The epidemics occurring in Chicago the last winter and the preceding year differed from each other considerably in their effects upon the respiratory and digestive organs and the nervous system.
In 1890 the disease made its appearance about the first of January, but in 1891 not until nearly the first of March.
Persons of every class, all ages and either sex were attacked, but, as indicated by the observation of Dr. J. Suydam Knox, children suffered from it much less than adults; however, Dr. Charles Warrington Earle saw many cases in children whom he thought experienced the same symptoms as adults. From my own observation, it appears that children were much less frequently affected than those of more advanced years.
The exact period at which the influenza first showed itself cannot be determined. Four or five weeks preceding the actual beginning of the epidemic, many patients suffered from acute rhinitis
INGALS EF. THE EPIDEMICS OF INFLUENZA OF 1890 AND 1891 IN CHICAGO.Read at the Congress of American Physicians and Surgeons before the American Climatological Association, Washington, D. C., September, 1891.. JAMA. 1891;XVII(15):557-560. doi:10.1001/jama.1891.02410930021001j