Lumpy skin disease (LSD) is a severe, systemic disease of cattle associated with the Neethling poxvirus, a capripoxvims. It has a close antigenic relationship to sheeppox and goatpox viruses which are also in the same genus. There appears to be a difference in virulence between strains.
Authors: Dr. M. Ali Tahir, Dr. Muhammad Muneeb, Dr. Muhammad Akram, Dr. Kashif Hussain, and Dr. Asghar Abbas
History
In May of 1988, Egypt saw its first LSD epidemic. The Egyptian veterinary officials were unable to pinpoint the exact source of the disease. In several sections of the nation, increased illness incidence was linked to higher insect population densities. The illness initially spreads outside of Africa into Israel in August 1989. From illness foci in Egypt, a wind-borne mechanism of transmission via the stable fly (Stomoxys calcitrans) was suspected.
LSD resurfaced in Egypt in 2006 after an apparent 17-year hiatus, having been brought into the nation by infected cattle imported from African Horn countries. Despite a comprehensive immunization program, the illness spreads shockingly quickly across the country. Cases of LSD were recorded in Israel again in June 2006, prompting Israeli officials to assume that LSDV had previously been spreading in other Middle Eastern nations.
Since 1990, LSD outbreaks have been recorded throughout the Middle East. LSD was found in Kuwait in 1991, Lebanon in 1993, Yemen in 1995, the United Arab Emirates in 2000, Bahrain in 2003, Israel in 2006–2007, and Oman in 2010. The existence of LSDV in Saudi Arabia (first reported in 1992) was never definitively established. The Middle East has become a major importer of live cattle, frozen beef, and animal feed from Europe, Asia, and Africa to feed a fast-rising population.
Economic importance:
Because of the high economic effect of an outbreak, the World Organization for Animal Health (OIE) classifies LSD as a notifiable disease. Because of the high fever generated by the viral infection and subsequent bacterial mastitis, the condition is more severe in cows nearing the end of their lactation and produces a dramatic decline in milk supply. Infertility in cows and bulls can be temporary or permanent.
The reduced growth rate in beef cattle may be caused by the emaciation of diseased animals and a convalescence duration of many months. Deep skin sores produce lasting scars on hides and lower their value.
The disease is classified as notifiable throughout the European Community (82/894/EEC, 89/162/EEC), and if an outbreak occurs, the regulation would mandate the slaughter of affected and in-contact animals, as well as the establishment of a 3-kilometer protection zone and a 10-kilometer surveillance zone around infected premises (Council directive 92/119/EEC). These farm-level limitations would last at least 28 days or until veterinary officials granted permission to lift them. A country must have three disease-free years to restore its official disease-free status, which emphasizes the economic impact of an epidemic. Capripoxviruses are categorized as possible agro- terrorism agents by the United States government. During epidemics in developing nations, the poorest small-scale farmers and rural people, whose livelihoods are entirely dependent on cattle, bear the brunt of the burden.
Clinical findings:
Lumpy skin disease (LSD) is a viral infection that causes an acute or insidious sickness in cattle (LSDV). The virus belongs to the Capripoxvirus genus, which belongs to the Chordopoxvirinae subfamily of the Poxviridae family. Several publications give detailed descriptions of the typical clinical symptoms. In the majority of cases, lachrymation and fever (40–41℃) are the first signs of infection, however, some instances are nonfebrile. Subscapular lymph nodes expand significantly. Skin nodules (1–5 cm in diameter) appear shortly after the beginning of fever, in different numbers, from a few to many lesions covering the whole animal.
Ulcerative lesions form in the mucous membranes of the ocular and oral/nasal canals in severely infected animals, causing profuse salivation, lachrymation, and nasal discharge. LSDV might be present in any of these secretions. Pox lesions can be seen in the pharynx, larynx, trachea, lungs, and gastrointestinal system. Pox lesions can be found on the surface of practically every organ after a postmortem examination of severe cases.
Prevention Strategies
There is no treatment for the LSD virus and prevention by vaccination is the only way to control it. There is no effective treatment against Lumpy Skin disease, only control by a preventive measure such as, firstly isolating the effective animal from the herd, secondly starting supportive treatment. The rest of the animals must be vaccinated. The disease is transmitted by bloodsucking insects like ticks and mosquitoes and can also prove fatal. Disinfect the whole farm with disinfectant chemicals like cypermethrin and KMnO4 etc a load of flies reduced. Animals with chronic conditions must be slaughtered to keep other animals safe from this disease. Quarantine restrictions have proved to be of limited use.
Administration of antibiotics to control secondary infection and good nursing care are recommended, but a large number of affected animals within a herd may preclude treatment. Secondary infections in the skin may be treated with Non-Steroidal Anti-Inflammatories (NSAIDs) and also antibiotics (topical +/- injectable) when appropriate. Control and prevention of lumpy skin disease rely 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 and Immunization
Vaccination is the most effective means of control, and live homologous vaccines containing a Neethling-like strain of LSDV are recommended. The local government had 30,000 vaccine doses in stock, which were immediately administered to cattle in Karachi in March 2022. The federal government urgently imported four million vaccine doses from Turkey for the rest of the province. Consequently, we vaccinated two million cows in several districts of Sindh in two weeks. A safe and effective vaccine has been produced by 60 passages of the virus through lamb kidney culture. It is administered to all animals over 6 months of age and is effective, but is associated with the considerable local reaction that may persist over 1 month and may predispose flystrike. Local response to the vaccine is usually correlated with good antibody response. A freeze-dried, living attenuated virus vaccine is also available. Vaccination of cattle with poxvirus, also attenuated by passage through tissue culture, is effective in preventing infection with the lumpy skin disease virus and is currently the most common method of protection. A small percentage of cattle develop granulomatous local reaction but there is no spread of the sheep pox to sheep running with the cattle vaccination of a herd at the start of an outbreak has limited efficacy as most animals will already be incubating the disease. Poor needle hygiene in these circumstances may spread the disease. Cattle vaccinated with recombinant Capripox -rinderpest vaccine are immune to experimental challenges with both viruses but for a different length of time with each agent. Coupled with vaccination of at-risk animals, is used when the disease gains access to a previously free country. The vaccine, which cost Sindh government Rs250 per dose, is administered free of cost. Since the vaccine from abroad is expensive, the Sindh government aims to develop its vaccine. Researchers from Dow Medical University Karachi have been provided with the necessary funding and are optimistic they can accomplish this in nine months
This diagram shows the outbreak of Lumpy skin disease in different areas of Punjab. The exact figure of affected animals has not measured up till now but, this disease has caused massive loss in Punjab.
Recent outbreaks in Pakistan
First observed in 1929 in Zambia, LSD is a viral infection that causes fever and multiple nodules on the skin and mucous membrane of animals. The disease initially reported from Jamshoro in November 2021, has now spread to more than 10 districts of Sindh affecting more than 20,000 cattle. Since then, 33,483 animals have been infected in the province while 339 have died. Meer Bukhsh, a cattle farmer based in the Thatta district of Pakistan, is devastated. His 20 cows – his livelihood – have been infected by the rare Lumpy Skin Disease (LSD). Bukhsh and his son Meeral Vaccine rollout for cattle
The Director-General for Livestock Pakistan, Dr. Nazir Hussain, says, “Since the vaccine from abroad is expensive, the Sindh government aims to develop its vaccine. Researchers from Dow Medical University Karachi have been provided with the necessary funding and are optimistic they can accomplish this in nine months now nothing about LSD before February 2022, when two of his cattle got infected and died within a month. The disease has so far been found in 20,250 animals in the province, including 15,100 in Karachi, 3,781 in Thatta, 149 in Hyderabad, 656 in Badin, 85 in Jamshoro, 121 in Khairpur, 91 in Sujawal, 64 in Matiari, 35 in Shaheed Benazirabad, 124 in Sanghar, 36 in Thana Bola Khan, four in Qambar-Shahdadkot and two each in two in Tando Muhammad Khan and Dadu. Karachi and Thatta were the epicenters of the disease where more than 90% of infections are being reported. The viral disease has relatively high mortality rates, dairy cattle in peak production especially cross bred and exotic ones are often the most severely affected with a marked decrease in milk production, abortions and in male cattle can result in loss of fertility for a lifetime. It is estimated that there are more than 9.88 million cows and 10.97 million buffaloes in Sindh, that need urgent attention for the prevention of the epidemic. The summary stated that since the disease is currently spreading to only cattle, it is assumed by the experts that 30% to 40% of the population of cattle may get affected. It’s estimated that five million dairy farmers and meat sellers are suffering from the economic fallout of the LSD outbreak. According to the Sindh livestock department, as of the end of April 2022, approximately 36,000 cattle have been infected with LSD. The one positive is a low mortality rate: only 300 cows have died.