The importance of disease induced changes in mammalian body temperature to mosquito blood feeding.

Laboratory mice infected with rodent malaria (Plasmodium berghei or P. chabaudi) or St. Louis encephalitis virus (SLE) were not hyperthermic during the infection period. However, all infected animals displayed pathogen-specific periods of hypothermia. Hamsters infected with P. berghei were hyperthermic on day 7 postinfection (PI) but became hypothermic on day 8 PI and remained so until death, approximately 20 days PI. Body temperatures of mice infected with P. yoelii were not significantly different from those of uninfected control mice. Mosquitoes (Aedes aegypti, Anopheles stephensi and Culex quinquefasciatus) successfully engorged on restrained, uninfected mice, but were unable to engorge on unrestrained, uninfected mice due to the natural antimosquito behavior of the healthy rodents. Mosquitoes successfully engorged on unrestrained, malaria or SLE infected mice only during certain pathogen-specific periods of infection, but were able to engorge on all restrained, infected mice throughout the infection period regardless of the animal's body temperature. Daily activity patterns of malaria infected mice followed pathogen-specific profiles which closely conformed to the observed mosquito-engorgement profiles.