668 PATHOGENIC MICROORGANISMS 



ing ten minutes. Chantemesse 74 has claimed that the opsonic index of 

 typhoid patients was increased after treatment with a serum obtained 

 by him from immunized horses, and Harrison 75 has reported similar 

 results in patients treated by a modification of Wright's method of 

 active immunization. Klein claims to have demonstrated that in 

 typhoid-immune rabbits, after five injections, the opsonic contents of 

 the blood were increased to an equal extent as the bactericidal sub- 

 stances. He concludes from this interesting observation that it may 

 well be that the opsonins are quite as important in typhoid immunity 

 as are the latter substances. 



For diagnostic purposes in typhoid fever the estimation of the opsonic 

 index, so far, has not been proven to be of great value. 



SANITARY CONSIDERATIONS IN TYPHOID FEVER 



Typhoid fever is a disease which has been constantly diminishing 

 in frequency in civilized countries during the last one hundred years, 

 but is still a very formidable cause of death rate and disability. The 

 morbidity rates and death rates for typhoid fever vary considerably 

 in different communities according to the extent to which sanitary 

 supervision of water supplies, garbage and sewage disposal, etc., have 

 been developed. In general, the United States has been considerably 

 behind most European communities. In a table given by Gay 76 a 

 comparison of mortality averages per 100,000 population, comparing 

 a group of over 31,000,000 people compiled from the statistics of the 

 33 largest European cities, with 21,000,000 people representing the pop- 

 ulations of 57 of the largest American cities, the European mortality 

 average was 6.5, and the American 19.59. In similar compilations 

 taken by Gay largely from the report of the New York State Depart- 

 ment of Health for 1914, it is shown that there has been a progressive 

 decrease since 1910, running parallel to increased attention to water 

 supplies and general sanitation. For more extensive figures on the 

 prevalence of typhoid fever the reader is referred to the above-mentioned 

 compilation of Gay. He states that in 1900 there were about 350,000 

 cases of typhoid fever in the United States as estimated by Whipple, who 

 at the same time calculates that the cost to the community of these 

 cases must have been approximately $212,000,000. Since, as we shall 

 see, it has been variously shown during the last ten years that typhoid 



74 Chantemesse, 14th Internal!. Cong, for Hyg., Berlin, 1907. 



75 Harrison, Jour. Royal Army Med. Corps, 8, 1907. 



V6 Gay, F. P., Typhoid Fever, Macmillan Company, New York, 1918. 



