Man and Microbes. 93 



miningitis, which is a very fatal disease. At least four serious 

 outbreaks have been recorded. During the first period, 1805 

 to 1830, the disease was very prevalent in the United States. 

 The second period, 1837 to 1850, was marked by a serious epi- 

 demic in France. During the third period, 1854 to 1874, an 

 outbreak occurred in both the United States and France. The 

 fourth period began with 1875 and continued up until recent 

 years. There have been many serious epidemics in different 

 places during this period. Much credit is due Flexner and his 

 collaborators for an antimeningococci serum which has proved 

 to be efficacious in many cases in the treatment of the disease. 



In the early eighties a number of the most destructive bac- 

 teria were isolated. In 1880 the bacillus of typhoid fever was 

 discovered. This dreaded disease has doubtless claimed mil- 

 lions of victims in the past, and even to-day approximately 

 180,000 people in the United States annually suffer from the in- 

 fection. At least 18,000 die as a direct result of the disease. 

 We cannot even conjecture how many die or are impaired for 

 life from the indirect results of these minute engines of de- 

 struction. Typhoid fever and war have always been inex- 

 tricably associated. This fever was the chief source of our 

 fatality during the Spanish-American War. 



With the discovery and isolation of a specific microbe, many 

 phases of study must be devoted to it. Its resistance, growth 

 and methods of dissemination are some of the important as- 

 pects from which it is considered. We have learned so much 

 regarding the habits and habitats of the typhoid bacillus, and 

 ways of preventing contamination therefrom, that we may now 

 regard it, like smallpox, as an optional disease. We know that 

 it is strictly a human infectious organism, and that it confines 

 its chief destructive activities to the intestinal tract. It may 

 live for a long time in water and the damp earth. As it is 

 specifically a human disease, typhoid bacilli must always have 

 their origin from human excrement. It is a well-known fact 

 that one who has recovered from the disease may continue to 

 carry and disseminate typhoid bacilli for years afterward. 

 Man, running water and flies are some of the chief agencies of 

 dissemination. Infection can only occur through ingestion. 

 Water, milk, vegetables or prepared foods that have become 

 contaminated through the agencies of man or flies are the chief 

 sources by which infection occurs. To obviate all these sources 



