610 BIOLOGY OF PNEUMOCOCCUS 



cent with positive cultures. With bacteriemia, the death rate is 

 thus about three to five times as great. The larger the number of 

 organisms per cubic centimeter of blood, the more unfavorable the 

 outlook. 



As shown in Figure 6, specific treatment lowers the death rate 

 in bacteriemic cases, in Type I infections from 64.6 to 31 per cent 



Figure 6 



type i and type ii cases with bacteriemia treated 



with serum and not treated with serum. 



number and percentage of deaths 



Type I Type II 



Treated with |||,||,|,,|||„„|| 31 . 0% WMMM ^.9% 



271 cases, 84 deaths 68 cases, 36 deaths 



155 cases, 100 deaths 227 cases, 173 deaths 



Note: Cases were collected from the literature. No cases from 

 the Massachusetts Pneumonia Study were included. 



and in Type II from 76.2 to 52.9 per cent. As shown in Figure 7, 

 when serum treatment is given within the first four days (ninety- 

 six hours) in Type I infections, the fatality rate is reduced to 

 26.2 per cent and in Type II to 54.2 per cent, the corresponding 

 fatality rate with early specific treatment and negative cultures 

 being respectively 5.2 per cent and 16.7 per cent. 



With respect to the possibility that selection may have modi- 

 fied the case fatality rates of reported series, it may be assumed 

 that exclusion of patients sensitive to horse serum from treated 

 groups and their inclusion in control groups did not of itself 

 modify the death rate. When the age has been averaged, it has 

 been found to be approximately the same in the treated and the 



