Our research raises many questions about whether measles virus has a role in bowel inflammation in developmental disorder

Professor John O'Leary

However, it published full details on its website on Tuesday after details were trailed in the BBC television programme Panorama.

Previous research by Dr Wakefield has linked the combined measles, mumps and rubella (MMR) vaccine to autism and bowel disorders.

Widespread concern

His theory has been disputed by the medical establishment, but has led to widespread concern among the public.

This has been blamed for a drop in uptake levels of the MMR, which experts fear will make outbreaks of measles more likely.

Public health experts are currently carrying out tests on 22 children suspected of having the disease in south London, and another four in Gateshead. Three cases of measles were confirmed last week in south London.

Dr Wakefield's new research does not look at the MMR vaccine, but the measles virus - a version of which is included in the vaccine.

The study set out to investigate whether children with developmental disorders such as autism and a bowel disorder also had the measles virus in their gut.

It found traces of the virus in the guts of 75 children out of 91 with bowel disease, but in only five out of 70 healthy children. More boys than girls were affected.

The researchers theorise that the virus may act as a trigger, leading to problems with the immune system.

The study does not look at whether the children were vaccinated with the MMR vaccine.

Don't jump to conclusions

An accompanying editorial advises against jumping to any hasty conclusions about MMR causing either bowel disease or developmental disorders such as autism.

The paper did not set out to investigate the role of MMR in developmental disorders or bowel disease, and no role for MMR is suggested in it

Molecular Pathology

The editorial concludes that there is evidence that developmental disorders are associated with some disturbance in the interaction between the brain and the gut, and that the study findings warrant attention.

But the authors say that several critical questions need to be answered before any potential link with MMR can be proved, including whether the measles virus was the same strain as that used in the vaccine.

Professor O'Leary, a molecular pathologist at Coombe Women's Hospital, Dublin, said: "I stand by the findings of our research, which raises many questions about whether measles virus has a role in bowel inflammation in developmental disorder.

"But the research did not set out to investigate the role of MMR in the development of either bowel disease or developmental disorder, and no conclusions about such a role could, or should be, drawn from our findings."

The editors of Molecular Pathology, Professor John Crocker and Dr David Burnett, said: "This paper was submitted by a scientist of international reputation, and accepted for publication after peer review.

"It was recognised by the referees and the editors as a potentially important observation which raised many questions about the possible role of measles in the aetiology of a syndrome in children.

"The paper did not set out to investigate the role of MMR in developmental disorders or bowel disease, and no role for MMR is suggested in it."