Introduction
Lumpy skin disease (LSD) is a disease of cattle and water buffalo caused by a Capripox virus belong to Poxviridae Family. Morbidity rates vary between 10 to 20% with a 1-5% mortality rate. LSD was first identified in 1929 in Zambia and then spread to Egypt in 1988, still confined in Africa. Currently, LSD is endemic in most African countries. Since 2012 it has spread rapidly through the Middle East and southern and eastern Europe. In 2015, the disease appeared in Russia, Greece and Armenia (MCI report, 2020). Three countries in Asia have reported the first occurrence of the disease to OIE in 2019: Bangladesh (outbreak start date 14/07/2019), China (outbreak start date 03/08/2019) and India (outbreak start date 12/08/2019) (DLS, 2019). The first outbreak in Bangladesh was reported to the Department of Livestock Services (DLS) on 22/07/2019 (DLS, 2019). LSD is highly host-specific, causing disease in cattle only and it is not zoonotic.
Transmission and clinical signs
Lumpy skin disease is primarily spread between animals by biting insects (vector), such as mosquitoes and biting flies. Less commonly, the virus may be spread by direct contact to the skin lesions, saliva, nasal discharge, milk, or semen of infected animals. The incubation period of LSD is 4 to 28 days. It ranges from inapparent to severe disease. The clinical sign includes Fever (> 41°C), reduction in milk production, depression, anorexia and emaciation, rhinitis, conjunctivitis, excessive salivation and enlarged superficial lymph nodes.
Impact in Bangladesh:
LSD causes huge economic losses which include permanent hide damage, emaciation, reduced milk production, abortion, infertility, and death. The outbreak in Bangladesh is having a significant impact on the livelihoods of small-scale farmers, which make up most cattle owners in the country. The cost of providing supportive treatment for 2-3 months during the recovery period is unrealistic for many of these low-income families. According to DLS report (2019), a total of 553528 cattle were affected by LSD in 2019.
Control strategy
As a vector borne disease, LSD is almost impossible to control without vaccination. Vaccination is based on live vaccines.
Vaccination Strategies: Heterologous Vs Homologous approach
• Heterelogous vaccination is based on Sheep or Goat live vaccines. It induces an incomplete and weak protection
• Homologous strains (Neethling strain) confer a solid and durable immunity
Conclusion
Bangladesh government is taking active steps to monitor and control the outbreak with messaging through posters, leaflets and awareness raising events. Besides, it has been strengthening border enforcement to slow the influx of cattle from India. The government is also trying to prevent the disease by local goat pox vaccine with limited scale. Private sectors are now encouraged by government to introduce Neethling strain vaccine to prevent and control the disease in this country. ACI is now on the process of getting approval from government to introduce attenuated Neethling strain vaccine (BOVIVAX LSD) in Bangladesh from MCI company and this vaccine is produced under European GMP requirements and it is also registered in EU.
Writer
Dr.Md.A.Saleque
Chief Technical Advisor
ACI Animal Health
