Insects and disease

Dr. Elkington said:—The subject upon which I have been asked to address you this evening is one which has, within the past six years, produced a profound alteration in several branches of science.<br>It is advisable, therefore, to clearly distinguish between the two methods in which insects play a part in spreading disease amongst human beings in relation to typhoid fever, whether (a) As carrying agents pure and simple, the infecting agent undergoing no change and not being dependent on the insect in any way.<br>(b) As hosts, intermediate or definitive, the infective organism being dependent upon the insect and undergoing an extracorporeal phase of development in its tissues.<br>Dr. Elkington believes that domestic flies are responsible for a large proportion of cases of disease, especially typhoid fever.