Host nutritional status and its effect on a viral pathogen

The nutritional status of the host has long been associated with both severity and suscep-tibility to infectious disease. The accepted model system proposes that inadequate nutrition impairs the functioning of the immune system, thus resulting in increased susceptibility to infection. However, current work suggests that not only can the nutritional status of the host affect the immune response, but it can also affect the viral pathogen. In a mouse model, a benign strain of coxsackievirus B3 became virulent and caused myocarditis in selenium- and vitamin E±de®cient mice. This change in pathogenicity was due to mutations in the viral genome, which changed an avirulent virus into a virulent one. Once these mutations occurred, even mice with normal nutriture developed disease from the mutated virus. These results suggest that the oxidative stress status of the host can have a profound in¯uence on a viral pathogen. Studies of the interaction between infectious disease and host nutritional status have generally shown that poor host nutrition leads to increased pathogenicity of the infecting agent. The increase in either susceptibility to or severity of infectious dis