The onset was sudden, in most instances being initiated with marked sensations of chilliness in 82 cases. Although a severe chill was probably relatively uncommon, 44 of these patients considered the symptom of sufficient severity to describe it as such. This was accompanied by extreme general malaise with severe aching pains throughout the whole body. Intense backache was complained of in 40 cases, headache in 54 cases. A varying degree of prostration, sometimes leading to complete collapse, was almost universal; 5 patients complained of extreme asthenia and 2 of marked dizziness. At time of admission to the hospital the face, neck and upper chest exhibited a uniform erythematous flush, never macular in appearance. The conjunctivæ were deeply injected, but lacrimation was not noticeable and a true exudative conjunctivitis was not encountered. Onset was accompanied by a sharp elevation of temperature ranging from 100° F. to 106° F., in most cases being between 102° F. and 105° F., at the time of admission. No constant type of temperature curve was maintained. Excluding the 15 cases in this group that developed pneumonia, the temperature was well sustained throughout the course of the disease in 46, irregular in 33, and definitely remittent in 6. The duration of the fever varied between one and seven days, the temperature having returned to normal in all but 19 of the 85 cases by the end of four days. The duration of fever was one day in 18 cases, two days in 12, three days in 19, four days in 17, five days in 10, six days in 4, and seven days in 5. Of the 4 cases with fever for six days, 2 had a fairly extensive bronchitis, 1 a laryngitis. Of the 5 cases with fever of seven days’ duration, 3 had signs of an extensive bronchitis, 2 of only a mild bronchitis.
The pulse was relatively slow in rate as compared with the degree of temperature elevation, running between 90 and 100 beats per minute in the large majority of cases. At the height of the disease it was full and easily compressed. No irregularities were noticed. With recovery it fell promptly to normal. The respiratory rate showed only moderate elevation, being between 20 and 26 in most cases. In a few instances a rate as high as 32 was recorded at time of admission to the hospital, but this promptly fell with rest in bed. A respiratory rate rising above 26 after the third or fourth day of the disease nearly always indicated a beginning pneumonia. With recovery the rate promptly fell to normal. Cyanosis did not occur in the absence of pneumonia.
Aside from the manifestations of a profound toxemia, influenza was preeminently characterized by symptoms of respiratory tract infection. The appearance of respiratory symptoms occurred at varying intervals after the onset of the disease, being well developed by the end of twenty-four hours in most cases. A progressive attack upon the mucous membranes of the respiratory tract was universal, beginning with coryza and pharyngitis and progressing to tracheitis or vice versa. Further extension of the infection to the bronchi, however, was by no means universal, 49 cases in the group studied recovering without developing evidence of bronchitis. Sore throat was rarely complained of, and laryngitis, possibly due to secondary infection, occurred only once. The progress of the infection was marked subjectively by sensations of irritation, stinging, and a feeling of tightness. A profuse, thin, mucoid exudate appeared; the pharyngeal walls and the soft palate showed a characteristic deep red granular appearance. The onset of tracheitis began with a sense of burning and tightness beneath the sternum accompanied by a harassing cough, at first nonproductive, later with the outpouring of an exudate becoming productive. The sputum varied in character between a scanty, thin, mucoid sputum and a profuse, frankly purulent sputum in cases subsequently developing an extensive bronchitis. Hemorrhage from the mucous membranes was common. Epistaxis occurred in 12 per cent of the cases and was often profuse. The sputum contained fresh blood in varying amounts in 24 per cent of the cases; 51 per cent of the cases developed signs of bronchitis. In 15 of these the bronchitis was mild, probably limited to the larger bronchi, physical examination showing only inconstant sibilant and musical râles. The sputum in these cases was neither profuse nor frankly purulent; 36 cases developed a fairly extensive purulent bronchitis as manifested by more or less diffusely scattered moist râles and by moderately copious mucopurulent or frankly purulent sputum. This bronchitis was not accompanied by an increase in the respiratory rate or by cyanosis unless pneumonia subsequently developed.
Gastrointestinal symptoms were insignificant: 8 patients complained of nausea early in the disease and 6 of them vomited. Diarrhea occurred in only 1 case, constipation being the rule. The spleen was palpable in 21 cases, but this is of doubtful significance, since nearly all the patients came from malarial regions. Jaundice was not noted. Aside from the profound depression, sometimes amounting to stupor, mental symptoms were not noted except in 1 case which showed a mild delirium.
Influenza, although per se a self-limited disease of short duration, frequently leads to the development of serious complications, the most important of which are pneumonia and purulent bronchitis with a varying degree of bronchiectasis. In the group of 100 cases of influenza studied, purulent bronchitis developed in 36 instances, pneumonia in 15; in 3 cases there was lobar pneumonia, in 12 bronchopneumonia. Further discussion of these complications is reserved for the sections dealing with them in detail. Other complications were relatively rare. Otitis media occurred in one case and frontal sinusitis in one. No fatalities were observed among cases of uncomplicated influenza, the deaths that occurred being invariably associated with a secondary pneumonia due in nearly all instances to secondary infection with pneumococci or hemolytic streptococci.
Purulent Bronchitis
It has been stated that a considerable number of cases of influenza developed a more or less extensive purulent bronchitis. This term is used as descriptive of a group of cases showing clinically evidence of a diffuse bronchitis as manifested by numerous medium and fine moist râles scattered throughout the chest and evidence of a definitely purulent inflammatory reaction as indicated by the expectoration of fairly copious amounts of mucopurulent or frankly purulent sputum. This condition is regarded as quite distinct, on the one hand, from the common type of mucoid bronchitis frequently associated with “common colds” and a fairly common feature of uncomplicated cases of influenza, in which physical examination of the chest reveals only transient sibilant and musical râles without evidence of extension to finer bronchi, and, on the other hand, from bronchopneumonia.
Bacteriology.—Thirteen cases of purulent bronchitis following influenza in none of which was there any evidence of pneumonia at the time cultures of the sputum were made nor later were subjected to careful bacteriologic study. Specimens of bronchial sputum were collected in sterile Petri dishes and selected portions thoroughly washed to remove surface contaminations before bacteriologic examinations were made. The results are shown in Table XIII.
| Table XIII | |||
|---|---|---|---|
| Bacteriology of the Sputum in Cases of Purulent Bronchitis Following Influenza | |||
| CASE | STAINED FILM OF SPUTUM | DIRECT CULTURE ON BLOOD AGAR PLATE | MOUSE INOCULATION |
| GJ | B. influenzæ + + + | B. influenzæ + + + + | B. influenzæ |
| Gram + diplococci + | Pneumococcus + | Pneumococcus (type undetermined) | |
| WAL | B. influenzæ + + | B. influenzæ + + + | |
| Gram + diplococci + + | Pneumococcus IV + + | ||
| TH | B. influenzæ + + + | B. influenzæ + + + + | |
| Gram + diplococci + + + | Pneumococcus IV + + | ||
| LH | B. influenzæ + | B. influenzæ + + | |
| Gram + diplococci + | Pneumococcus IV + + | ||
| FBD | Gram + diplococci + + + + | Pneumococcus IV + + + | Pneumococcus IV |
| B. influenzæ + | B. influenzæ | ||
| Wa | B. influenzæ + + | B. influenzæ + + | |
| Gram + diplococci + + | Pneumococcus IV + + | ||
| Sh | B. influenzæ + + + | B. influenzæ + + | |
| Gram + diplococci + + | Pneumococcus IV + + + | ||
| Wal | Gram + diplostrep + + + | S. viridans + + | |
| B. influenzæ + | B. influenzæ + + | ||
| CLF | B. influenzæ + + + + + | B. influenzæ | |
| Gram + diplococci + | Pneumococcus IV | ||
| NCC | B. influenzæ + + | B. influenzæ + + + | B. influenzæ |
| Gram − micrococcus + | M. catarrhalis + + | M. catarrhalis | |
| Gram + diplostrep. + | S. viridans + + | ||
| JCM | B. influenzæ + + + | B. influenzæ + + + + | B. influenzæ |
| Gram + streptococcus + | S. hemolyticus + | S. hemolyticus | |
| Gram − micrococcus + | M. catarrhalis + | Pneumococcus IV | |
| Gram + diplococcus + | |||
| Bl | B. influenzæ + | B. influenzæ | |
| Gram + diplococcus + | Pneumococcus IIa | ||
| Bu | B. influenzæ + + + + | B. influenzæ + + + | B. influenzæ |
| Gram + diplococcus + + + + | Pneumococcus IV + + + | Pneumococcus IV | |
From the data presented in Table XIII it is evident that a mixed infection existed in all cases. The results obtained by stained sputum films and by direct culture on blood agar plates are of special significance. B. influenzæ was present in all cases, being the predominant organism in 6 cases, abundantly present in others, and few in number in 2. Of other organisms the pneumococcus was most frequently found, occurring in 11 of the 13 cases, in all but 2 instances being present in considerable numbers. S. viridans was encountered twice, once in association with a Gram-negative micrococcus resembling M. catarrhalis culturally. S. hemolyticus was found once, together with M. catarrhalis and a few pneumococci, Type IV, coming through in the mouse only and of doubtful significance. The stained sputum films and direct cultures always showed these organisms present in sufficient abundance to indicate that they were present in the bronchial sputum and were not merely contaminants from the buccal mucosa.