318 Microbes and You 



on incoming ships to susceptible individuals on shore. A period 

 of forty days was established as a safe interval during which any 

 infected persons on shipboard would come down with clinical 

 symptoms of any diseases harbored on the ship. The United 

 States still devotes considerable time and effort to minimize chances 

 for diseases to be spread from persons arriving in the country by 

 land, sea, or air. While our technics are quite different from those 

 employed five centuries ago, the results have justified the effort. 



Persons suffering from some of the more serious contagious dis- 

 eases, including diphtheria and scarlet fever, are usually cared 

 for in isolation wards of our modern hospitals, and every precau- 

 tion must be exercised to control the spread of the infectious agents 

 to other patients and to hospital personnel. The body discharges 

 of such patients must be handled in a special way to insure that 

 they do not serve as a source of material for other infections. 



Not too many years ago hospitals caring for patients suffering 

 from contagious diseases were located on the outskirts of cities to 

 minimize the chance for microbes to find their way from the sick 

 rooms to the healthy people of the city. While this may have 

 seemed a reasonable measure in the early days of microbiology, 

 we know that such precautions about locating hospitals are un- 

 warranted, and hospitals today are placed where they can most 

 effectively serve the people in the community. 



USE OF DIAGNOSTIC TESTS 

 The Schick Test 



This reaction is based upon the intraj)ermal (into the skin) 

 injection of a carefully measured amount of diphtheria toxin into 

 the forearm of individuals to test their susceptibility to diphtheria. 

 The test was devised in 1913 by Bela Schick. If the person is 

 immune to diphtheria, he has sufficient antitoxin circulating in his 

 blood stream to neutralize the small amount of injected toxin. 

 Lacking such antitoxin, a person exhibits a reddened, swollen, 

 inflammator)^ reaction called a positive Schick Test, and such a 

 response indicates susceptibility to the disease. 



