Landmark study uncovers lumpy skin disease details

Scientists have analysed and measured the risk of different insect species to transmitting lumpy skin disease virus (LSDV) for the first time.

LSDV, which causes severe disease in cattle, is rapidly emerging in new regions, spreading from Africa and the Middle East to cattle populations in Europe and Asia.

The research shows insects are unlikely to acquire the virus by biting infected cattle not displaying clinical signs, meaning such animals pose limited risk of transmitting the disease. This fills a critical knowledge gap and could change the design of control programmes for LSD outbreaks.

Findings

Findings published in the Journal of Virology reveal insects feeding on subclinical animals were 97% less likely to acquire LSDV than those feeding on clinically infected animals.

Stable flies (Stomoxys calcitrans) were the most efficient LDSV transmitters, followed by mosquitoes (Aedes aegypti). The study also demonstrated insects spread the virus through mechanical transmission, rather than it replicating in them.

Control policies

Beatriz Sanz‐Bernardo, lead author of the paper, said: “By combining the unique expertise and resources available at Pirbright, we were able to create models of transmission in unprecedented detail. The data we have obtained through studying transmission in live animal models and using mathematical modelling have answered crucial questions that can now deliver real world impact.”

Pip Beard, head of the large DNA viruses group at Pirbright, said: “The uncertainties surrounding the risk of LSDV transmission have hampered our ability to generate evidence-based control programmes that protect animal welfare and human livelihoods.

“The data we have compiled provides this vital knowledge, which authorities can now use to inform control policies. In particular, the discovery that preclinical and subclinical animals both pose a very limited risk of spreading disease supports LSD control programmes that target clinically affected cattle for rapid removal, rather than complete stamping out of all cattle in an affected herd.”