ArticlesA case-control study of measles vaccination and inflammatory bowel disease*
Introduction
The possibility that the inflammatory bowel diseases (IBDs)-ulcerative colitis and Crohn's disease-are caused by a transmissible agent such as a virus is an attractive hypothesis.1 Wakefield and colleagues have suggested that Crohn's disease might be the late result of measles virus infection at a critical time during early childhood. This “measles hypothesis” is based on a series of pathological and epidemiological studies.2, 3, 4
Wild-type measles infection is associated with substantial morbidity and mortality. In the developed world, complications occur in about one in 15 infections, and most deaths result from the development of pneumonia, acute encephalitis, or the rare but relentlessly progressive subacute sclerosing panencephalitis.5, 6 Live attenuated measles vaccine was introduced in the UK in 1968, and as a result of the vaccination campaign the incidence of measles infection and complications has fallen strikingly.5, 6
The measles hypothesis has been embellished with evidence from a cohort study suggesting an increased risk of IBD in individuals given live attenuated measles vaccine in early childhood.7 This report has led to concern about the safety of measles vaccination and resulted in some parents declining an effective vaccine. Counselling has been particularly difficult because the evidence on which to base reassurance on this issue is very limited.8
The present investigation was devised to assess the risk of IBD associated with vaccination against measles in early childhood. A case-control design was used because of the relative rarity of the disease and the frequency of vaccine exposure in the population.9, 10 The study focuses on the period between 1968 and 1991, during which measles vaccination was routinely offered and immunisation status documented in the UK by general practitioners (GPs) and community health services within the National Health Service. National uptake rates for measles vaccination ranged from 34% in 1968 to 90% in 1991.11
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Method
This case-control study was done in East Dorset, UK, with the approval of the local research ethics committee. 164 patients with a definite diagnosis of IBD on the basis of standard clinical criteria,12 and who were born in 1968 or later, were identified from hospital records. Two controls were selected randomly from the same GP list as each patient, and matched for sex and year of birth (to within 1 year either way).
Vaccination history of patients and controls before the age of 5 years was
Results
By the defined criteria, GP records provided an adequate childhood vaccination history in 118 (72%) patients, community health vaccination records yielded acceptable information in an additional 10 (6%), and patient/parental records were adequate in a further 12 (7%). Overall, records were inadequate in 24 (15%) patients, and these cases were excluded from analysis. Characteristics of the 140 patients considered to have an adequate vaccination record are shown in table 1. Reserves were
Discussion
The concept that IBD might be caused by a chronic viral infection is attractive, and fits with the observation that some viruses may produce a chronic and sometimes relapsing tissue-specific disease. The theory could also account for the apparent link between markers of childhood hygiene and the subsequent risk of developing IBD, in particular Crohn's disease.16 However, the evidence implicating wild-type measles infection as the cause of IBD2-4 is very controversial.17, 18, 19, 20, 21
A cohort
References (28)
- et al.
Perinatal measles infection and subsequent Crohn's disease
Lancet
(1994) - et al.
Crohn's disease after in utero measles virus exposure
Lancet
(1996) - et al.
Is measles vaccination a risk factor for inflammatory bowel disease?
Lancet
(1995) - et al.
Inflammatory bowel disease and domestic hygiene in infancy
Lancet
(1994) - et al.
Crohn's disease and measles
Lancet
(1997) - et al.
Measles virus and inflammatory bowel disease
Lancet
(1995) - et al.
Measles vaccination as a risk factor for inflammatory bowel disease
Lancet
(1995) - et al.
Crohn's disease, measles and measles vaccination: a case-control failure
Lancet
(1996) The aetiology of inflammatory bowel disease: the role of infectious agents
- et al.
Confirmation of persistent measles virus infection of intestinal tissue by immunogold electron microscopy
Gut
(1995)
Live measles vaccine: a 21 year follow up
BMJ
Measles virus and inflammatory bowel disease
Measles vaccination as a risk factor for inflammatory bowel disease
Lancet
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