SERUM TREATMENT OF LOBAR PNEUMONIA 607 



Type I serum treated* cases in the literature, 384 or 15.6 per cent 

 died, indicating the saving of many lives. The expected death rate 

 of 25 per cent can be still further reduced, as shown by the results 

 in the Massachusetts cases, when the treatment is begun within the 

 first four days (ninety-six hours) of the onset. Of 504 cases thus 

 treated with concentrated serum, only 56 or 11.1 per cent died 

 (Figure 2). The importance of time is further emphasized by the 

 figures shown in the accompanying table. Of 377 cases of Type I 

 pneumonia treated within the first three days, only 32 or 8.5 per 

 cent died. The death rate rises abruptly by the fourth day. Of the 

 127 cases treated on this day, 24 died, or 18.9 per cent. 



table I 



TYPE I CASES TREATED WITH SERUM. NUMBER AND PERCENTAGE 

 OF DEATHS BY DAY ON WHICH SERUM TREATMENT WAS BEGUN 



Note: Cases were taken from the Massachusetts Pneumonia Study. 



The fatality rate is, however, diminished when treatment is be- 

 gun still later in the illness, but less strikingly than in the earlier 

 period. 



Similarly, Heffron has collected from the literature 992 Type 

 II cases treated without serum in the United States and Canada, 

 with 407 deaths, a fatality rate of 41.0 per cent (Figure 3). By 

 contrast, he finds 670 antiserum treated* Type II infections in the 

 literature with 205 deaths, or 30.6 per cent. Of 136 such cases in 

 the Massachusetts series, treated with concentrated serum within 

 four days (ninety-six hours) of onset, 37 died, a fatality rate of 

 27.2 per cent (Figure 3). 



* With unconcentrated or concentrated serum in the United States or Canada. 



