And arthritis of a somewhat different sort sometimes follows Lyme disease, an infection caused by Borrelia burgdorferi which is passed on by tick bites.

ECONOMIST: Bugged by disease

OspA is produced specifically by Borrelia burgdorferi, a bacteria that causes Lyme disease.

BBC: Test for tick disease

However, he said the majority of cases of Lyme disease in the UK were not caused by Borrelia burgdorferi, but by a separate species Borrelia garinii.

BBC: Test for tick disease