CLASSIFICATION BY ETIOLOGIC AGENT
80 percent of all acute
respiratory diseases in
Table 3-1. Classification of acute respiratory diseases
An entire unit or community can develop influenza within 24 to 72 hours
after exposure to a newly introduced virus to which the members are susceptible.
This point is starkly illustrated by the pandemics of 1889, 1918, and 1957-
-- In 1918, more than 20 million people died from influenza caused by
the so-called swine virus or one closely related to it.
-- The 1957-1958 pandemic of Asian influenza was much milder but
was pandemic in the full sense.
b. Influenza Today. Influenza now is an acute self-limiting disease of abrupt
onset, lasting from 1 to 6 days.
Recovery in otherwise healthy persons of military age may follow in from
5 to 7 days.
Death from influenza itself, or from pneumonia as a complication,
sometimes occurs in persons who are weakened or debilitated.