Environmental factors related to multiple sclerosis in Indian population.

Background: Multiple sclerosis (MS) is less prevalent among Indians when compared to white populations. Genetic susceptibility remaining the same it is possible that environmental associations may have a role in determining disease prevalence.

Aims: To determine whether childhood infections, vaccination status, past infection with Helicobacter pylori (H.pylori), diet, socioeconomic and educational status were associated with MS.

Material And Methods: 139 patients and 278 matched control subjects were selected. A validated environmental exposure questionnaire was administered. Estimation of serum H.pylori IgG antibody was done by ELISA. Patients and controls were genotyped for HLA-DRB1*15:01.

Results: In our cohort a significant association was seen with measles (p < 0.007), vegetarian diet (p < 0.001, higher educational status (p < 0.0001) and urban living (p < 0.0001). An inverse relationship was seen with H.Pylori infection and MS (p < 0.001). Measles infection (OR 6.479, CI 1.21-34.668, p < 0.029) and high educational status (OR 3.088, CI 1.212-7.872, p < 0.018) were significant risk factors associated with MS. H.pylori infection was inversely related to MS (OR 0. 319, CI 0.144- 0.706, p < 0.005).

Conclusions: Environmental influences may be important in determining MS prevalence.