CONTENTS. 
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Page. 
Introduction 5 
Diagnosis ^ 9 
Method of investigation 11 
Intensive study of special districts 13 
Imported cases 18 
Race 18 
Nationality 19 
Sex 19 
Ages ^ 20 
Length of residence in the District of Columbia 21 
Prevalence 22 
Relation of increased temperature to increased prevalence of typhoid fever. . . 29 
Flies 30 
Geographical distribution 32 
Case and death rates for calendar years 1908, 1907, and 1906 37 
Typhoid fever death rate of Washington as compared with that of other cities. . 39 
Parallelism in the typhoid death rates of Richmond, Va,, and Washington, D. C . 41 
Death rate in the District of Columbia since 1900 from several infectious diseases 
and all causes , 42 
Sanitary condition of residences 43 
Disposal of sewage 44 
Water 45 
Bacteriologic examination of Potomac water .* 46 
Relation of typhoid fever to Potomac River water 98 
Milk 100 
Ice cream 108 
Raw shellfish 108 
Occupation 109 
Infection by contact 110 
Bacillus carriers 113 
Newcomers 150 
Servants 150 
Two or more cases in one house 152 
Prophylaxis 152 
Summary 154 
( 3 ) 
