TICKS are more likely to carry the bacteria that can cause Lyme disease in areas where pheasants are released, new research has shown.
Pheasants are not native to the UK, but about 47 million are released here each year for recreational shooting.
Researchers studied ticks in 25 woodland areas in South West England where pheasants are released – and 25 nearby control sites where no pheasants are released.
They found that Borrelia spp. – the bacteria that can cause Lyme disease – was almost 2.5 times more common in ticks in the pheasant-release areas.
The research was carried out by the University of Exeter and the UK Health Security Agency. The findings were published in the academic journal ‘Ecology Letters’.
“Borrelia bacteria can live in a wide range of hosts, including pheasants, wild birds and mammals – and humans,” said Emile Michels, from the Centre for Ecology and Conservation on Exeter’s Penryn Campus in Cornwall.
“Pheasants are known to be ‘competent’ hosts of Borrelia – meaning they have a relatively high likelihood of contracting and retransmitting the bacteria.
“More research is needed, but our findings suggest there may be an increased risk of potential exposure to Borrelia-infected ticks for people – such as gamekeepers – who work in woodlands where pheasants are released in numbers,” Emile added.
Dr Barbara Tschirren, also from the University of Exeter, said: ‘Our findings are evidence of ‘spillback’ – where non-native species increase the prevalence of native pathogens. This can be an important route for the emergence of zoonoses (diseases that animals can give to humans).’
Dr Jolyon Medlock, head of the Medical Entomology and Zoonoses Ecology team at UKHSA, said: ‘While we have observed an increase in the bacteria that can cause Lyme disease in ticks, we do not have data on the resulting impact on human health, including evidence of Lyme infection.