"Certain sickness behaviors occur consistently in influenza-infected humans and mice. These include body temperature changes, somnolence, and anorexia..... Therefore virus-associated dsRNA detected by TLR3 appears to play a substantial role in mediating several aspects of the influenza syndrome in mice."
Majde, J. A., Kapás, L., Bohnet, S. G., De, A., and Krueger, J. M. (2009). Attenuation of the influenza virus sickness behavior in mice deficient in toll-like receptor 3. Brain, behavior, and immunity. http://www.citeulike.org/user/HEIRS/article/6048823
