“Soon after this we observed the disease in a Division, the 42d, then holding a part of the line in front of Baccarat. Here it had already developed a somewhat different nature, due, we believe, to the fact that the men of this Division were not, as were those at Chaumont, living in a rest area, but were actively engaged in military operations, working, sleeping, and eating under conditions that involved greater fatigue, less protection against weather, and greater crowding in sleeping quarters. The Baccarat cases were much more frequently catarrhal; sore throats, coughs and more serious respiratory complications were more common. However, they were usually coupled unmistakably with an underlying typical influenzal attack, sudden onset, pains and short lived fever. Moreover, there were a great many of the entirely uncomplicated cases interspersed with the others.
“Still later, in September, October and November, respiratory complications were so frequent and severe, came on so early in the disease, and the pneumonia mortality became so high, that the fundamental identity of these later cases with the early three-day fever might easily have been lost sight of by observers who had not followed the gradual transformation.
“In consideration of these facts, it is apparent that etiological or other investigations can throw no light upon the problems of influenza unless they are carried out with clearer understanding of the differentiation between the complications and the basic disease.
“The serious respiratory infections of the bronchi and lungs we can set down with reasonable certainty as complications due, certainly in the overwhelming majority of cases, to secondary bacterial invaders. It is a matter of considerable difficulty, however, to know exactly where the basic disease stops and the complications begin; and whether we must regard the mild sore throat and conjunctival injection which so often accompany the simple cases as a part of this basic clinical picture, or as the simplest variety of complication. This is much more than an academic question, since, as we shall see, the bacteriological analyses of such lesions have played an important role in etiological investigations.”
Symptoms in Former Epidemics.
The difficulty in making a decision in the presence of an epidemic is very similar to that of deciding whether the epidemics of former times were in each case influenza. Some few have been recorded in which the description has corresponded fairly well to that of primary uncomplicated influenza. Thus, concerning the epidemic of 1557 in Spain, Thomas Short wrote as follows: “At Mantua Carpentaria, three miles from Madrid, the epidemic began in August.... There it began with a roughness of the jaws, small cough, then a strong fever with a pain of the head, back, and legs. Some felt as though they were corded over the breast and had a weight at the stomach, all of which continued to the third day at furthest. Then the fever went off, with a sweat or bleeding at the nose. In some few, it turned to a pleurisy or fatal peripneumony.”
Most of the descriptions, however, have been of a general character and include descriptions of the complicated periods of the epidemic. One of the more complete of the early descriptions was that by Lobineau in 1414, who wrote: “C’était une espèce de rhume, qui causa un tel enrouement que les chastelets furent obligez d’interrompre leurs séances; on dormoit peu et l’on souffroit de grandes douleurs à la teste, aux reins et par tout le reste du corps; mais le mal ne fut mortel que pour les vieilles gens de toute condition.”
With this exception we possess no very good or complete description of influenza prior to the epidemic of 1510. After that time they have as a rule been detailed enough to enable identification. Hirsch bases his conclusions concerning the year 1173 chiefly on the following quotation: “Sub hisdem diebus universus orbus infectus ex aeris nebulosa corruptione, stomacho catarrhum causante generalem tussim, ad singulorum perniciem, ad mortem etiam plurimorum immissam vehementer expavite.” Nearly all that we have to go on in this description is the widespread incidence of the disease and the presence of respiratory symptoms, particularly cough. In 1323 the description emphasizes only the high morbidity. Thus, Pietro Buoninsegni writes: “In questo anno e d’Agosto fu un vento pestilenzia le per lo quale amalò di freddo e di febbre per alcuni dì quasi tutte le persone in Firenze e questo madesimo fu quais per tutta Italia.” The same author describes the epidemic of 1327, emphasizing again the high morbidity and in addition the low death rate: “In detto anno e mese fu quasi per tutto Italia corruzione di febbre per freddo; ma pochi ne morirono.” Again in 1387, he emphasizes the same two features.
Pasquier, in writing of the epidemic of 1403 in France, says: “En Registres de Parlement on trouve que le vingt-sixième jour d’avril 1403 y eut une maladie de teste et de toux, qui courut universellement si grande, que ce jour-là le Greffier ne pût rien enrégistrer et fut-on contraint d’abandonner le plaidoyé.” Here the high morbidity and the symptoms, particularly cough and pain, are emphasized. In 1414, Baliolanus describes again the high morbidity and symptoms, particularly cough and hoarseness: “Eoque frigore humanis corporibus concepto ... tussis maxima atque raucitas orta unde nullus pene ordo, aetas et sexus liber evasit.” In 1411, Pasquier writes the following: “En 1411 y eut une autre sorte de maladie dont une infinité de personnes furent touchez, par laquelle l’on perdoit le boire, le manger et le dormir ... toujours trembloit et avec le estoit si las et rompu que l’on ne l’osoit toucher en quelques parts. Sans qu’aucune personne en mourut.”
Subsequent to 1510 descriptions have been as a rule more definite. There are, however, exceptions to this statement and these fall in the epidemics concerning which there is some dispute.