Sir, - Although I agree with most of what your Science Editor, Dick Ahlstrom, said in his article about tetanus (October 3rd), I beg to differ with him about the types of injury which put persons at risk of developing this disease.
When I was a medical student early in the last century, I saw a patient in hospital who developed mild tetanus from being scratched on the instep with a straw.
In one of the only two cases in my own practice during almost 60 years, there had not been any injury.
In my opinion, any breach of the skin, except from a clean kitchen tool or in an operating theatre, is potentially liable to result in lockjaw.
Ideally, every adult should maintain the immunity developed in infancy.
Dr Richard Brennan is quoted in the article as having said that "by and large" that immunity should protect indefinitely.
Immunity has to be renewed, as it does not last a lifetime. - Yours, etc.,
Seaghβn U∅ Conchubhair, Uarβn M≤r, Gallimh.