Debate on the link between MMR, bowel disease and autism continues to rage, but new evidence increasingly indicates that children who develop ‘pervasive developmental disorder’ - PDD, an umbrella term for a variety of disorders, including autism - may do so as a result of the measles vaccine.

The first evidence of this link came from the UK’s Andrew Wakefield who, in two small studies of children with PDD and gastrointestinal symptoms, found them to be many times more likely (93 per cent vs 11 per cent of controls) to have ileal lymphoid hyperplasia, a new form of inflammatory bowel disease (Lancet, 1998; 351: 637-41; Am J Gastroenterol, 2000; 95: 2285-95).

Wakefield’s most recent study used histological data from tissue microscopy to confirm the presence of persistent measles virus in children with ileal lymphoid hyperplasia (Mol Pathol, 2002; 55: 84-90). It was found that 75 of 91 patients with ileal lymphoid hyperplasia and enterocolitis were had measles virus in their intestinal tissue compared with five of the 70 control patients.

The authors concluded that the virus may act as an immunological trigger.

A recent commentary on all the evidence so far by Barbara Hendrickson and Jerrold Turner, from the Section of Pediatric Infectious Diseases and Department of Pathology, University of Chicago, shows that even conventional medics now believe the evidence for a link is becoming compelling (Lancet, 2002; 359: 2051-2).