Duflocque describes how, on December 6, 1889, a lady returned from Paris, which was infected, to a village still free from the disease. She was taken ill on December 8; her coachman became ill on December 9; her child on December 11; its nurse on December 13; the chambermaid and a man servant on December 14; on the thirteenth a seamstress who had brought clothes into the house; then the father, mother, husband, and daughter of the seamstress. Within a further eight days influenza became disseminated throughout the whole village. .
Similar examples occur in large numbers in the literature of all countries, especially in the full official Swiss reports of F. Schmid.
Moreover, convincing observations regarding the dissemination of influenza by contagion are afforded by persons who winter on lonely mountain tops and passes. We know of no example-and one such example, proved with certainty, would be of the greatest significance for the aerodromal theory of influenza dissemination- where people, entirely removed from communication, or wintering upon mountain tops, were stricken with influenza. In every instance where such individuals had become affected personal communication with those ill with influenza in the valley could be demonstrated.
The significance of these instructive investigations, particularly those emanating from Switzerland, has been exaggerated by some contagionists.
It is going too far to deduce the non dissemination of influenza through the air from the fact that the isolated inhabitants on the mountains of Switzerland have not been attacked. It is quite conceivable that the germs of the disease which emanate exclusively from influenza patients are contained in the air of infected houses and cities, and that they also distribute themselves within certain limits through the air, without imagining that these germs can also be carried to mountain tops at an elevation of 2000 meters or more. Those who look upon influenza as a miasma of a vapor sinking down toward the earth from the air, have their views contradicted as much by the observations on mountain tops as by all the other facts regarding the dissemination of influenza.
If the mode of dissemination of influenza in Switzerland is studied in detail, it will be found to conform to the conditions of communication in that country. As far as the mountain passes are concerned, the routes traversed during the winter by the mail conveyances (Julier Pass, Great St. Bernard, Engadine, etc.) early showed numerous cases. The official Swiss report of F. Schmid contains an abundance of highly interesting details. We will quote some examples of the transportation of the disease to high altitudes:
A whole colony wintered on the Rigi (1800 meters). After the disease had been imported by a painter returning from Lucerne, most of the Rigi inhabitants were afflicted.
At the Grimsel Hospice (1375 meters), the watchman, returning from the valley where he had associated with influenza patients, was first taken ill. Two days thereafter the other watchman, who had not left the Hospice, contracted influenza.
In Arosa the physician was the first one to contract influenza immediately after his return from the infected Davos. In rapid succession the inmates of the physician's house became infected, and then those of other houses of Arosa.
In Davos the disease started from the Hotel Schweizerhof, where a recent guest was the first to become afflicted. Two persons who occupied the rooms adjacent to his next became ill, and finally there was a general infection of the whole locality.
The official report of the Austrian Chief Board of Health emphasizes the fact that only such inhabitants of mountainous altitudes as had associated with the infected inhabitants of the valley were infected by influenza.
A series of important facts proving the contagiousness of influenza is given by the observations on the dissemination of the disease upon ships and by means of maritime communication. From the enormous amount of material, and especially from that contained in the British marine report, the following conclusions may be drawn:
1. In those extra-European continents and islands which were infected by influenza the harbors and coast towns were first attacked by the epidemic. Frequently the ship importing the pestilence was identified.
2. Upon ships which, after voyages of weeks, touched at an infected port, there followed an outbreak of influenza a short time after the arrival at that port or a few days after leaving it. The following are but a few of the numerous examples:
Leith, the harbor of Edinburgh, and Hull in England were infected by ships' crews from Riga.
An American man of war brought influenza to Gibraltar, and a training ship conveyed it very early (December 15) to Spezia, which was one of the first places in Italy to be attacked. Already in the first week of January influenza was carried by a ship to the southern point of Africa, Cape Town.
At a time when influenza had not yet affected any harbor of the eastern coast of Africa, the French corvette "D'Estaing," severely infected with influenza, arrived in the middle of March at Zanzibar. On March 19 the commander of the French ship, still suffering from the sequelae of influenza, made his official visit to the "Sperber." Two days thereafter influenza broke out upon the "Sperber" and also upon land, among the employees of the East African Company who had been in communication with the "D'Estaing" and the "Sperber." The ship "Carola" arrived in Zanzibar from a healthy district and communicated with the infected "Sperber," with the result that on April 1 the disease also broke out on the "Carola."
Influenza broke out on the training ship "Bretagne," lying in the harbor of Brest, two days after an infected officer had returned on board. Of the 850 persons on the ship, 244 successively became infected. Later still another training ship, the "Borda," became attacked, while other ships lying in the neighborhood of the "Borda" and the "Bretagne," but having no communication with the latter, remained exempt. The officers of the infected ships, who on account of their illness were granted leave of absence home, carried the disease first to their families, and later on the whole city of Brest became infected. The mail steamer "St. Germain" left St. Nazaire on December 2, touched on December Sat Santander, and here received on board a traveler from Madrid, where influenza was prevalent, the crew of the ship, however, being in the best state of health. On the following day the traveler was taken ill with influenza; and four days later, the attending physician. Within two more days the disease spread with such rapidity throughout the whole vessel that out of the 436 passengers, 154 were taken ill, besides 47 sailors.