Multiple sclerosis in India: A case-control study of environmental exposures

Objectives: To compare the rate of prior environmental exposures between Indian multiple sclerosis (MS) patients and controls in order to identify potential disease triggering factors. Material and methods: A standard self-administered questionnaire regarding prior exposures was presented to 56 Indian MS patients and 147 other neural disease and healthy controls at two large medical centers in India. Results: The rate of prior foreign travel, surgeries, blood transfusions, clinical chicken pox and mumps infections and exposure to cats and farm animals was not significantly different between MS patients and controls. However, clinical measles infection and dog exposure occurred significantly more often in the MS patients. Conclusion: These findings are consistent with but do not prove an association between prior measles infection, dog exposure and MS.