Lumpy skin disease (LSD) : Lumpy skin disease is an infectious viral disease of cattle, which often occurs in epizootic form. The disease is characterized by the eruption of nodules in the skin, which may cover the whole of the animal's body.
Lumpy skin disease (LSD) is an infectious disease in cattle caused by a virus of the family Poxviridae, also known as Neethling virus. The disease is characterized by fever, enlarged superficial lymph nodes and multiple nodules (measuring 2–5 centimetres (1–2 in) in diameter) on the skin and mucous membranes (including those of the respiratory and gastrointestinal tracts).Infected cattle also may develop edematous swelling in their limbs and exhibit lameness. The virus has important economic implications since affected animals tend to have permanent damage to their skin, lowering the commercial value of their hide. Additionally, the disease often results in chronic debility, reduced milk production, poor growth, infertility, abortion, and sometimes death. Onset of fever occurs almost one week after infection by the virus. This initial fever may exceed 41 °C (106 °F) and persist for one week.At this time, all of the superficial lymph nodes become enlarged.[2] The nodules, in which the disease is characterized by, appear seven to nineteen days after virus inoculation.Coinciding with the appearance of the nodules, discharge from the eyes and nose becomes mucopurulent. Lumpy skin disease is a viral infection of cattle. Originally found in Africa, it has also spread to countries in the Middle East, Asia, and eastern Europe. Clinical signs include fever, lacrimation, hypersalivation, and characteristic skin eruptions. Diagnosis is by histopathology, virus isolation, or PCR. Attenuated vaccines may help control outbreaks.
Lumpy skin disease is an infectious, eruptive, occasionally fatal disease of cattle characterized by nodules on the skin and other parts of the body. Secondary bacterial infection often aggravates the condition. Traditionally, lumpy skin disease is found in southern and eastern Africa, but in the 1970s it extended northwest through the continent into subSaharan west Africa. Since 2000, it has spread to several countries of the Middle East and in 2013 extended west into Turkey and several countries in the Balkans. More recently, outbreaks of lumpy skin disease were reported for the first time in Georgia, Russia, Bangladesh, and the People's Republic of China. The recent geographic spread of lumpy skin disease has caused international concern. The disease has not been recorded in the Western hemisphere or in Australia or New Zealand.
Infected cattle develop fever, lacrimation, nasal discharge, and hypersalivation, followed by the characteristic eruptions on the skin and other parts of the body in ~50% of susceptible cattle. The incubation period is 4–14 days. The nodules are well circumscribed, round, slightly raised, firm, and painful and involve the entire cutis and the mucosa of the GI, respiratory, and genital tracts. Nodules may develop on the muzzle and within the nasal and buccal mucous membranes. The skin nodules contain a firm, creamy-gray or yellow mass of tissue. Regional lymph nodes are swollen, and edema develops in the udder, brisket, and legs. Secondary infection sometimes occurs and causes extensive suppuration and sloughing; as a result, the animal may become extremely emaciated, and euthanasia may be warranted. In time, the nodules either regress, or necrosis of the skin results in hard, raised areas (“sit-fasts”) clearly separated from the surrounding skin. These areas slough to leave ulcers, which heal and scar.
Lumpy skin disease, ulcers
COURTESY OF DR. MAX BONNIWELL, OBAN, SCOTLAND.
Morbidity is 5%–50%; mortality is usually low. The greatest loss is due to reduced milk yield, loss of condition, and rejection or reduced value of the hide.
The nodular lesions involve the dermis and the epidermis, but may extend to the underlying subcutis or even to the muscle.[2] These lesions, occurring all over the body (but particularly on the head, neck, udder, scrotum, vulva and perineum), may be either well-circumscribed or they may coalesce.[2] Cutaneous lesions may be resolved rapidly or they may persist as hard lumps. The lesions can also become sequestrated, leaving deep ulcers filled with granulation tissue and often suppurating. At the initial onset of the nodules, they have a creamy grey to white color upon cut section, and may exude serum.[2] After about two weeks, a cone-shaped central core of necrotic material may appear within the nodules.[2] Additionally, the nodules on the mucous membranes of the eyes, nose, mouth, rectum, udder and genitalia quickly ulcerate, aiding in transmission of the virus. In mild cases of LSD, the clinical symptoms and lesions are often confused with Bovine Herpesvirus 2 (BHV-2), which is, in turn, referred to as pseudo-lumpy skin disease.[3] However, the lesions associated with BHV-2 infections are more superficial.[3] BHV-2 also has a shorter course and is more mild than LSD. Electron microscopy can be used to differentiate between the two infections.[3] BHV-2 is characterized by intranuclear inclusion bodies, as opposed to the intracytoplasmic inclusions characteristic of LSD.[3] It is important to note that isolation of BHV-2 or its detection in negatively-stained biopsy specimens is only possible approximately one week after the development of skin lesions.
Contents
Lumpy skin disease virus (LSDV) is double-stranded DNA virus. It is a member of the capripoxvirus genus of Poxviridae.Capripoxviruses (CaPVs) represent one of eight genera within the Chordopoxvirus (ChPV) subfamily.The capripoxvirus genus consists of LSDV, as well as sheeppox virus, and goatpox virus.[4] CaPV infections are usually host specific within specific geographic distributions even though they are serologically indistinguishable from one another. Brick-Like Structure Typical of Poxviridae VirusesLike other viruses in the Poxviridae family, capripoxviruses are brick-shaped. Capripoxvirus virions are different than orthopoxvirus virions in that they have a more oval profile, as well as larger lateral bodies. The average size of capripoxvirions is 320 nm by 260 nm.The virus has a 151-kbp genome, consisting of a central coding region which is bounded by identical 2.4 kbp-inverted terminal repeats and contains 156 genes.[4] There are 146 conserved genes when comparing LSDV with chordopoxviruses of other genera.[4] These genes encode proteins which are involved in transcription and mRNA biogenesis, nucleotide metabolism, DNA replication, protein processing, virion structure and assembly, and viral virulence and host range.[4] Within the central genomic region, LSDV genes share a high degree of collinearity and amino acid identity with the genes of other mammalian poxviruses.[4] Examples of viruses with similar amino acid identity include suipoxvirus, yatapoxvirus, and leporipoxvirus.[4] In terminal regions, however, collinearity is interrupted.[4] In these regions, poxvirus homologues are either absent or share a lower percentage of amino acid identity.[4] Most of these differences involve genes that are likely associated with viral virulence and host range.[4] 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 protein, which are found in other poxvirus genera.
Epidemiology
LSDV mainly affects cattle and zebus, but has also been seen in giraffes, water buffalo, and impalas. Fine-skinned Bos taurus cattle breeds such as Holstein-Friesian and Jersey are the most susceptible to the disease. Thick-skinned Bos indicus breeds including the Afrikaner and Afrikaner cross-breeds show less severe signs of the disease.This is probably due to the decreased susceptibility to ectoparasites that Bos indicus breeds exhibit relative to Bos taurus breeds.Young calves and cows at peak lactation show more severe clinical symptoms, but all age-groups are susceptible to the disease. Outbreaks of LSDV are associated with high temperature and high humidity It is usually more prevalent during the wet summer and autumn months, especially in low-lying areas or near bodies of water, however, outbreaks can also occur during the dry season.Blood-feeding insects such as mosquitos and flies act as mechanical vectors to spread the disease. A single species vector has not been identified. Instead, the virus has been isolated from Stomoxys, Biomyia fasciata, Tabanidae, Glossina, and Culicoides species.The particular role of each of these insects in the transmission of LSDV continues to be evaluated.[3] Outbreaks of lumpy skin disease tend to be sporadic since they are dependent upon animal movements, immune status and wind and rainfall patterns, which affect the vector populations.
The virus can be transmitted through blood, nasal discharge, lacrimal secretions, semen and saliva. The disease can also be transmitted through infected milk to suckling calves.[3] In experimentally infected cattle, LSDV was found in saliva 11 days after the development of fever, in semen after 22 days, and in skin nodules after 33 days. The virus is not found in urine or stool. Like other pox viruses, which are known to be highly resistant, LSDV can remain viable in infected tissue for more than 120 days.
There have been two different approaches to immunization against LSDV. In South Africa, the Neethling strain of the virus was first attenuated by 20 passages on the chorio-allantoic membranes of hens' eggs. Now the vaccine virus is propagated in cell culture. In Kenya, the vaccine produced from sheep or goatpox viruses has been shown to provide immunity in cattle.However, the level of attenuation required for safe use in sheep and goats is not sufficient for cattle. For this reason the sheeppox and goatpox vaccines are restricted to countries where sheeppox or goatpox is already endemic since the live vaccines could provide a source of infection for the susceptible sheep and goat populations.
In order to ensure adequate protection against LSDV, susceptible adult cattle should be vaccinated annually. Approximately, 50% of cattle develop swelling (10–20 millimetres (1⁄2–3⁄4 in) in diameter) at the site of inoculation.This swelling disappears within a few weeks. Upon inoculation, dairy cows may also exhibit a temporary decrease in milk production.
Natural immunity[edit]
Most cattle develop lifelong immunity after recovery from a natural infection.Additionally, calves of immune cows acquire maternal antibody and are resistant to clinical disease until about 6 months of age.To avoid interference with maternal antibodies, calves under 6 months of age whose dams were naturally infected or vaccinated should not vaccinated. On the other hand, calves born from susceptible cows are also susceptible and should be vaccinated.
History[edit]
Lumpy skin disease was first seen as an epidemic in Zambia in 1929. Initially, it was thought to be the result of either poisoning or a hypersensitivity to insect bites. Additional cases occurred between 1943 and 1945 in Botswana, Zimbabwe, and the Republic of South Africa. Approximately, 8 million cattle were affected in a panzootic infection in South Africa in 1949, causing enormous economic losses. LSD spread throughout Africa between the 1950s and 1980s, affecting cattle in Kenya, Sudan, Tanzania, Somalia, and Cameroon.
In 1989 there was an LSD outbreak in Israel. This outbreak was the first instance of LSD north of the Sahara desert and outside of the African continent.[2] This particular outbreak was thought to be the result of infected Stomoxys calcitrans being carried on wind from Ismailiya in Egypt. During a period of 37 days between August and September 1989, fourteen of the seventeen dairy herds in Peduyim became infected with LSD.[7] All of the cattle as well as small flocks of sheep and goats in the village were slaughtered.
Throughout the past decade, LSD occurrences have been reported in Middle Eastern, European, and west Asian regions.
Bangladesh
LSD was first reported to the Bangladesh Department of Livestock Services in July 2019.[8] Eventually 500,000 head are estimated to have been infected in this outbreak.[8] The United Nations Food and Agriculture Organization has recommended mass vaccination.[8] As a result of the introduction of fall armyworm and this cattle plague within a few months of each other, the FAO, the World Food Programme, Bangladesh Government officials, and others agreed to begin improving Bangladesh's livestock disease surveillance and emergency response capabilities.[8]
Pakistan
Main article: Lumpy skin disease outbreak in Karachi
India
In July 2022, the outbreak spread in 14 out of 33 districts of Gujarat state of India. By 25 July, more than 37000 cases and 1000 deaths in cattle were reported.
As of 1 August 2022, more than 25,000 cases were reported in Rajasthan in which more than 1200 bovines died.
Prevention
Control and prevention of lumpy skin disease relies on four tactics - movement control (quarantine), vaccination, slaughter campaigns and management strategies. Specific national control plans vary between countries and so advice should be sought from the relevant authorities and veterinarians.
Vaccination is the most effective means of control, and live homologous vaccines containing a Neethling-like strain of LSDV are recommended.
There is no treatment for the virus, so prevention by vaccination is the most effective means of control.
Secondary infections in the skin may be treated with Non-Steroidal Anti-Inflammatories (NSAIDs) and also antibiotics (topical +/- injectable) when appropriate.
Lumpy skin disease virus causes a severe disease in cattle characterised by nodules in the skin. Transmission of LSD occurs via insect vectors and vaccination is the most effective means of control. During the past five years lumpy skin disease has spread through the Middle East into southeast Europe, the Caucasus, southwest Russia and western Asia. The disease causes substantial losses in affected herds with significant economic consequences. It also blocks access of affected countries to lucrative export markets, compounding the financial impact of a LSD outbreak. The main lesson to be learnt from the current European LSD epidemic is to be vigilant of emerging diseases.
As per the Basic animal husbandry statics report - 2019, the total livestock population is 532.5 million in India1. In the Indian economy, livestock plays a key role. Approximately 20.5 million people rely on livestock1. The livestock sector accounts for 4.11% of GDP and 25.6% of GDP for agriculture1. One of the most critical constraints in such a condition is the spread of emerging diseases, which causes reduced milk production, meat production, draft capacity, dung, and hides. Lumpy skin disease (LSD) is an economically significant emerging viral disease of cattle and buffaloes. LSD, due to lower milk production, beef loss, and draught power loss, abortion, infertility, losses of the condition, and hide damage, causes significant financial losses2. LSD is associated with the Lumpy skin disease virus (LSDV), a member of the genus Capripoxvirus of
the Poxviridae 3. The LSDV has traditionally been limited to the African continent, but recently it had spread to different parts of the globe4. During this manuscript's design, LSD in India has spread to Kerala, Tamil Nadu, Andhra Pradesh, Telangana, Odisha, Jharkhand, West Bengal, Assam, Tripura, Chhattisgarh, Maharashtra, and Madhya Pradesh. No specific treatment for LSD could be available; only symptomatic treatment with allopathic antibiotics has been suggested 3,5,6. Drug resistance, high monetary involvement and other side effects of
allopathic antibiotics cannot be ignored. Again, several successful attempts have been recorded to reduce the symptom through ethno-veterinary practice, reducing livestock rearers' economic loss. Ethno-veterinary medication, the scientific concept for traditional animal diseases treatment, offers low-cost approaches to allopathic Medicines7. Hence, the essence of this paper is to review available ethno-veterinary practices for LSD
control on e-resources. The names of the plant have been provided as suggested by the respective authors.
