Molecular and histopathological detection of lumpy skin disease in Buffaloes, Iraq

Abstract

The study aim is to confirm infection of Iraqi buffaloes with the lumpy skin disease virus (LSDV) using of molecular conventional polymerase chain reaction (PCR) and histopathology. Totally, 150 buffaloes of different ages and sexes at three Iraqi provinces (Wasit, Dhi-Qar and Maysan) were subjected for collection of 5 ml blood samples and for clinical examination for detection of skin lesions and collection of tick samples during 2021 to March 2022. The total positive results for conventional PCR examination of 150 buffaloes was 8 (5.33%) using the blood samples. Among totally 13 suspected LSD skin lesions, only 1 (7.69%) sample was found to be positive. Among 29 tick samples collected from the 29 infested buffaloes, the findings revealed no positive samples in these samples. Histopathological analysis of nodular skin lesion showed that there were edema, hyperemia, acanthosis, severe hydropic degeneration, and hyperkeratosis in the epidermis; whereas in the dermis, there were mononuclear cell infiltration, inclusion bodies, and vasculitis. Conclusion: In Iraq, despite vaccination programs applied since the first outbreak in 2013, LSDV remains large in persistence and distribution among most areas of the country, resulting in apparent morbidities and mortalities.

Lumpy Skin Disease: A Systematic Review of Mode of Transmission, Risk of Emergence and Risk Entry Pathway

“…Ten articles reported LSDV infection, via antibodies, clinical signs and PCR, in animals other than cattle ( Table 3 ). Specifically, these animals were mainly free-ranging African buffaloes ( Syncerus caffer ) [ 62 , 63 ], which were classified as LSDV positive via serological test, and the Asian water buffalo [ 38 , 64 , 65 , 66 ]. Other reported African wild ruminant species with antibodies against Capripox viruses included an Arabian Oryx ( Oryx leucoryx ) in a wildlife reserve [ 67 ], southern elands ( Taurotragus oryx ) [ 69 ], Springboks ( Antidorcas marsupialis ) [ 69 ], Impalas ( Aepyceros melampus ) [ 69 ], and wildebeests ( Connachaetes gnou , C .…”

“…These number of studies included 20 experimental studies (i.e., in laboratory conditions) [ 8 , 9 , 10 , 11 , 12 , 13 , 14 , 15 , 16 , 17 , 18 , 19 , 20 , 21 , 22 , 23 , 24 , 25 , 26 , 27 ], six observational studies [ 11 , 12 , 13 , 14 , 15 , 59 , 79 ] and one systematic review that focused on the role of stable flies [ 92 ]. There were four studies [ 18 , 19 , 39 , 66 ] in which the primary objective was not sampling LSDV from vectors in the field, but they were part of the study and thus included in the results. The groups of vectors cited in the selected articles were: the stable fly Stomoxys calcitrans (N = 12), mosquitoes (N = 6), biting midges Culicoides spp.…”

“…Thirteen articles [ 18 , 19 , 20 , 21 , 22 , 23 , 24 , 25 , 26 , 27 , 66 , 79 , 83 ], all of them published from 2011 onwards, investigated the vectorial capacity of hard ticks to be vectors of LSDV. Only five studies [ 18 , 19 , 66 , 79 , 83 ] sampled ticks obtained from the field. The authors of one study sampled ticks (species not specified) from LSD infected buffaloes, but the virus was not detected [ 66 ].…”

“…Only five studies [ 18 , 19 , 66 , 79 , 83 ] sampled ticks obtained from the field. The authors of one study sampled ticks (species not specified) from LSD infected buffaloes, but the virus was not detected [ 66 ]. Within the frameworks of another field study that relied on the sampling of different vectors from an outbreak in Kazakhstan [ 79 ], authors isolated LSDV in four Dermacentor marginatus and nine Hyalomma asiaticum ticks.…”

“…LSDV is host-restricted, similarly to other viruses of the genus Capripoxvirus. Although diagnosis of LSDV was performed mostly by serological methods, of which the main limitation is the lack of distinction between all Capripoxviruses, it is safe to assume that besides cattle, the other affected species are African and Asian water buffaloes, and just a few additional wild ruminant species [ 62 , 63 , 64 , 65 , 66 , 67 , 68 , 69 , 70 ]. Buffaloes seem to be more resistant to the disease than domestic cattle as studies reported less seropositivity, although it should be considered that the number of tested samples which studies reported were usually small.…”