Lentiviral Infections in Small Ruminants

Small ruminant lentiviruses (SRLVs), including maedi-visna virus in sheep and caprine arthritis encephalitis virus in goats, cause chronic, multisystemic diseases that undermine animal welfare and productivity worldwide. These retroviruses target cells of the monocyte/macrophage lineage, leading to slow-progressive pneumonia, mastitis, arthritis and, in severe cases, encephalitis. Transmission occurs primarily via respiratory secretions, milk and colostrum, as well as through prolonged close contact in mixed-species flocks. Viral genetic diversity and antigenic variation complicate diagnosis and hamper the development of effective vaccines. Control strategies centre on serological screening, culling of infected animals and management practices to limit vertical and horizontal spread. Recent advances in molecular diagnostics, host-genetic resistance markers and antiviral compounds have begun to reshape disease surveillance and offer new avenues for integrated control programmes in diverse production systems.

Research from Nature Portfolio

In vitro studies have demonstrated that ethanolic extracts of two Meliaceae species, Azadirachta indica and Melia azedarach, markedly reduce caprine lentivirus infectivity in goat colostrum and milk. Treatment with ethyl acetate fractions for up to 90 minutes led to viral titre reductions of up to 1,000-fold in colostrum and 800-fold in milk. These findings highlight the potential of plant-derived antivirals as adjuncts to existing control measures, offering a low-cost, locally sourced option to limit mother-to-offspring transmission of SRLVs in small-scale and resource-limited farming systems.

Lentiviral Infections in Small Ruminants publication trend

The graph below shows the total number of articles in lentiviral infections in small ruminants across all publications each year (not limited to Nature Index journals).

Technical terms

Lentivirus: A genus of retroviruses that establish persistent infections by integrating into the host genome and causing slow-progressive disease.

Small ruminant lentivirus (SRLV): Collective term for closely related viruses infecting sheep and goats, including maedi-visna virus and caprine arthritis encephalitis virus.

Capsid protein (p28): The structural protein forming the viral core shell, conserved among SRLVs and commonly targeted in diagnostic assays.

Epitope: A specific linear or conformational segment of a viral protein recognised by an antibody.

Enzyme-linked immunosorbent assay (ELISA): A serological test that uses antigen-antibody interactions and an enzyme-linked detection system to identify specific antibodies or antigens in a sample.

References

1. In vitro antiviral effect of ethanolic extracts from Azadirachta indica and Melia azedarach against goat lentivirus in colostrum and milk. Scientific Reports (2023).
2. Identification and characterization of linear epitopes of monoclonal antibodies against the capsid proteins of small ruminant lentiviruses. Frontiers in Microbiology (2024).
3. Circulation of small ruminant lentivirus in endangered goat and sheep breeds of Southern Italy. Heliyon (2024).
4. Differential gene expression and immune cell infiltration in maedi-visna virus-infected lung tissues. BMC Genomics (2024).