Potentially deadly tick-borne parasite found in Scotland for the first time
It is believed to be the first time this organism, called Babesia venatorum, has been identified in animals in the UK - and the first time it has been found in sheep anywhere in the world.
Scientists warned that it indictaes a “a change in the landscape of tick-borne pathogens in the UK”. Tick-borne illnesses also include Lyme disease which has increased in recent years.
The parasite, which causes babesiosis - a malaria-like illness which can usually be treated if caught early - was found within sheep in the North of Scotland.
The research, by scientists at the University of Glasgow’s School of Veterinary Medicine and published in a journal today, said the parasite has been recorded extensively in the Far East including China and also in Europe with two confirmed human infections in Italy and warned that its presence in Scotland raises concerns for European public health and farming policy
The scientists believe that B. venatorum may have been carried by migratory birds coming to the UK from Scandinavia, where the parasite has previously been found in ticks collected from the environment and migratory birds.
Although some evidence suggests this parasite may be more virulent than the species of Babesia usually found in the UK, the risk of people contracting this infection is believed to be low.
Dr Willie Weir, senior university clinician in veterinary pathology, public health and disease Investigation, said: “The presence of B. venatorum in the UK represents a new risk to humans working, living, or hiking in areas with infected ticks and livestock, particularly sheep. Although we believe the threat to humans to be low, nevertheless local health and veterinary professionals will need to be aware of the disease if the health risk from tick-borne disease in the UK is to be fully understood.
“Our findings follow the recent report of the detection of tick-borne encephalitis virus in the UK. Taken together, these findings signify a change in the landscape of tick-borne pathogens in the UK, and the underlying causes for this need to be investigated.”
To conduct the study, scientists collected blood from sheep, cattle and deer in the northeast of Scotland, in areas where tick-borne diseases have previously been detected. DNA from the B. venatorum parasite was detected in the blood of a large number of sheep, which were not showing any signs of disease, and which were considered as carrier animals.
First author Dr Alex Gray said: “Our study reveals that sheep can be a natural host for B. venatorum in the UK, which is surprising since we believed roe deer to be the main mammalian host for this parasite in Europe.
“Given our findings, ongoing active surveillance of this parasite in UK livestock would be useful to fully understand the prevalence and transmission of the disease, as such information may be critical for controlling the spread of babesiosis. As sheep are routinely transported large distances, including across international borders, we would also suggest the role that livestock play in transmission of the B. venatorum parasite in continental Europe be re-assessed.”
The paper, ‘Discovery of sheep as a host species for zoonotic Babesia venatorum in the United Kingdom’ is published in the December edition of Emerging Infectious Disease. The work was funded by The Scottish Government’s Strategic Partnership for Animal Science Excellence.