Armstrong – Table of Contents

the country. Laboratory confirmation was not available; influenza virus was not
cultivated in animal hosts until 1933 (12). A retrospective history of individual illness in
the 1918 outbreak on the island served as the basis for suspicion of prior experience with
influenza. Control measures in 1918, such as restricting gatherings and group activities,
were not invoked in 1920 because of the loss of public health machinery occasioned by
an interim change in Ohio legislation (13) (Ohio Griswold Act). The attack rate in 1920
was higher than in 1918, possibly due to the lack of suggestions for restricting the
congregation of large groups during the epidemic.
The attack rate among the people on the island during the course of the 1920 epidemic
was 53.5 per cent – 369 persons affected among the population of 689 people. There
were two fatalities including the island’s only physician. In January communication with
the Ohio shore became more difficult. Formation of ice in early January hampered travel
by boat, and, later in the month, shore to island travel could occur only when the ice
thickened to support the weight of people and finally automobiles. The island was
effectively isolated except for occasional persons crossing the ice in late January and
February. Sporadic “typical” cases occurred in early January – on the 3rd and 12th. With
the appearance of illness in the patient on January 24, the epidemic exploded rapidly.
The authors found that the school was a major source for the dissemination of infection.
Influenza spread rapidly among the students who brought illness home to their families.
Graphs constructed by the authors showed a peak for the incidence of illness in the
students, followed by a second peak a few days later representing the incidence in non-
school attending family members. The incidence of illness in students decreased when
the school was finally shut down on January 30.