Lumpy Skin Disease in Armenia

Lumpy skin disease is a poxvirus disease of economic importance. The first clinical cases of LSD in Armenia were registered in December 2015 among cattle which further was confirmed in laboratory in local and international levels. The source of LSDV was not identified and the role of vectors is not clear but there are some insects presented in country and which are known as a vector of LSDV transmission. For the control and prevention of the further spread of LSDV the vaccination with sheep pox live vaccine was conducted. During 2016 and first 9 months of 2017 in total 487518 cattle were vaccinated. In 2016 about 50% of total cattle population, which were located in risk zones, were vaccinated and in parallel with other control measures it have helped to stop further spread of LSDV in country.


Introduction
Lumpy skin disease (LSD, knopvelsiekte) is a pox disease of cattle caused by virus which is classified in the genus Capripoxvirus within the subfamily Chordopoxvirinae of the family Poxviridae [1] and characterized by fever, nodules on the skin, mucous membranes and internal organs, emaciation, enlarged lymph nodes, oedema of the skin, and sometimes death. The disease is of economic importance as it can cause a temporary reduction in milk production, temporary or permanent sterility in bulls, damage to hides and death due to secondary bacterial infections [2].
Lumpy skin disease is primarily a disease of cattle, but clinical cases have also been reported in Asian water buffalo (Bubalus bubalis).
Sheep and goats seem to be unaffected even when they are in close contact with cattle during outbreaks. The situation in wild ungulates is currently unclear [3].

Materials and Methods
Materials for LSDV antigen detection have been collected at postmortem from skin nodules, and lymph nodes of suspected being infected cattle. The diagnosis was performed by real-time PCR method based on protocol described in OIE Terrestrial Manual [2].
The live attenuated sheep pox vaccine was used (produces from RF) where sheep pox virus was cultivated on the tissues of testicles of lambs or in horioallantoisa of chicken embryos. The cattle above 6 months were vaccinated once hypodermically by x10 doze of vaccine.

Results
Up to 2015 the LSD was never registered in Armenia and first clinical cases of LSD was seen in southern part of Armenia (near border with Iran) in the end of 2015 among cattle which were kept in pastures. The samples which were taken from dead animals were positive for LSD in RT-PCR and additional diagnosis was done in Federal Governmental Budgetary Institution "Federal Centre for Animal Health" (Vladimir, Russian Federation) which confirmed the presence of LSDV.
More likely the LSDV was introduced in country from Iran or Turkey because only this two countries among neighboring countries previously had announced about LSD cases among livestock. The source of infection and way of transmission are not identi ied but it is known that LSDV is thought to be transmitted primarily by arthropod vectors, such as Mosquitoes, biting lies (e.g., Stomoxys calcitrans , Biomyia fasciata ), Culicoides midges and hard ticks (e.g., Amblyomma hebraeum , Rhipicephalus spp .) are currently thought to be mechanical vectors. Ticks probably play little or no role when LSDV is spreading rapidly during epizootics; however, they might be involved in transmission and maintenance in endemic regions. Prolonged virus survival has been reported in some vectors. Experimentally infected Aedes aegypti were infectious for 6 days, and transovarial and transstadial transmission were demonstrated in some species of ticks. Some lying arthropods, such as Culicoides , might introduce LSDV to new areas when they are carried by the wind [4,5].
Based on our investigations among above mentioned type of vectors which are able to transmit LSDV in Armenia are existing Mosquitoes, Stomoxys type of lies and Rhipicephalus spp . ticks which can be possible mechanical sources for disease transmission but not for long distances and only certain period of time when there are appropriate climate conditions. Anyway the irst case was registered during December in southern part of country and the temperature in this period of year is not enough for presence of above mentioned insects, so more likely disease was introduced through infected live animals or infected feed or other materials (Figures 1 and 2).
Since the LSD was registered in country first time and all cattle were intact for LSDV the infections among cattle were occurred with strong clinical signs and with mortality cases. In order to control further spreading of disease and control the situation was decided along with overall veterinary-sanitary measures (for example quarantine in Was taken account that only live attenuated vaccines against LSD are currently commercially available. Because of antigenic homology and cross-protection between sheep pox, goat pox and LSD viruses, any of these viruses can be used as a vaccine strain to protect cattle against LSD [4].
In OIE Terrestrial Manual described that all strains of Capripoxvirus examined so far, whether of bovine, ovine or caprine origin, share a major neutralizing site, so that animals recovered from infection with one strain are resistant to infection with any other strain. Consequently, it is possible to protect cattle against LSD using strains of Capripoxvirus derived from sheep or goats. In 1989 and 1990 the Romanian strain of sheep pox vaccine was used to help control the LSD outbreak in Egypt. However, it is essential to carry out controlled trials, particularly using the most susceptible breeds in peak lactation, prior to introducing a vaccine strain not usually used in cattle. The