I caught polio at the age of six in an epidemic in Cork in 1956 and was taken to St Finbarr’s hospital in the city where I was well treated by the doctors and nurses. The fever passed but the virus had crippled the muscles of my back and legs so I was moved to another hospital nearby called St Mary’s at Gurranebraher, where the patients, mostly young children, were appallingly mistreated.

The nurses viewed the polio victims they were supposed to help as the irritating cause of them having to work and were angry when crippled patients asked for anything. I remember one nurse screaming at a small boy who had defecated in his bed because he was too weak to move and her saying that, if he did so again, he would be forced to eat his own excreta. I listened in terror and feared the same thing might happen to me.

The nurses maintained a rough barrack-room discipline, but I was bullied by older boys who smashed the toys brought by my parents. Years later I met Maureen O’Sullivan, a tireless volunteer nurse who drove a Red Cross ambulance during the epidemic, and she told me that the problem at the hospital was that “it lacked professional staff and there was a shortage of trained people. Many of the nurses looked at it just as a job and not a vocation. The main problem was always lack of resources.”

I stopped eating and speaking and my parents believed, almost certainly rightly, that I was dying. The doctors, who were a rather distant and ineffective presence in the hospital, believed that my deterioration was somehow connected with the polio. They noticed that the care of patients was poor, but they were told by the senior matron that she had great difficulty in recruiting nurses though untrained carers were easy enough to find

After 13 weeks at Gurranebraher, my parents brought me home where I rapidly recovered my spirits, though I was confined to a wheelchair.

A year later, I went to the Whitechapel hospital in London for an operation on the surviving muscles in my legs, which would enable me to walk again. I was surprised to find that many of the nurses in Whitechapel were Irish. In sharp contrast to what I had in Gurranebraher, they were kind, attentive and well trained.

The problem in Ireland in the 1950s was not so much a lack of nurses, but the fact that so many of the best of them had gone to Britain because of better pay, conditions and prospects. In coping with a rapidly spreading polio epidemic, the Irish health authorities had concentrated their best-trained and most experienced personnel to treat those who had just been diagnosed with the disease in St Finbarr’s, and had left the other hospitals to get by as best they could.

This problem has not gone away in the following 60 years. The British healthcare system remains extraordinarily reliant on attracting doctors and nurses from poorer parts of the world, notably Africa and South Asia, with damaging – and at time disastrous – consequences for the health of people in countries denuded of their best trained health workers.

“In the UK, over a third of the registered doctors are not originally from the UK and nearly half of nurses are from overseas,” says Rachel Jenkins, Professor Emeritus at the Institute of Psychiatry at King’s College, London, in an editorial in the journal International Psychiatry prefacing detailed papers on the brain drain of medical specialists from the poor to the rich.

Jenkins writes that – in a similar way to the polio epidemic in Ireland that I had experienced – “the dangers are exemplified by the recent outbreak of Ebola in West Africa, which was able to spread so rapidly because of weak health systems. Those systems would have been significantly stronger had it not been for health worker migration to the UK.”

The numbers involved are strikingly large. Out of a total of 255,141 doctors registered in the UK, no fewer than 82,866 or 36.4 per cent were trained elsewhere. Put simply, the UK population depends for its high standard of healthcare on health professionals trained elsewhere and the demand for which can only rise with the ageing of the British population.

The economic gain to Britain, and the proportionate loss to some of the poorest countries in the world, is very high. Jenkins points out that it costs £220,000 to train a doctor in the UK and £125,000 to train a nurse. If the training is done elsewhere, this implies a saving to the benefit of the UK of £65m from the employment of 293 Ghanaian doctors and £38m from the employment of 1,021 Ghanaian nurses, a sum that exceeds the annual UK aid to Ghana.

This unrecognised subsidy to Britain by poor countries has produced great dollops of hypocrisy about the recipients of aid. The Department for International Development (DFID) in the UK said in a report this summer that “our focus is on helping Ghana to end its reliance on aid and become a strong trading partner for the UK”.

NHS releases video showing impact of nursing in recruitment push

Solutions to the present toxic situation in which the poor subsidise the healthcare of the rich – and thereby deplete their own health systems – are twofold: wealthy countries like Britain should build up their own training of doctors and nurses to a level that meets demand. Poorer states, for their part, should improve pay and conditions for their own health professionals to the point that emigration ceases to be such an attractive option.

Such a change in British government policy is unlikely because the current deeply unfair system is, from its point of view, too good a deal. Jenkins argues that the situation will only change for the better “when rich countries assume some responsibility for reimbursing the country of origin for each foreign-born health worker”. This would give such countries the money to rebuild their healthcare systems.

Western states all benefit from siphoning off health professionals: some 23 per cent of the doctors in the US were trained abroad and 64 per cent come from low- or middle-income countries. This is not a statistic likely to be mentioned by President Trump as he denigrates immigrants in general as parasites taking jobs from native-born Americans.

The advocates of Brexit in Britain, conscious that opposition to immigration has been the core issue driving their success, have never wanted foreign health workers to be emblematic of immigration, perhaps conscious that a YouGov poll shows that 76 per cent of the British population welcomes them or would like more to come.