Published online by Cambridge University Press: 15 May 2009
Summarising our results, and considering their probable significance, we should draw the following conclusions.
Our observations do not suggest that the dissemination of a bacteriophage is likely to have been the cause of the sudden decrease in the excretion rate of B. aertrycke, which was observed among the population at risk during the epidemic previously recorded (Topley, Ayrton and Lewis, 1924).
Our results are completely at variance with those recorded by d'Herelle in the case of fowl typhoid, a disease which shows many points of similarity to enteric infection in mice. The observations we have recorded do not suggest that the presence of the bacteriophage will, in itself, prevent the epidemic spread of infection, check an epidemic when it has once started, or appreciably reduce the mortality among the population at risk. In the light of these results we cannot share d'Herelle's optimism as to the probable results of the wholesale administration of the lytic principle in a public water supply. We do not suggest that the Twort-d'Herelle phenomenon has no significance in the epidemic spread of disease, but it does not appear to us that the problem is the simple and straightforward one envisaged by d'Herelle.
The results of the last experiment of this series are in substantial agreement with d'Herelle's experiments on barbone in cattle, so far as they concern the action of the lytic filtrate in causing an immunising response, though we have not obtained such strikingly uniform and satisfactory results.
We would note, in conclusion, that we have not yet tested the effect of the administration of the lytic principle, by injection, during the course of an experimental epidemic.