Med Hypotheses. 2004;63(1):59-61
Peter Sondergaard H, Theorell T.
Swedish National Institute for Psychosocial Factors and Health (IPM) and Department of Public Health Sciences, Karolinska Institute, P.O. Box 230, 171 77 Stockholm, Sweden.
Multiple sclerosis (MS) is a disease of unknown aetiology.
The finding of monoclonal antibodies in MS has been attributed to various infectious agents.
Nematodes, such as Toxocara species have not been explored as possible aetiologic agents of MS.
Some epidemiological studies have found an association between exposure to stress and household pets prior to the diagnosis of MS.
In a case known to the authors, slight malaise and eosinophilia in peripheral blood preceded the diagnosis of MS by one year in a middle-aged man who lived in rural surroundings with cats in the household.
The ubiquitary parasite Toxocara catis or canis is prevalent and serum antibodies are found regularly in populations examined.
It is able to develop into the larval stage in human beings.
The hypothesis presented here is that MS could be initiated by such infections in previously unexposed subjects under conditions of long-term stress.