212 
TYPHOID FEVER IN DISTRICT OF COLUMBIA. 
be subject to typhoid than of persons between 15 and 30 years, we 
should still expect (according to the theory) that the age period 
under 15 }^ears would necessarily present a greater proportion of the 
total number of typhoid patients than would the age group 15 to 30 
years. 
In respect to sex of patients . — Stiles & Garrison (1906a, 70) have 
shown that in cases collected from literature (1,543 males and 810 
females examined) the whipworm infection was 17.30 and 20.37 per 
cent, respectively. In their own work 2,311 males and 1,146 females 
examined at the laboratory showed 6.45 and 10.21 per cent infection, 
respectively, with whipworms. Thus from both the literature at 
large and the results of examinations at this laboratory (based upon 
patients at the Government and at the Connecticut hospitals) the 
infection with whipworms is more common among females than 
among males. 
Of the 200 cases of typhoid examined this summer for helmin- 
thiasis, 52.5 per cent were males and 47.5 per cent were females (see, 
however, paragraph as to summer population, p. 208). Of the total 
number of cases of Uphold (866) studied by the board, 588 cases (67.9 
per cent) were males and 278 cases (32.1 per cent) were females. 
Accordingly the relative number of infections of typhoid in males 
and females were not altogether in harmon}'" with the relative number 
of probable whipworm infections in males and females, as judged either 
from the literature at large or from our own examinations. 
In patients from the District of Columbia, however, Stiles & 
Garrison (1906a, 18) report a slightly higher rate of intestinal helmin- 
thiasis among males than among females (8.68 and 6.20 per 100 per- 
sons, respectively), figures which are slightly more in harmony with 
the theory under discussion. 
In respect to race of patients . — Stiles & Garrison (1906a, 13) have 
shown that in the District of Columbia 746 whites and 378 negroes 
examined as to intestinal helminthiasis presented 4.96 and 12.43 
infections per hundred, respectively. The percentage of whipworm 
infection was 3.75 and 9.79, respectively. 
If whipworms bear any necessary or common relation to typhoid, 
we should therefore expect to find in the District a much higher 
typhoid rate per 1,000 inhabitants among the negroes than among 
the whites. Giving the theory any mathematical advantage it may 
derive from the change in the Washington population during the 
summer, it may be recalled (see p. 207) that the whites represent 
approximately 71 per cent, the negroes approximately 29 per cent, 
of our inhabitants. Assuming an equal exposure to infection (although 
this assumption gives the negro an advantage in the statistics) and 
an equal susceptibility to typhoid (a point which is still suh judice) 
