Plasmodium berghei: Resistance to infection in group and individually housed mice

Abstract

Female mice housed alone (A) or in groups of five (G) were infected with Plasmodium berghei 2 weeks after splenectomy or sham surgery. Intact (sham-operated) A mice died later than intact G mice, but splenectomized A and G mice died at the same rate. In Expermient II, spleen weights and resting plasma corticosterone concentrations of male A and G mice increased over the first 6 days of infection. G mice had heavier spleens than A mice, but housing did not affect corticosterone levels. In an experiment with female mice, housing conditions were reversed on the day of infection for some animals. Higher spleen weights were found in mice housed in groups after infection, regardless of preinfection conditions. As with the males, plasma corticosterone levels increased over the first week of infection.