January 9, 1920] 



SCIENCE 



25 



water and by insect carriers have ceased to 

 figure as important factors in the death rate. 



As the aims of sanitation are approximately 

 realized in a given community, the attention 

 of the health official turns from the water- 

 borne and insect-borne diseases to the more 

 subtle and more baffling maladies that are 

 spread by direct contact from one individual 

 to another. As typhoid, cholera, plague and 

 typhus fever approach the vanishing point, 

 measles, pneumonia and influenza become 

 relatively more and more important. The 

 control of community infections tends to re- 

 place the sanitation of the environment in the 

 first rank of public health problems. The pre- 

 dominating tasks in this phase are tasks for 

 the bacteriologist rather than for the engineer. 



The leaders of the public health movement 

 in the United States fifteen years ago were 

 concerned primarily with problems of this 

 sort. Their interest lay in the detection of 

 incipient cases and of well carriers — those in- 

 dividuals who while in normal health them- 

 selves are cultivating and distributing from 

 their bodies the germs of specific commu- 

 nicable diseases — in isolation, in bedside dis- 

 infection, in the breaking by any possible 

 means of the vicious circle which transfers 

 the discharges of the infected individual to 

 the mouth or nose of the susceptible victim. 



In the case of certain of the acute com- 

 municable infections we are fortunately able 

 to invoke another weapon against our mi- 

 crobic enemies, by the prophylactic or thera- 

 peutic use of vaccines and immune sera, 

 and so far the production of artificial im- 

 munity against attacks of the microbes of dis- 

 ease has proved on the whole more effective 

 than our attempts at breaking the chain of 

 contagion by isolation and disinfection. 

 Smallpox, for example, has dwindled from the 

 position of the chief pestilence menacing the 

 human race to almost the condition of a med- 

 ical curiosity, solely and directly as a result 

 of the use of vaccine. Typhoid fever has been 

 practically eliminated from the army by an 

 analogous procedure. Antitoxic serum has 

 placed the control of diphtheria within our 

 grasp and diphtheria persists as a cause of 

 death simply because of the failure to recog- 



nize the disease with sufficient promptness 

 and to apply the protective measures at our 

 disposal. 



In general this second or bacteriological 

 phase of the public health movement, while 

 it can boast such remarkable achievements as 

 those to which reference has just been made, 

 is stiU far from the complete success which 

 has attended the applications of environmental 

 sanitation. It may be stated with some con- 

 fidence that there is not one of the diseases 

 originating in the non-living environment 

 which we do not know how to control and 

 which it is not entirely practical to control, 

 given adequate funds and personnel. Before 

 some of the contact-borne diseases on the 

 other hand we still stand almost helpless. We 

 may be able to reduce the death rate from 

 pneumonia by the use of protective vaccines, 

 but there has been as yet no actual victory won 

 sufficiently clear to admit of statistical dem- 

 onstration. We can do much to mitigate the 

 after effects of infant paralysis, but we have 

 no effective method of controlling its spread. 

 Before the ravages of a pandemic of influenza, 

 such as swept the world in 1918, we are still 

 practically without defense. Sanitarians have 

 been accustomed to quote with horror the fact 

 that bubonic plague killed 6,000,000 people in 

 India during a period of ten years. Influenza 

 carried off more than this number of persons 

 in India in the four autiunn months of 1918, 

 and if this should happen again next year we 

 should still be powerless to help. 



There is much then to be done in the fleld 

 of the community infections, many problems 

 yet to be solved by the bacteriologist and 

 serologist, before this group of diseases will 

 pass under our control. Yet the suppression 

 of community infections, like the sanitation of 

 the environment, is but a part of the broad 

 public health movement of the present day. 

 The task of the health officer is to save lives, 

 and to save as many lives as possible, by the 

 intelligent application of the resources placed 

 at his disposal. If he be wise he will direct 

 his energies and his appropriations according 

 to the indications derived from a study of 

 vital statistics. He will apply his resources 

 at a point where the greatest number of lives 



