NOTE:  as part of the ongoing review of issues in immunisation the
following review appeared in the August, 1999 issue of Commun Dis Intell.

Measles-Mumps-Rubella immunisation,
autism and inflammatory bowel disease:
update
Janaki Amin and Melanie Wong,
National Centre for Immunisation Research and Surveillance of Vaccine Preventable Diseases,
Royal Alexandra Hospital for Children, Westmead, New South Wales
Commun Dis Intell,  1999 Aug, 23:8, 222

Early last year we reported (1) on a study by Wakefield and colleagues which suggested there may be an association between measles containing vaccine, inflammatory bowel disease (IBD) and autism.(2)   The evidence for either association was very weak (1) and the study was conducted on a highly selected group of subjects. Since then several epidemiological investigations have found no evidence for any association with autism and/or IBD.(5,6,7,8,9)   Also, specific virological assays in patients with IBD, the proposed aetiological link for autism after measles-mumps-rubella (MMR) vaccination, have not detected measles virus.(3,4) Following the publication of the Wakefield study (2) however, there has been a measurable decrease in the uptake of MMR in the United Kingdom (UK). (10) 

In June this year two further reports were published that provide no support for a causal link between measles vaccine and autism.(11,12)   The Working Party on MMR Vaccine of the UK's Committee on Safety of Medicine's study (11) evaluated the reports of autism, Crohn's disease, and similar disorders developing after MMR or MR vaccination, collected by a firm of solicitors. A systematic review of these cases lead the Working Party to conclude that the information available (which was of variable quality, subject to selection bias and lacked a control group) did not support the suggested causal association between measles vaccine and autism or Crohn's disease.

The second report, by Taylor et al., (12) is a population-based study that overcomes many of the limitations of the Working Party's study. Taylor's study investigated 498 children with autism born since 1979 in the North Thames Region. These children's measles vaccination status was determined from an independent register. The investigators found that:
• there was a steady increase in cases of autism
  over time, however there was no 'step-up' after
  the introduction of MMR in 1988:
• the age of diagnosis of children with autism was
   not dependent on when or if a child had been
   vaccinated;

•  vaccination coverage rates in cases did not differ significantly from that for the region as a whole:
   and
•  developmental regression was not clustered in the months after vaccination.

These results should alleviate concerns about the possibility of MMR causing autism or ISD and hopefully reassure parents and others as to the safety of MMR.

References

1 . Amin J, McIntyre PB, Heath TC. Measles vaccine, inflammatory bowel disease and pervasive developmental disorder: is there cause for concem? Comrnun Dis Intell 1998:22: 8-59.
2. Wakefield AJ, Murch SH, Anthony A et al. lleal-lymphoid- nodular hyperplasia, non-specific colitis, and pervasive developmental disorder in children. Lancet 1998;351:637-41.
3. Afzal MA, Minor PD, Begley J et al, Absence of measles-virus genome in inflammatory bowel disease. Lancet 1998;351:64M47.
4. Chadwick N, Bruce IJ, Schpelmann S, Pounder RE, Wakefield AJ. Measles virus DNA is not detected in inflammatory bowel disease using hybrid capture and reverse transcriptase followed by polymerase chain reaction J Med Virol 1998;55:305-11.
5. Giliberg C, Staffenburg S, Schaumann H. Is autism more common now than 10 years ago. Br J Psychiatry 1998; 158:403-9.
6. Wing L. Autism spectrum disorders: no evidence for or against an increase in prevalence. BMJ 1996:312:327-28
7. Payne C, Mason S. Autism, inflammatory bowel disease, and MMR vaccine. Lancet 1998;351:907.
8. Fornbonne E. Inflammatory bowel disease and autism. Lancetl998;351:955.
9. Peltola H, Patja A, Leinikki P Valle M, Davidkin I, Paunio M. No evidence for measles, mumps, and rubella vaccine-associated inflammatory bowel disease or autism in a 14-year prospective study. Lancet 1998;351:1327-28.
10. CDSC COVER/Korner: April to June 1998 Commun Dis Rep CDR Wkly 1998:8:345-46.
11. Medicines Commission Agency/Committee on Safety of Medicines. The safety of MMR vaccine Curr Probi Pharmacovigilancie 1999:25:9-1 0.
12. Taylor B, Miller E, Farrington CP et al. Autism and measles, mumps and rubella vaccine: no epidemiological evidence for a casual association. Lancet 1999:353 (9169):2026-29.
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