SECTION I.. Page

PAGE

GENERAL EPIDEMIOLOGIC CONSIDERATIONS 1

Historical 2

Clinical and epidemiologic identification 13

General characteristics of early epidemic outbreaks 14

Symptoms in former epidemics 19

Manner of spread 20

Human intercourse 23

Crowd gatherings 26

Mass attack 27

Healthy carriers and convalescents 30

General manner of spread in individual localities 31

Primary type of epidemic 31

Secondary type of epidemic 33

Mortality curves 36

Duration of explosive outbreak 37

Morbidity curves in 1920 recurrences 41

Spread in countries and continents 42

Spread in primary waves 42

Spread in recurrences 44