Chapter IV: Section III: An Investigation of Influenza in Boston (winter of 1920.) 127

Diagnostic standards for the 1918 epidemic 134

Standards for 1920 134

Morbidity 137

Relation of sex to morbidity 143

Relation of sex to severity 145

Morbidity by age 145

Relationship of occupation to morbidity 150

Effect of race stock 155

Mortality 156

Mortality by sex 165

Relationship to age 167

Relationship of occupation 170

Density of population 170

Race stock and mortality 173

SECTION IV.
AN INTENSIVE STUDY OF THE SPREAD OF INFLUENZA IN SMALL GROUPS OF
CLOSELY ASSOCIATED INDIVIDUALS 175

Effect of overcrowding 179

Domestic cleanliness 187

Economic status 189

Distribution of the disease through the household 191

The first case in the family 194

Intimacy of family contact 197

Recurrent cases 198

SECTION V.
IMMUNITY 199

SECTION VI.
INFLUENZA AND OTHER DISEASES 212

Influenza and tuberculosis 212

Other infectious diseases 220

Encephalitis lethargica 222

SECTION VII.
COMPARISON OF INFLUENZA WITH OTHER EPIDEMIC DISEASES 224

Epizootics 224

Asiatic cholera 228

Epidemic meningitis 228

Plague 229

Measles 231

SECTION VIII.
THE PREVENTION AND CONTROL OF INFLUENZA 234

Anticipatory or preventive measures 236

Organization of health services 237

Palliative measures in the presence of an epidemic 239

Problems for the future. Constructive research 241

Bibliography 245

Footnote 1:

From the Department of Preventive Medicine and Hygiene, Harvard
Medical School, Boston, Mass.

INFLUENZA.

AN EPIDEMIOLOGIC STUDY.