does not exhibit latency and the recrudescence of disease does not occur.
Diagnosis of lumpy skin disease
Diagnosis is not a big challenge as the symptoms are very typical. Initially, there is high fever that may exceed 41°C and in the case of lactating animals, there is a reduction in milk. The animal appears severely depressed, loss of appetite, and rapid loss of weight. In some cases rhinitis, conjunctivitis, excessive salivation, swollen lymph nodes. The typical lesions are cutaneous nodules of 2–5 cm in diameter particularly on the head, neck, limbs, udder, genitalia, and perineum within 48 hours of the onset of the febrile reaction. These nodules are firm to touch, round, and raised deep into the skin, subcutaneous tissue. The nodules become necrotic and can be observed for several months. Like pox lesions, the scars may remain for a long time, especially if the lesions were deep.
In a few cases, limbs and other ventral parts of the body, such as the dewlap, brisket, scrotum, and vulva, may be oedematous, causing difficulty in movement. If the bulls are infected these may become permanently or temporarily infertile. In the case of pregnant animals, abortion and temporary infertility may also be recorded. When the lesions are severe it may take a long time to recover due to emaciation, and secondary complications such as mastitis, pneumonia, and necrotic skin plugs. The disease may be confused with herpes mammillitis and cowpox, dermatophilosis, demodicosis, severe generalized insect bites.
Laboratory diagnosis: For confirmation of the diagnosis PCR is, ideal, for which skin nodules, scabs, saliva, nasal secretions, and blood are suitable samples.
Treatment and Control
It is a viral disease, hence there is no specific treatment. To take care of the secondary infection and severe inflammatory response non-steroidal anti-inflammatory drugs may be administered.
Early detection and rapid vaccination coverage are keys to effective prevention of the outbreak. As the virus is transmitted through insect bites, vector control is critical. In a small-hold system, ensuring that every time a sterilized needle is used only for a single animal. “Homologous” LSDV live attenuated vaccine strain, for example, “Neethling” LSD strain, “Heterologous” sheep pox or goat pox virus live attenuated vaccine strain.
M.V.Sc., Ph.D. (Canada)
Ex-Dean, Faculty of Veterinary Science and Director of Instruction, MAFSU
What is lumpy skin disease and what are its symptoms?
Lumpy virus skin disease (LSD) is an infectious disease in cattle caused by a virus. This disease causes fever in cattle. It enlarges/swells superficial lymph nodes and numerous nodules (2-5 cm in diameter) on the skin and mucous membranes.
Infected cattle may develop swelling in their limbs and exhibit lameness. This virus can cause permanent damage to the skin of affected cattle. Additionally, the disease often causes chronic debility, low milk production, poor growth, infertility, miscarriage and sometimes death.
Major Symptoms of Lumpy Virus Skin Disease
The onset of fever occurs about a week after infection with the virus.
The initial fever may exceed 41 °C (106 °F) and may persist for up to a week.
At this time, all superficial lymph nodes become enlarged. Nodules appear seven to nineteen days after virus infection. With the appearance of nodules, the discharge from the eyes and nose becomes mucopurulent (pus forms at the site of inflammation during infection).
Ways to protect cattle from Lumpy Skin Disease
This disease is spreading among other cattle through mosquitoes and flies due to uncleanliness. Therefore, livestock owners and cowsheds should keep their cattle clean at the place where they are tied. Apart from this, it has also been advised to adopt the following measures.
1.Isolate the animal from other cattles when the initial symptoms of this disease are seen. Contact nearest veterinary center for treatment.
2. Arrange fodder, water and grains for sick cattles in separate utensils. Prevent movement of cattles in diseased areas.cattles
3. Where there are such cattles, burn neem leaves and smoke them, so that flies, mosquitoes etc. can be driven away.
4. Fill the cracks or holes in the walls of the animal habitat with lime. With this, camphor tablets can also be kept, it keeps flies and mosquitoes away.
5. Spray 2% to 3% solution of sodium hypochlorite to make the cattles bacteria free.
6. Clean the objects and places in contact with the dying cattles with phenyl and red medicine etc.
7. Bury the animal dead from infectious disease outside the village in a pit about one and a half meters deep with lime or salt.
Lumpy Skin Disease is transmitted by blood-feeding insects such as ticks or even flies and mosquitoes. It is a viral disease affecting cattle.
The Lumpy Skin Disease (LSD), which has been linked to numerous animal deaths in seven states and one union territory, has raised serious concerns. Animal imports have been prohibited in the areas where cases have been discovered by the administration as a preventative measure. The Lumpy virus, however, has only been identified in cows and buffaloes.
WHAT IS LUMPY SKIN DISEASE?
Cattle are susceptible to the infectious viral disease known as a lumpy skin disease (LSD). According to some reports, the disease is spread by ticks or other blood-feeding insects like some types of flies and mosquitoes. Fever and skin lumps are among the disease’s symptoms, which can also be fatal.
SYMPTOMS:
The infectious disease is brought on by the Poxviridae virus, also referred to as the Neethling virus. Enlarged lymph nodes, lumpy skin, fever, and trouble moving are a few of the basic signs of the illness in cattle.
CAN HUMANS GET IT?
Medical professionals have affirmed that even if people come into contact with sick cattle, the disease does not transmit to people.
Animals can be healed of the sickness, but the virus can still harm the milk from such an animal.
TREATMENTS:
On August 10, the indigenous Lumpi-ProVac vaccine was introduced by Union Minister for Agriculture and Farmers Welfare Narendra Singh Tomar to safeguard livestock against Lumpy Skin Disease.
MEDIA REPORT ON LUMPY SKIN DISEASE IN INDIA
The National Equine Research Centre in Hisar, Haryana, and the Indian Veterinary Research Institute in Izzatnagar, Bareilly, jointly produced the vaccine.
Goat pox vaccine ‘100% effective’ against LSD, outbreak has ebbed in parts of Gujarat: Rupala
The goat pox vaccine is “100 per cent effective” against the Lumpy Skin Disease (LSD) too, Union Minister of Fisheries, Animal Husbandry and Dairying, Parshottam Rupala, said Thursday, as the country battles an outbreak that has so far affected 15 lakh cattle.
The LSD outbreak has been reported from “6-7” states including Gujarat, Rajasthan, Punjab, Haryana, Uttar Pradesh and Andhra Pradesh, the minister said, adding both the Centre and the state governments are working hard to contain its spread.
The minister said the disease has already ebbed in around 15 districts of Gujarat while some cases are being reported from Rajasthan.
“We have adequate (goat pox) vaccines…work is on to protect the animals,” Rupala said at a press conference ahead of the IDF World Dairy Summit 2022 in Greater Noida. “Goat pox [vaccine] is 100 per cent safe and 100 per cent effective.”
The minister said while “only 1 ml dose” of the goat pox vaccine is sufficient to help fight LSD in areas where no case has been reported, doses of 3 ml each can be administered in cattle where an outbreak has been reported.
“There is no confusion about the quantity of vaccine doses,” he added.
Among the states hit by LSD are the country’s top milk producers: Uttar Pradesh alone contributes 18% to India’s total milk production. Rupala, however, denied the LSD outbreak had affected production of milk.
“I don’t have figures for all the states. But I have received some information from Gujarat, which shows that there is no decline in milk production,” he said.
He said the Centre has extended all help to the states and that he himself visited 5 states to discuss the LSD issue with officials.
Meanwhile, sources at the Ministry of Fisheries, Animal Husbandry and Dairying said the LSD outbreak affected 15.21 lakh cattle across the country till September 9, with most deaths – 69,000 – reported from Rajasthan. On September 7, the sources said, 37,600 new cases and 1500 deaths were reported.
With over 97 lakh vaccine doses administered so far, of the total cases, nearly 8 lakh cattle have recovered from LSD, they added.
Lumpy Skin Disease vaccine: Lumpi-ProVacInd, which could be commercially launched in a few months, is a homologous, live attenuated vaccine specifically targeted to protect cattle against the LSD virus.
The Indian Council of Agricultural Research (ICAR) is aiming to commercially launch in “four-five months” its indigenously-developed vaccine against the Lumpy Skin Disease (LSD) virus that has killed around 50,000 heads of cattle in several states since April.
Bhupendra Nath Tripathi, Deputy Director-General (Animal Sciences) of ICAR, said that Agrinnovate India, the commercialisation arm for products and technologies developed by ICAR institutes, had issued an expression of interest document for the vaccine, ‘Lumpi-ProVacInd’, last month, and that three companies had shown interest.
What is Lumpi-ProVacInd, and how does it work?
The vaccine, which has been jointly developed by ICAR’s National Research Centre on Equines (NRCE) at Hisar, Haryana and the Indian Veterinary Research Institute (IVRI) at Izatnagar, UP, is a live attenuated vaccine, similar to those used against tuberculosis, measles, mumps and rubella.
“It is also homologous, providing 100 per cent protection against LSD in cattle. Currently, we are only administering goat pox and sheep pox virus vaccines. These are heterologous vaccines offering only cross-protection (up to 60-70 per cent) for cattle against LSD, by virtue of all the three viruses belonging to the same capripoxvirus genus,” Tripathi explained to The Indian Express.
Inactivated virus vaccines, such as Bharat Biotech’s Covaxin that is being used to inoculate people against Covid-19, are less effective, with just 5-6 months efficacy against capripox viruses. Hence, the choice of a live attenuated vaccine for LSD.
How was the Lumpy Skin Disease vaccine developed?
Naveen Kumar, veterinary virologist and principal scientist at NRCE, said that the institute had collected skin nodule samples from LSD-infected cows near Ranchi in December 2019. The virus was isolated at the Hisar-based institute by early-January 2020. This was a period when cases of the disease were coming in from Odisha and eastern states. “These weren’t leading to any mortality. But being a virus totally new to India, we decided to work on it,” he said.
The next step was to propagate the isolated virus in African green monkey kidney (Vero) cells used in cultures. The culturing was done over 50 generations (“passages”) and took about 17 months. As the virus mutated after repeated passages, its virulence or disease-causing ability weakened. The pathogenicity loss started from around the 30th passage, although the mutated virus could induce the necessary immune response from its host.
“We did sequencing of the virus genome at the start and the 10th, 30th and 50th passages. The attenuated live virus was identified as a vaccine candidate after the 50th passage and tested on our laboratory mice and rabbits,” Kumar said.
In April this year, experimental trials of the vaccine candidate on the natural host (cattle) was undertaken at IVRI. These included 10 male calves that were administered the vaccine and five “control” animals that weren’t. After a month, both sets of calves were injected with the virulent virus. The control calves showed most of the LSD symptoms, whereas the vaccinated animals had developed full immunity.
Since July, field trials have also taken place, starting with 140-odd cattle (lactating and pregnant cows as well as calves, heifers and bulls) at a gaushala at Banswara in Rajasthan. The vaccine has also been administered to animals in 35 other gaushalas and dairy farms in Udaipur, Alwar and Jodhpur, besides Hisar and Hansi (Haryana) and Mathura (UP).
“We have not seen the disease in any of these animals, even while it has spread everywhere around them,” said Kumar.
So what exactly is the Lumpy Skin Disease virus and how prevalent is it?
LSD is caused by the lumpy skin disease virus (LSDV), which is a virus of the capripoxvirus genus in the poxviridae family. Sheeppox virus and goatpox virus are the other members of the genus capripoxvirus. The LSDV mainly infects cattle: cow and its progeny, and the Asian water buffalo.
According to a 2021 report of the United Nations Food and Agriculture Organisation (FAO), LSD outbreaks occur as epidemics several years apart. There is no known specific reservoir of the virus, and it is also not known where and how the virus survives between epidemics, the FAO report said.
The FAO report said that after being restricted for long to sub-Saharan Africa, the virus has spread to the Middle East and Turkey over the past decade. From 2015 onward, it has infected cattle in southeastern and Eastern Europe and in Russia.
LSD entered India, Bangladesh and China in July 2019. Since then, outbreaks of the disease have been reported from 20 Indian states and UTs, 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.
How does LSD spread, and what are the symptoms of the disease?
LSDV spreads through blood-sucking vectors like ticks, mites, and mosquitoes, and also through contaminated water, fodder, and feed. Mosquito and housefly infestations reach their peak during the monsoon, and veterinary scientists and government officers blamed the very wet July for the rapid spread of the infection this year especially in Gujarat, where the outbreak started.
Scientists have been advising that infected animals be isolated; however, the large numbers of stray cattle makes this task difficult, and has possibly been contributing to the rapid spread of the disease.
LSDV 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, Prof R M Patel, head of the department of medicine at the College of Veterinary Science and Animal Husbandry (CVSAS), Dantiwada, said.
The epidermis, the outer surface of the skin, gets separated from the dermis or inner layer, leading to the formation of lumps or nodules on an animal’s body. Fever, increased mucus secretion, and loss of appetite are among the other symptoms.
Autopsies carried out by Prof Patel’s team on eight carcasses in Kutch and Banaskantha found that the virus had caused necrotising vasculitis, or the death of tissues, and fibrosis in various organs of the infected cattle, leading to their death.
Also, the nodules may burst due to outer pressure or friction as the skin covering such nodules is very thin. The open wounds make the animals susceptible to secondary bacterial and protozoal infections, and maggot infestations can prove fatal.
And how bad is the current outbreak of Lumpy Skin Disease in India?
There were small outbreaks in Gujarat’s Kheda and Anand in 2020 and 2021, which the state animal husbandry department controlled by treating the infected cattle and giving goat pox vaccine to healthy animals in peripheral areas. But this year has been very different.
Since the first case was reported from Kaiyari, a village on the Indo-Pak border in Lakhpat taluka of Kutch, LSD has swept through the state, infecting cows of all breeds, and spread to at least 11 other states and Union Territories. Buffaloes have been largely safe.
According to official data, LSD has infected about 11.21 lakh cattle and caused 49,628 deaths across India as on August 31. The virus has been reported in Rajasthan (31 districts), Gujarat (26), Punjab (24), Haryana (22), Uttar Pradesh (21), Jammu & Kashmir (18), Himachal Pradesh (9), Madhya Pradesh (5), Uttarakhand (4), Maharashtra (3), Goa (1), and Andaman & Nicobar Islands (1).
Government officials said the actual numbers of both infections and deaths could be much higher — many dairy farmers and cattle herders may not be reporting cases, or they could be consulting private veterinarians.
