My late wife, on being diagnosed with arthritis in the mid-1990s, had it explained to her by the specialist at Falkirk Royal Infirmary that it was caused by being bitten by a tick, thereby contracting Lyme disease ("Scottish sufferer in Lyme disease Whitehall protest", The Herald, May 10 & Letters, May 11).

She was told the disease originated in the town of Lyme in Connecticut, US, and affected local deer hunters. Apart from arthritis, as it so unfortunately proved, it led to "other things" such as strokes. For my wife, the disease probably originated holidaying on Islay, despite both of us being covered up to deter bites.

John Macnab,

175, Grahamsdyke Street, Falkirk.