Influenza

by Warren T. Vaughan

The correctness of the foregoing description of the spread of influenza depends first, upon the accuracy of the authorities quoted, and particularly upon our having discovered the earliest report for each country. The author believes that the information as obtained for the United States represents nearly the true state of affairs, and that the error present is negligible. The information obtained for France is based upon the statements of excellent investigators, Netter, Chauffard and Massary, for the French population, and MacNeal, Zinsser and Longcope, for the American Expeditionary Forces. Here the statements agree both for the military and for the civil population that there was no widespread influenza in France much before April 1st. Also, the author feels that the information for England and Scotland is authoritative and will not later be changed. It is based particularly upon the excellent reports by Carnwath, who has investigated the subject in great detail. The excerpts from the German literature, although not abundant, are practically unanimous in agreeing as to the date of invasion in Germany. The reports from the remaining countries of Europe have been less abundant, and frequently the author has been forced to rely upon a report by only one individual; but while the date may be in error, yet the month of occurrence is probably correct.

For other continents, Asia, Africa and South America, the reports as far as they go appear reliable, but it is impossible to prove that at an earlier date there was not a very mild epidemic in some one of these localities, similar to the earlier epidemic in the United States, which escaped detection. It is particularly important, in view of the 1889 experience, that we obtain if possible fuller information on the earliest time of the appearance of the disease in China and other parts of Asia, and that we determine whether there was a spread from that continent to America previous to March, 1918.

Several factors have added considerably to the difficulty in tracing the site of origin of the 1918 epidemic and its direction of spread. The principal of these have been the speed of modern travel, the character of modern commerce, and the existence of a state of war. The channels of the commerce of today radiate nearly from all points to all other points of the civilized world. No longer are there a few preeminent lanes of travel, such as there were in 1580 when the epidemic spread clearly from Constantinople to Venice and on to Hungary and Germany, finally finding its way to Norway, Sweden, Denmark and Russia. The war has made it difficult to know accurately the date and direction of spread in enemy countries. We have practically no information, except that in the public press, from Russia and the Balkan States. By October of 1918 the severe form of the disease had become prevalent in every continent, and by December it had reached the farthest islands of the Southern Pacific ocean.

The apparent difference in the direction of spread between 1889 and 1918 makes comparison of rapidity difficult. But if we take as our starting point the time at which each epidemic became prevalent in commercial centers of Europe and the time at which it finally reached localities well off the usual paths of commerce we will see that there is some difference, the disease spreading more rapidly in the recent epidemic, but that the difference is no greater than could be accounted for by the more modern means of communication. From April, 1918, when the disease appeared in France, to October, when it was reported in Madagascar, is six months. From October, 1889, with the disease prevailing in Petrograd, to July, 1890, when it appeared in Madagascar, is nine months. It required seven months after the disease became epidemic in France this time for it to appear in Iceland, and nine months in 1889–90.

The earliest recorded epidemic of influenza in the United States in the spring of 1918 (but which was not recognized to be such until later) appears to have been that at Camp Funston, described by Opie and his associates as having appeared in that Camp March 5th. The epidemic swept quickly throughout the Camp and spent itself as rapidly. A second wave appeared in April and in May a third, both of which were almost entirely limited to newly drafted men brought into camp subsequent to the preceding outbreaks. Correlated with each of these three outbreaks was a period of increased incidence of pneumonia and bronchitis, frequently occurring in influenza cases. These complicating diseases were prevalent in the organizations attacked by the influenza and maintained the same relation to the length of service of the men affected.

The next report of influenza in the United States was from the Oglethorpe camps, beginning about March, 18, 1918. Within two weeks every organization in Camp Forrest and the Reserve Officers Training Camp was affected. After about three weeks the epidemic subsided rapidly. Fourteen hundred and sixty-eight cases were sent to the hospital out of a total strength of 28,586. It is estimated that 2,900 cases had occurred. The clinical symptomatology and the epidemic characteristics were described in detail.

On March 28th the author had occasion to observe a similar epidemic at Camp Sevier, South Carolina, which appears to have attacked a smaller proportion of the troops in camp, but which showed the same epidemiologic picture. A note in the Public Health Reports states that on March 30, 1918, the occurrence of eighteen cases of influenza, of severe type, from which three deaths resulted, was reported at Haskell, Kansas. This is the earliest report we have been able to find concerning the disease in civil communities. That for Chicago was practically contemporary. The Commissioner of Health of Chicago states in his special report on the autumn epidemic, that in March, 1918, distinct epidemics resembling influenza were observed in certain portions of that city.

According to Public Health Reports, fevers of an undetermined nature were reported during April and May at various points from Norfolk to Louisiana. “An examination of the records and reports of the physicians who had treated these cases leads to the belief that these fevers were mainly influenza of mild type.” It is possible, however, that all cases reported were not of the same disease, and in one locality in Louisiana dengue may have occurred.

Fleisher states that during the latter part of March and early part of April, 1918, there occurred at Camp Wadsworth an epidemic of measles and practically concomitant with it an epidemic form of bronchopneumonia associated with empyema. During this time there were some 200 cases of measles and twenty-one cases of bronchopneumonia or empyema in which a hemolytic streptococcus was the causative agent. He makes no mention of any epidemic of influenza either in mild or severe form, occurring at this period.

Forbes and Snyder reported that during the month of April, 1918, a highly contagious, but comparatively mild infection of the respiratory tract was epidemic in Camp Hancock. Several thousand men in the command were infected, but relatively few were ill enough to be sent to the hospital. The only fatal case occurred early in the epidemic, and it was the observations made in this case which prompted the study made by Forbes and Snyder.