228 BIOLOGY OF PNEUMOCOCCUS 



blood of practically all of forty pneumonia patients ; Strouse and 

 Clough (1910) 1347 reported positive results in 56 per cent of the 

 cases occurring in a localized epidemic in which the total mortal- 

 ity was only 20 per cent. Of cultures made by Lyall (1912), 840 

 40.5 per cent were positive, and if those taken at the time of crisis 

 or lysis, which were uniformly negative, are deducted, the figure 

 rises to 53 per cent. The fatality-rate for the whole series was 26.2 

 per cent, while that for the patients having pneumococci in the 

 blood was 50 per cent. The great prognostic value of blood cul- 

 tures in lobar pneumonia was early pointed out by Avery, Chicker- 

 ing, Cole and Dochez (1917), 36 who reported positive blood cul- 

 tures in 30.3 per cent of 448 cases. Of the positive cases, 55.8 per 

 cent were fatal, whereas only 8.3 per cent of patients with no pneu- 

 mococcemia died. The mortality among the patients harboring 

 strains of Types II and III and of Group IV in the blood was 

 above 50 per cent, and all cases in the series with Type III bac- 

 teriemia terminated fatally. 



In a study made by Sutton and Sevier 1365 at Johns Hopkins 

 Hospital in 1917 the numbers of deaths and of positive blood cul- 

 tures were practically identical. The series was so small (62) that 

 percentage figures are not of general significance. It was evident, 

 nevertheless, that of the cases observed, positive blood cultures and 

 deaths were far more frequent when the infecting Pneumococcus 

 belonged either to Type I or to atypical Type II. That some or- 

 ganisms of Group IV may be sufficiently invasive to enter the blood 

 stream is shown by the figure of 18.2 per cent of positive blood 

 cultures for cases in which a Group IV pneumococcus was the 

 causative organism. 



The correlation between mortality and bacteriemia did not hold 

 in the series reported by McClelland, 874 but pneumococci of Types 

 I and II were responsible for the majority of the positive blood 

 cultures and of the deaths. Here the fatality-rate for Group IV 

 cases was only 4.2 — the same as the percentage occurrence of bac- 

 teriemia. That pneumococcemia may be present in a large propor- 



