Infections in childhood and adolescence in multiple sclerosis. A case-control study.

A case-control study on multiple sclerosis was conducted in Western Norway during the years 1986-1988. Included were 155 persons with multiple sclerosis and 200 controls, marginally matched according to age, sex and area of residence. The mean age at measles infection was for the cases 6.6 years and for the controls 5.7 years (p = 0.06). The cases had more frequently experienced bronchitis and/or pneumonia in the age group 11-15 years (OR = 3.20, 95% confidence interval 0.96-10.63). Tonsillectomies were reported more frequently by the cases. The odds ratio was especially high for those treated at age 0-6 years (OR = 3.44, 95% confidence interval 1.63-7.27). The results are consistent with the idea of MS as an age-dependent, host-immune response to infection during childhood or adolescence.