Challenges in addressing community concerns regarding clusters of multiple sclerosis and potential environmental exposures.

Citizens living around hazardous waste sites in the USA have expressed concern to public health officials at the local, state and federal level about a perceived high prevalence of multiple sclerosis (MS) in their communities. Many believe the occurrence of the disease is directly linked to exposure to chemical agents from the nearby hazardous waste site. Although the public's concern regarding these clusters should be addressed, epidemiologists have long known that evaluating perceived clusters is rarely fruitful for identifying an etiologic agent. In order to adequately address concerns regarding clusters of MS, as well as examining the role of environmental exposures and genetic susceptibility in the causal mechanism of disease, several activities need to be conducted including characterizing the occurrence of disease, developing a standardized case definition and establishing partnerships to develop innovative research techniques. Only with collaboration across disciplines and lessons learned from past research will we be able to effectively guide research efforts directed at determining the etiology of this disease.