A method for measuring the retained dose in experiments on airborne infection

Abstract

When killed radioactive bacterial spores are inhaled by guinea-pigs and retained in the lung, it is found that the rate of loss up to 5 weeks later is sufficiently constant for the initial retention of a group of animals to be calculated from the measured retention at a later time (say 3 weeks after exposure). If, therefore, the inhaled cloud contained also a pathogen, in known proportion to the spores, the initial retention of the pathogen could be calculated. The experiments apply to groups of animals, but it is believed that the conclusions are valid also for single animals. In experiments withBr. suisit was found that the fate, as regards infection, of individual animals within a group exposed to a common dosage was not significantly related to the estimated retained dose, despite the wide variation of individual doses about the group mean.