Influenza

by Warren T. Vaughan

By the first of July, 1918, convalescent cases of influenza began to appear among members of the crews of transports and other vessels arriving in Boston from European ports. The number of such cases on each ship was usually not more than four or five, but Woodward records that in one or two instances between twenty and twenty-five individuals were sick on incoming vessels. None of these were seriously ill, none were sent to the hospital, and none died. The disease in this class of persons did not become severe until late August. Woodward has found on inquiry among practising physicians that typical cases of influenza were seen with notable frequency in private practice in the vicinity of Boston during the month of August, and that they had developed no serious complications, the only after effect being the marked prostration.

These mild preliminary cases failed to attract attention; first, because of their relative scarcity, and second because of their benign character. Public attention was first directed to the influenza in Boston by the apparently sudden appearance during the week ending August 28th of about fifty cases at the Naval Station at Commonwealth Pier. Within the next two weeks over 2,000 cases had occurred in the Naval forces of the First Naval District. One week later there was a similar sudden outbreak in the Aviation School and among the Naval Radio men at the Massachusetts Institute of Technology. The first death in Boston was reported on September 8th.

The peak of daily incidence in Boston occurred around the first of October. In the week ending October 5th a total of 1,214 deaths from influenza and pneumonia was reported, while by the third week of October this total had fallen to less than 600, and for the week ending November 9th was down to 47. Around November 15th the number of cases rather suddenly increased and this recurrent wave lasted for about ten days. By the 25th the rate was back to what it had been around the first of the same month. On or about December 1st the incidence again rose and continued increasing daily, to reach its peak in a severe recrudescence around December 31st.

There are conflicting reports concerning the date of first appearance of the epidemic at Camp Devens, Massachusetts. Woodward says that a sudden and very significant increase was reported during the third week in August in the number of cases of pneumonia occurring in the army cantonment at Camp Devens, seeming to justify the statement that an influenza epidemic may have started among the soldiers there even before it appeared in the naval forces. Soper, on the other hand, as well as Howard and Love in their official report, place the date of the first case at Devens as September 7th. Soper remarks: “The Devens epidemic is supposed to have commenced on September 7, 1918, in D Company, 42d Infantry. On that date a case of supposed meningitis was sent to the hospital from this company; on the following day twelve cases were sent for observation. These proved to be influenza. By the 16th thirty-seven cases had gone from the same company.” Howard and Love state, “The first authentic cases of virulent influenza of the great autumn pandemic among troops in the United States appeared on September 7, 1918, at Camp Devens, Mass.” These statements by Howard and Love do not eliminate the possibility of earlier and less virulent unrecognized cases. Wooley, who was camp epidemiologist, reports that influenza began at Camp Devens on the 8th of September, 1918. It reached its acme on the 16th, 17th and 18th of the month and then rapidly declined, almost completely vanishing about the middle of November. He makes no observation as to whether a mild form of the disease was or was not present in the camp in March and April preceding.

Influenza entered Massachusetts at Boston. Reeks reports that it entered Connecticut at New London, the cases coming primarily from the experimental station and from Fort Trumbull, where vessels from foreign ports had discharged patients. He believes that the disease was first introduced by ships arriving in New London from abroad and by men from the Boston Navy Yard, but numerous foci developed in a short period of time in various parts of the state. Many of these had appeared by the middle of September, and the source, according to Winslow and Rogers, was traced to military establishments, chiefly Camp Devens. In Wallingford, Willimantic, Hartland, Rockville and Danbury, all of which towns were attacked early in the epidemic, investigation showed that the disease developed in each case two or three days after visits of soldiers from Camp Devens. In Connecticut the epidemic spread, beginning at New London, chiefly from east to west, reaching its peak in the Eastern section around October 4th, in the central section October 15th, and in the Western part of the state around October 24th. Towns which had been infected early by visitors from military establishments reached the climax sooner than other towns nearby. In spreading from New London north and west the large cities of Connecticut were successively invaded, New Haven and Hartford reaching their crest about ten days later than New London, while Fairfield County did not reach its acme until later than New Haven.

In the cities along the New England coast we see then that the disease reached epidemic proportions early in September. By September 21st it had become epidemic in a wide area along the Atlantic coast extending from the Southern part of Maine to Virginia, as well as in a number of localities scattered over the entire country. By September 28th, areas adjacent to the centers in which the epidemic had already appeared were affected, suggesting radial movement from these centers. By that time the greater part of the New England States, the North Atlantic and Central States, and some of the Gulf and Pacific Coast States had become involved. By October 5th the pandemic had apparently reached all parts of the country with the exception of the more isolated rural districts and some areas in the Central States and Mountain States. Within an additional ten days even these areas, with the exception of the very remote rural districts, had been reached by the epidemic. Within four weeks the disease had become distributed to all sections of the country, and within six weeks from its first epidemic prevalence in Boston practically the entire country had been invaded.

Sydenstricker in a preliminary report remarks on the fact that the disease reached an epidemic stage in a number of localities in the central, northern, southern and western sections at about the same time as it did in the area along the northeastern coast. “The possibility is suggested, therefore, that sources of infection existed in at least some of the larger population centers, well distributed through the country, some time before the disease appeared as a nation-wide epidemic. The apparent radial spread of the epidemic from certain centers would seem to strengthen this hypothesis. It may also be noted that there is evidence, the collection of which has not yet been completed, pointing to the existence of cases of the disease in various centers, probably widely distributed, weeks before they were definitely recognized as influenza. The possibility that these foci themselves had a common focus is by no means excluded, of course, but there is as yet no conclusive evidence that would warrant the statement that the starting point of the epidemic was Boston or any specific locality.”

Dublin, from a study of the statistics of the Metropolitan Life Insurance Company, finds that the virulence of the influenza, as indicated by the mortality rate, was greatest along the Atlantic Coast and became progressively less as it progressed westward. There was one exception. The mortality was high in San Francisco, higher than in other western communities. Dublin believes that quite possibly there was a double infection in San Francisco in the fall of 1918, one coming from the East and of small caliber, while the other came either by way of the Panama Canal or perhaps from Asia. The evidence in favor of two ways is that Dublin finds that the peak of incidence in San Francisco and in some other places on the Pacific Coast occurred sometime in advance of the similar peak at points inland from the coast. This is not brought out in Pearl’s chart, and the latter finds when considering the peak of deaths that the peak for San Francisco was late. The peak in that city, in Oakland, California, and in Los Angeles, was reached on the week ending November 2d. Few cities had as late death peaks. Cleveland and Pittsburgh reached their peak in the same week, St. Paul, Minnesota in the week ending November 16th, and St. Louis, Milwaukee and Grand Rapids not until the week ending December 14th. In the case of Milwaukee and St. Louis these were the high peak dates but they were second peaks. In the former the first peak occurred October 26th and in the latter November 2d. In Grand Rapids the increase in mortality was clearcut by the middle of October, although the peak was not reached until the week ending December 14th. These statistics would indicate that San Francisco was attacked, as evidenced by increase in death reports, relatively late, and at about the time that would be necessary for the disease to be carried across the continent.

In an article by Ely, Lloyd, Hitchcock and Nickson it is said that influenza first appeared in the Puget Sound Navy Yard, near Seattle, on September 17, 1918, and that it was introduced by a draft of 987 sailors received from Philadelphia, a number of whom arrived ill, or came down within a few hours after reaching their destination. As a result, Seattle and the State of Washington were infected somewhat ahead of the other West Coast States. According to the record, influenza did not assume epidemic proportions in the State of Oregon for nearly a month after this Navy Yard epidemic.

With army camps and cantonments situated in nearly every section of the country it is difficult to follow the general direction of spread from camp to camp. During the period of the epidemic, troop movements were in general from West to East toward points of embarkation rather than in the reverse direction. This was in the opposite direction to that taken by the pandemic. Away from the coast there were, however, many movements of troops from camp to camp, in the redistribution of forces. That these troop movements were not discontinued during the epidemic is indicated by the report of Howard and Love: “The virulent type of influenza had spread rapidly from camp to camp, from the Atlantic seaboard to the South and West, due to the continual interchange of personnel from infected to non-infected camps. Such movements of troops at this time were recognized as dangerous and inadvisable, and prompt recommendations were made by the Medical Department that such movements be discontinued or greatly restricted, if compatible with military interests, which, of course, were at the time paramount. The War Department was unable to approve any marked restriction of movement of men from camp to camp at this time. One result of the free inter-communication of military personnel was that practically all military stations in the United States were in the throes of the epidemic at the same time.”