Changes in iron and transferrin levels and body temperature in experimental airborne legionellosis

Guinea pigs were infected with either 5 or 100 cfu of Legionella pneumophila by aerosol exposure. Between two and 10 days after infection, groups of animals were killed, and their lungs and spleen were removed and cultured quantitatively. L. pneumophila multiplied in the lungs and spread to the spleen; the organisms were cleared first from the spleen and then the lungs. Significant changes were demonstrated in serum iron and transferrin levels and body temperature. The body temperature correlated directly and the serum iron concentration correlated inversely with the number of L. pneumophila recovered from the lungs but not from the spleen. These data suggest that fever and iron may restrict the growth of L. pneumophila in vivo.