Influence of Age of Mice on the Susceptibility to Murine Schistosomiasis Infection

Intensity of human schistosomiasis infection increases with age, a peak being attained at early puberty. Hormones could be involved in the age-related changes in susceptibility to schistosomiasis. Male BALB/c mice were infected with Schistosoma mansoni either before or after puberty and worm numbers, cellular immune responses, hormonal levels and pathology analysed. Pre-puberty infected mice had a significantly higher number of adult worms (p<0.05), more severe granulomas, higher mortality rate and higher proliferative responses as compared to postpuberty infected mice. Levels of the hormones were lower in the pre-puberty infected mice as compared to the post-puberty group early in the infection. Plasma levels of testosterone and luteinizing hormones decreased significantly (p<0.05) in infected mice when compared to controls. Susceptibility to S. mansoni in male BALB/c mice seems to be influenced by levels of testosterone and leutenizing hormone at infection. Albeit, an infection with S. mansoni seems to lower the hormonal levels.