Sites of Persistence of Lumpy Skin Disease Virus in the Genital Tract of Experimentally Infected Bulls

Abstract

Two of the bulls developed severe lumpy skin disease (LSD) and were found to be shedding viral DNA in their semen on Day 28 p.i. Viral DNA was identified in all semen fractions from all bulls, but mostly from the cell-rich fraction and from the severely affected bulls. The PCR assay was positive on post mortem samples of testes and epididymides from the two severely affected bulls. Virus could be recovered from the testes of these two bulls and from the epididymis of one of them.Immunoperoxidase staining was observed in sections of testes and epididymides exhibiting necrosis.This study suggests that the testis and epididymis are the sites of persistence of LSDV in bulls shedding virus in semen for prolonged periods and revealed that viral DNA is present in all fractions of the ejaculate.

Evaluation of the safety, immunogenicity and efficacy of three capripoxvirus vaccine strains against lumpy skin disease virus

“…Previously it has been observed that only 40-50% of cattle experimentally infected with LSDV, are likely to develop generalized skin lesions. The remaining animals either show only a localized and circumscribed painful swelling at the inoculation site of LSD virus or show no clinical signs apart from mild fever [22][23][24]. This variation has also been reported to exist during mass vaccination against LSD [25].…”

Scientific Opinion on lumpy skin disease

“…A more recent study demonstrated the persistence of the live virus in bovine semen for up to 42 dpi and viral DNA was detected until 159 dpi (Irons et al, 2005). Using both PCR and virus isolation, the epididymis and testis were identified as the sites of persistence of LSDV, and viral DNA was detected in all fractions of semen (Annandale et al, 2010). Using both PCR and virus isolation, the epididymis and testis were identified as the sites of persistence of LSDV, and viral DNA was detected in all fractions of semen (Annandale et al, 2010).…”

Review: Lumpy Skin Disease: An Emerging Threat to Europe, the Middle East and Asia

“…However, successful transmission was achieved when naïve animals were allowed to share a drinking trough with severely infected animals (Haig, 1957). Transmission studies are further complicated by recent observations from experiments which demonstrated that, although only approximately 50% of infected animals are likely to show clinical signs, the majority of experimentally infected animals become viraemic (Weiss, 1968; Tuppurainen et al., 2005; Osuagwuh et al., 2007; Annandale et al., 2010). Molecular diagnostic tools such as PCR methods were not developed when these earlier transmission experiments were conducted, and thus, further studies using current diagnostic techniques are required to fully understand the complexity of the transmission mechanisms of LSDV.…”

“…In both studies, the virus was isolated from the semen of bulls with inapparent disease. Using both PCR and virus isolation, the epididymis and testis were identified as the sites of persistence of LSDV, and viral DNA was detected in all fractions of semen (Annandale et al., 2010). Vaccination of the bulls with the South African live attenuated Neethling strain prevented shedding of LSDV in the semen in animals challenged with LSDV after vaccination, and vaccinated animals did not shed vaccine virus in the semen (Osuagwuh et al., 2007).…”