Among 18 autopsies upon men who have died with pneumonia following measles there are pulmonary lesions representing almost every type of pneumonia which has been found in association with influenza. In most instances pneumonia made its appearance during the second week of measles and death occurred during the third week. Of 16 instances in which the record is definite, pneumonia had its onset during the first week of measles in 4 instances, during the second week in 11 instances, and in one instance (Autopsy 390) perhaps not referable to measles in the fifth week. The duration of pneumonia varied from three to thirty-two days; in 10 instances it did not exceed one week, in 5 instances it was between one and two weeks and in one instance, thirty-two days. When the duration of pneumonia exceeded ten days some evidence of chronic pulmonary disease was found at autopsy.

The same lack of correspondence between clinical diagnosis and pulmonary lesions noted with influenza was found following measles. In accordance with the prevailing opinion concerning the character of pneumonia following measles, the diagnosis of bronchopneumonia was made in 13 instances and in all of these cases bronchopneumonia was found at autopsy. The diagnosis of lobar pneumonia was made 5 times and was correct only once. Nevertheless, lobar pneumonia was present 4 times, but was recognized only once (Autopsy 486.) Failure to recognize lobar pneumonia, was doubtless due in part at least to its association with purulent bronchitis and peribronchiolar pneumonia (Table LXXI).

Changes in Bronchi.—The changes in the bronchi do not differ in character from those associated with pneumonia following influenza. Purulent bronchitis recognized at autopsy by the presence of mucopurulent material in the small bronchi was found in a much larger proportion of instances in this group of autopsies occurring in 13 of 18 instances (72.2 per cent), whereas it was present in only 55.6 per cent of autopsies on individuals with pneumonia following influenza. There was peribronchial hemorrhage recognizable on gross examination in 3 autopsies and microscopically in 3 additional instances.

Bronchiectasis was present in a considerable proportion of these autopsies, dilatation of bronchi being noted in 7, but it was usually moderately advanced and at times limited to the bases of the lungs. The short duration of respiratory disease perhaps explains the infrequency of advanced bronchiectasis. The incidence of the lesion is greater with measles (43.7 per cent) than with influenza (22.4 per cent).

Microscopic changes in the bronchi do not differ from those found after influenza. Evidence of acute inflammation, often hemorrhagic in character, is found within the lumen of the bronchus and in the tissues immediately in contact with the lumen. Not infrequently the epithelium is lost; there is superficial necrosis and deposition of fibrin upon the surface and within the tissue. In the deeper tissues of the bronchial wall there is infiltration with lymphoid and plasma cells, which in the larger bronchi is particularly advanced about the mucous glands of which the acini exhibit degenerative changes. With the onset of chronic changes new formation of fibrous tissue occurs in the wall of the bronchus and in the contiguous interalveolar walls. The lining epithelium often loses its columnar cells and assumes a squamous type.

Changes in the bronchi with bronchiectasis have been similar to those following influenza. Weakening of the wall permitting dilatation is brought about by necrosis extending outward from the lumen a varying distance into the bronchial wall and permitting the formation tears which diminish resistance to intrabronchial pressure.

Lobar Pneumonia.—Lobar pneumonia following measles occurred in 4 instances. Onset in these cases was on approximately the 9th, 10th, 11th, or 14th day of measles; the onset of bronchopneumonia bore a similar time relation to the onset of measles, the average interval being nine days. Hepatization with lobar pneumonia was in 1 instance red, in 3 instances gray, and in all save 1 instance the consolidation was firm and coarsely granular on section. In the exceptional instance the greater part of the right upper lobe was laxly consolidated and rather finely granular but the microscopic appearance was in all instances that of lobar pneumonia. Lobar pneumonia in 2 of these cases was associated with purulent bronchitis present in parts of the lung that had not undergone consolidation, whereas in the other 2 instances there were acute bronchitis and peribronchiolar pneumonia recognized by microscopic examination.

In one instance hepatization of the lung presented some noteworthy features.

Autopsy 450.—G. D., white, aged twenty-one, a farmer, resident of Arkansas, had been in military service twenty-nine days. Onset of illness began on October 2, nineteen days before death, and on admission on the same day the diagnosis of measles was made. Signs of pneumonia, regarded as bronchopneumonia, were recognized five days before death. Three days later there was otitis media and paracentesis was performed. On October 3 and 10 neither S. hemolyticus nor B. influenzÆ was found in the sputum; on October 17 and 20 S. hemolyticus was not found but B. influenzÆ was present.

Anatomic Diagnosis.—Acute lobar pneumonia with gray and red hepatization in right upper and lower lobes; edema and peribronchial hemorrhage in left lung.

The entire lower lobe of the right lung (Fig. 29) with the exception of a narrow air-containing zone in contact with basal surface is firmly consolidated. The greater part of the consolidated tissue is yellowish gray, firm and coarsely granular. The uppermost part of the consolidated tissue is softer than elsewhere as if it has undergone autolysis. The lowermost part of the consolidated tissue in a zone from 2.5 to 3.5 cm. in breadth is firmly consolidated but deep red. The bronchi contain stiff plugs of fibrin. In the upper lobe continuous with the consolidated part of the lower is a semicircular patch of yellowish gray consolidation. It overlies the line of the interlobular cleft at the site of a break in its continuity. Consolidation appears to have spread from the lower lobe into the upper at the site where the alveolar tissue of the two lobes is continuous but is absent from that part of the upper lobe separated from the lower by the interlobular cleft. This semicircular patch of yellowish gray consolidation is separated from air containing tissue of the upper lobe by a zone of red hepatization about 1 cm. in thickness.

Bacteriologic examination showed the presence of Pneumococcus IV in the blood of the heart; B. influenzÆ alone was obtained from the right lower lobe and B. influenzÆ and staphylococcus from the left main bronchus.

The distribution of lobar pneumonia in the foregoing autopsy indicates that it has spread like a wave from the upper part of the lower lobe (Fig. 32) penetrating into the upper where the alveolar tissue of the two lobes is in contact; gray hepatization is everywhere separated from air containing tissue by an advancing zone of red hepatization.

It may be assumed that lobar pneumonia was caused by Pneumococcus II atypical in 3 instances although it was recovered from the lungs only twice, for in the third instance (Autopsy 486) it was found in the bronchus and in the inflamed pleural cavity; pneumococci were doubtless previously present in the lung, but had disappeared at least from that part from which the culture was made. Pneumococcus IV was evidently the cause of pneumonia in 1 instance (Autopsy 450), for it was found in the blood of the heart although it was absent in the culture from the lung.

Little significance can be attributed to the observation that B. influenzÆ was present in pure culture in the lungs from Autopsies 450 and 486, for the presence of Pneumococci IV in the blood of the heart in Autopsy 450 and of Pneumococcus II atypical in the pleura in Autopsy 486 furnishes evidence in view of the occurrence of lobar pneumonia that pneumococci had disappeared from the lungs. B. influenzÆ was found both in the lungs and bronchus or in the bronchus alone in 3 of these 4 cases.

The relation of hemolytic streptococci to the lesion is of interest. In 3 of 4 instances of lobar pneumonia this microorganism had entered the bronchi but was not found in the lungs or in the heart’s blood; and gross and histologic examination showed none of the lesions which are usually caused by it. In 1 instance (Autopsy 508) hemolytic streptococci, absent from the throat when the patient was admitted to the hospital with measles sixteen days before death, appeared in a culture made five days later and was subsequently found three times; it had penetrated into the bronchus but failed to reach the lung. Observations made upon lobar pneumonia following influenza have shown the relative insusceptibility of lobar pneumonia with gray hepatization to secondary infection with hemolytic streptococci (p. 160). Autopsy 508 demonstrates that occurrence of hemolytic streptococci in the sputum of a patient with pneumonia does not furnish conclusive proof of the existence of streptococcus pneumonia.

Bronchopneumonia.—Bronchopneumonia has been found in every instance of pneumonia following measles save 3, namely in Autopsy 486, Autopsy 505 with lobar pneumonia and Autopsy 507 with interstitial suppurative pneumonia. It is not improbable that further histologic study might have demonstrated small patches of peribronchiolar pneumonia, for purulent bronchitis was present in the two autopsies with lobar pneumonia. This small group of cases has reproduced all of the important features of bronchopneumonia following influenza. Hemorrhagic peribronchiolar consolidation characterized by the presence of small gray spots clustered about terminal bronchi upon a homogeneously red background has been found in 5 of 18 instances of pneumonia with measles. Pfeiffer regarded this lesion as characteristic of the pneumonia of influenza. Peribronchiolar patches of consolidation with no surrounding hemorrhage were found in 14 instances, being recognized first by microscopic examination in half of this number. Lobular consolidation occurred in 11 autopsies and peribronchial fibrinous pneumonia was present in a third of the autopsies on patients with pneumonia of measles.

Bronchial, peribronchial and intraalveolar hemorrhage is much more commonly associated with the pneumonias of influenza than with the more familiar types of acute bronchopneumonia. Exuded blood may undergo absorption; and with bronchopneumonia which, persisting unresolved, has assumed the characters of a chronic lesion, it is common to find mononuclear cells often in great abundance filled with brown pigment derived from the hemoglobin of red blood corpuscles.

Autopsy 439 is an example of acute hemorrhagic bronchopneumonia; there are red lobular and confluent lobular patches of consolidation which upon the pleural surface have a blue or purplish color. In the dependent part of the left lung occupying a large part of the lower lobe there is lax, red consolidation marked by gray or yellowish gray spots of peribronchiolar pneumonia and in this lobe bronchi are encircled by zones of hemorrhage. Pneumococcus II atypical was obtained from the lung. In Autopsy 444 the lesion has the same hemorrhagic character although lobular patches are in a stage of grayish red hepatization. Pneumococcus II atypical has been found in the heart’s blood, and with B. influenzÆ in lungs and bronchus. Autopsy 441 is an example of the occurrence of conspicuous nodules of peribronchiolar consolidation in some parts of the lungs with the same lesion in other parts on a background of hemorrhage. B. influenzÆ and S. aureus have been found in both lungs and bronchi.

Steinhaus^[102] states that the pneumonia of measles is never lobular inflammation but occurs in small patches several of which may be found in a single lobule.

Chronic fibroid pneumonia following measles characterized by cellular infiltration and proliferation of the interstitial tissue of the lung has been described by Bartels,^[103] Steinhaus,^[104] Hart,^[105] MacCallum^[104] and others.

The incidence of unresolved bronchopneumonia among instances of bronchopneumonia following measles is higher than that among bronchopneumonias following influenza. There have been 6 instances of chronic or unresolved bronchopneumonia among 18 pneumonias following measles, namely 33.3 per cent. The incidence of unresolved bronchopneumonia among 241 autopsies on pneumonia following influenza has been 21, namely 8.7 per cent. The essential features of this chronic lesion have been as follows: (a) chronic peribronchiolar pneumonia indicated by the presence of firm nodules of peribronchiolar consolidation which have considerable resemblance to miliary tubercles. Induration of the nodule occurs because the walls of alveoli surrounding and adjacent to a respiratory bronchiole (Fig. 31) become thickened and infiltrated with cells and there is organization of exudate within the alveoli. New formation of fibrous tissue (Fig. 32) occurs where the acute inflammatory reaction of peribronchiolar consolidation is most advanced (p. 169 and compare with Figs. 3 and 4), namely, about the respiratory bronchiole, alveolar duct and the proximal parts of the infundibula, disappearing as the distal half of the infundibulum is approached. Distention of the alveoli explaining the distention of the lung and its failure to collapse on section is a noteworthy feature of the lesion. (b) Chronic peribronchial inflammation (Fig. 30) with new formation of fibrous tissue about the smaller and medium-sized bronchi extending into immediately adjacent alveolar walls and often associated with organization of peribronchial fibrinous pneumonia. (c) Chronic lobular inflammation with changes similar to those just cited, distributed throughout entire lobules. (d) Moderate thickening of interlobular septa. Bronchiectasis may be associated with the chronic lesion (Autopsies 443, 481, 484, 492 and 496) but with one exception (Autopsy 443) has been only moderately advanced. Suppurative pneumonia with abscess formation has occurred twice (Autopsies 438 and 492).

With acute bronchopneumonia following measles the average duration of pneumonia, determined by the date upon which physical signs of pneumonia were first recognized and in consequence subject to some error, was seven days; in instances of chronic bronchopneumonia the average duration of pneumonia has been fifteen days.

The bacteriology of acute bronchopneumonia following measles is shown in Table LXXII.

It is noteworthy that pneumococci have been recovered from the heart’s blood or lung in all but 1 (Autopsy 441) of 5 instances of acute bronchopneumonia with no suppuration and is doubtless the cause of this pneumonia. Pneumococcus II atypical has been found in 3 of 4 instances of lobar pneumonia following measles and is present in 3 of these 5 instances of bronchopneumonia.

Where suppuration has been found, hemolytic streptococci have been present in the sputum, in the heart’s blood and either in the lungs (Autopsy 491) or in the bronchi (Autopsy 442) or in both (Autopsy 507). In these instances pneumococci have not been found, though in view of the readiness with which pneumococci disappear from the lungs it is possible that they have been the primary cause of bronchopneumonia.

The bacteriology of 6 instances of unresolved bronchopneumonia following measles is given in Table LXXIII.

Whereas with acute bronchopneumonia death has been accompanied and perhaps caused by bacterial invasion of the blood by pneumococci or streptococci in 5 of 7 instances, with unresolved or chronic bronchopneumonia, bacteriemia has been present only once, namely, in Autopsy 492 in which with suppurative pneumonia hemolytic streptococci have entered the blood. It is probable that pneumococci have likewise had an important part in the causation in these instances of bronchopneumonia which have run a chronic course but in all save 2 cases (Autopsies 438 and 492) have disappeared from the lungs. Pneumococcus II atypical has been found twice.

B. influenzÆ has been found in association with acute bronchopneumonia in the lungs in 1 of 6 examinations and in the bronchi in 5 of 6 examinations. These figures indicate that it is present in small numbers if at all in the consolidated lung tissue but is relatively abundant in the bronchi. With chronic bronchopneumonia B. influenzÆ has been found in every instance, in half of the examinations of lungs and in all of the examinations of bronchi. In 1 instance (Autopsy 481) B. influenzÆ has been found in pure culture in the lung; Pneumococcus II atypical has been found in the bronchus and has perhaps disappeared from the pneumonic lung, since this microorganism is often destroyed in the late stages of pneumonia so that its demonstration at autopsy is no longer possible. In 1 instance B. influenzÆ found in the bronchus has been the only microorganism isolated at autopsy, although the sputum during life contained B. influenzÆ and Pneumococcus IV.

Suppurative Pneumonia.—Suppurative pneumonia with formation of abscesses has occurred in 2 autopsies with pneumonia following measles (Autopsies 438 and 492), both instances of chronic bronchopneumonia. In Autopsy 438 the lower and posterior part of the left lower lobe has been consolidated and has had on section a cloudy, grayish red color; within this area of consolidation and immediately below the pleural surface there have been opaque, yellow spots where the tissue has been softer than elsewhere. Microscopic examination shows that the tissue has here undergone widespread necrosis so that all nuclear stain has disappeared; at the edges of the necrotic tissue polynuclear leucocytes are often present in large numbers, but necrosis is much more conspicuous than suppuration. In the necrotic tissue and at its edges streptococci are present in vast numbers. Hemolytic streptococci have been grown both from the lung and from the bronchus, but these have not been the only microorganisms present, for Pneumococcus II atypical and S. viridans have been obtained from the lungs and B. influenzÆ from lungs and bronchus.

In Autopsy 492 with chronic bronchopneumonia the posterior half of the right lower lobe is laxly consolidated, deep red in color and with the cloudy appearance often associated with streptococcus pneumonia; upon this background are peribronchiolar spots of yellow color, in places well seen below the pleura; in the corresponding part of the left lower lobe similar nodules have been converted into small abscesses by central suppuration. There is empyema on the right side, fibrinopurulent pericarditis, and purulent peritonitis. Hemolytic streptococci had been found in the sputum three times, the first examination being thirteen days before death. This microorganism is found in pure culture in the blood of the heart and with Pneumococci IV, B. coli and B. influenzÆ in the lung. Hemolytic streptococci were found in the right pleural exudate and peritoneum.

The pneumonias following measles give opportunity to consider the relationship of suppurative interstitial pneumonia to unresolved or chronic bronchopneumonia, which is characterized by infiltration and proliferation of the fibrous tissue of the lungs. A number of those who have studied the pneumonia of measles have recognized that this chronic interstitial lesion is a common sequela of measles. MacCallum has designated the lesion “interstitial bronchopneumonia,” and has included under this name its acute stage in which the interstitial character of the lesion is not more evident than with other forms of acute bronchopneumonia. He has regarded S. hemolyticus as the cause of “interstitial bronchopneumonia” following measles. A review of the autopsies which he has described shows that he has included under the same designation typical instances of interstitial suppurative pneumonia associated with suppurative lymphangitis. Instances of unresolved, chronic or “interstitial” bronchopneumonia and of interstitial suppurative pneumonia which we have observed after measles, demonstrate that the two lesions are distinguishable both by their anatomic characters and by their etiology.

Three instances of suppurative interstitial pneumonia occurred among the pneumonias following measles (Autopsies 442, 491 and 507). The lesion is characterized by suppuration of the interlobular septa and particularly noteworthy is the occurrence of suppurative lymphangitis, lymphatics being immensely dilated and distended with purulent fluid so that their irregularly dilated, beaded appearance is recognizable upon the section of the lung. In the group of pneumonias following measles this lesion has not been associated with unresolved or chronic bronchopneumonia; no nodular tubercle-like foci of bronchopneumonia have been found at autopsy, and there has been no thickening of the interstitial tissue. The lesion has accompanied confluent lobular pneumonia in 2 instances (Autopsies 442 and 491). In the third instance (Autopsy 507) there was in the neighborhood of the suppurative lesions diffuse consolidation which had the cloudy, gray red color of streptococcus pneumonia, but this consolidation was not lobular in distribution.

The etiology of interstitial suppurative pneumonia established by study of instances following influenza is confirmed by Table LXXII (p. 345) showing the bacteriology of instances of acute bronchopneumonia following measles. Pneumococci are almost invariably found in uncomplicated instances of bronchopneumonia and hemolytic streptococci have been absent, whereas in 3 instances of suppurative interstitial pneumonia hemolytic streptococci have been found in the sputum during life, in pure culture in the blood of the heart and in the lungs and bronchus (missed in the bronchus in one instance, Autopsy 507). In the 3 instances of the disease B. influenzÆ has been found in the bronchi.

Table LXXIII shows that suppuration has accompanied unresolved bronchopneumonia (“interstitial bronchopneumonia”) in 2 instances (Autopsies 438 and 492), but in these instances the interlobular tissue of the lung has not been the site of suppuration and there has been no suppurative lymphangitis. Localized abscesses have been formed; hemolytic streptococci, as with abscesses following influenza, have been found.

Empyema has occurred only 5 times in association with pneumonia following measles and in these 5 instances has been associated with suppurative pneumonia caused by hemolytic streptococci. In Autopsy 492 there was fibrinopurulent pleurisy on both sides. Aspiration had been performed 3 times and at autopsy the right pleural cavity contained 150 c.c. of purulent fluid. In small pockets, corresponding to shallow oval depressions upon the anterior surface of the lung, fluid was walled off from the general cavity. The pericardial cavity contained 25 c.c. of turbid yellow fluid containing yellow flakes of fibrin and the peritoneal cavity contained thick purulent fluid. Hemolytic streptococci present in the heart’s blood and lung were recovered from the right pleural cavity and from the peritoneum. Among 3 instances of empyema accompanying interstitial suppurative pneumonia, in 1 (Autopsy 491) there were walled off pockets of fluid similar to those just described. Aspiration of the right pleural cavity had been performed 3 times; at autopsy 100 c.c. of fibrinopurulent fluid was found on the right side and 450 c.c. on the left. There was general purulent peritonitis and the peritoneal cavity contained 350 c.c. of thick yellow pus. Hemolytic streptococci were obtained from the heart’s blood, right lung, right pleural cavity and peritoneum.

Among 4 instances of lobar pneumonia following measles there was serofibrinous pleurisy 3 times; in 1 instance there is no record of pleural change. In 1 instance of lobar pneumonia (Autopsy 505) the right pleural cavity contained 800 c.c. of serofibrinous exudate and the pericardial cavity contained 510 c.c. of opaque, yellow seropurulent fluid; Pneumococcus II atypical in pure culture was obtained from the blood, lung and pleural and pericardial exudates. Among 9 instances of bronchopneumonia following measles there was fibrinous pleurisy 3 times, serofibrinous 3 times, and no recorded lesion of the pleura 3 times. Empyema, like suppurative pneumonia following measles, is in most instances, but not constantly, caused by invasion of hemolytic streptococci.

The foregoing study has shown that pneumonia which has followed measles has reproduced all of the lesions usually found after influenza. There is no pulmonary lesion peculiar to measles. Lobar pneumonia follows the disease in some instances, but bronchopneumonia with purulent bronchitis is more common. The same tendency to hemorrhagic inflammation found with the pneumonia of influenza is seen after measles. Unresolved pneumonia with chronic inflammatory changes in the interstitial tissue of the lung has all of the characters of the similar lesion following influenza but has been found in a larger proportion of the pneumonias of measles.

B. influenzÆ has been found in the bronchi in 14 of 16 examinations, namely in 87.5 per cent of fatal instances of pneumonia. In 1 instance in which B. influenzÆ has not been found at autopsy, it has been isolated from the sputum during life. It is not improbable that B. influenzÆ has been constantly present in the inflamed bronchi both after influenza and measles. It is noteworthy that the outbreak of pneumonia following measles has been in part coincident with, in part slightly subsequent to, an epidemic of influenza which has exposed every individual in the camp to infection with this disease.

B. influenzÆ has been found in the lung with the pneumonia of measles in 7 of 17 examinations, namely, in 41.2 per cent of instances. The microorganism with measles, as with influenza, is found in the inflamed lung only half as frequently as in the bronchi. It appears to be peculiarly adapted for multiplication within the bronchial tubes, and its isolation from the inflamed lung in less than half of the cases of pneumonia is perhaps referable to its presence in the small bronchi and bronchioles. The presence of B. influenzÆ in the lungs in pure culture in 3 instances at first sight suggests that the microorganism produces pneumonia, but a more intimate survey of these cases gives little support to this view. In Autopsy 450 B. influenzÆ has been found in pure culture in the lung, but Pneumococcus IV has been isolated from the blood of the heart and has been with little doubt the cause of typical lobar pneumonia present in this instance. In Autopsy 486 the condition is almost identical, for in the presence of lobar pneumonia B. influenzÆ has been found in the lung in pure culture, but Pneumococcus II atypical has been isolated from the pleural cavity and from the bronchus; in both autopsies the pneumococci which have caused lobar pneumonia have disappeared from that part of the consolidated lung from which a culture has been made; and here doubtless its invasion has been effectively resisted although it is still present in other organs. In Autopsy 481 in which B. influenzÆ has been isolated from the lung in pure culture, the part of pneumococci in the production of the fatal disease is less evident; in this instance, Pneumococcus II atypical, S. hemolyticus and B. influenzÆ have been isolated from the bronchus.

The presence of microorganisms which have a well-established etiologic relation to pneumonia explains the occurrence of pneumonia and makes unnecessary the assumption that B. influenzÆ, which is present in the lungs in less than half of the instances examined, is essential to the production of the pneumonic consolidation. In view of the well-recognized etiology of lobar pneumonia we may conclude that this lesion is referable to the pneumococci (Pneumococcus II atypical in 3 instances and Pneumococcus IV in 1 instance) isolated from the autopsies in which this lesion occurred. Pneumococcus (Pneumococcus II atypical in 3 instances and Pneumococcus I in 1 instance) has been isolated from the lungs or heart’s blood in 4 of 5 instances of acute bronchopneumonia unaccompanied by suppuration. With unresolved bronchopneumonia with no suppuration, pneumococci have been in no instance found in the lungs or blood though their presence in the washed sputum during life or in the bronchus at autopsy suggests the possibility that they may have disappeared from the lungs.

In all instances in which suppuration has occurred hemolytic streptococci have been found in the lungs or blood, or in both. The occurrence of pneumococci in the lungs in 2 of 5 instances of suppurative pneumonia indicates that infection with S. hemolyticus is in some instances at least superimposed upon acute bronchopneumonia caused by pneumococci. Bronchopneumonia in 3 instances has the character of that caused by pneumococci. It is probable that the sequence of infection frequently observed after influenza, namely, bronchial infection by B. influenzÆ, followed by pneumonia caused by pneumococci, followed in turn by infection by hemolytic streptococci with necrosis or suppuration, is not uncommon after measles.

Pneumonia Associated with Acute Infectious Diseases Other than Influenza and Measles.—A small group of autopsies have been excluded from the list of those which accompanied the epidemic of influenza, because pneumonia has been associated with an acute infectious disease to which it is perhaps secondary. These few instances of pneumonia, like those following measles reproduce characters of the pneumonia following influenza and may be in part referable to influenza which has attacked an individual suffering with typhoid fever, mumps or scarlet fever.

In 2 instances pneumonia followed typhoid fever and appeared on September 23 and 26 shortly after the epidemic of influenza had become evident. In the following autopsy there was acute lobar pneumonia which appeared ten days after onset of typhoid fever.

Autopsy 245.—O. H., white, aged twenty-one, a farmer, resident of Oklahoma, had been in military service twenty-one days. Onset of illness was on September 13 with chill, headache, cough and nausea. The patient was admitted two days later with the diagnosis of acute bronchitis. On September 20 the abdomen was tense, the spleen was enlarged and rose spots were present. Signs of lobar pneumonia were found September 23. Death occurred September 25, twelve days after onset of typhoid fever and two days after recognition of pneumonia.

Anatomic Diagnosis.—Typhoid fever with necrotic ulcers in lower ileum and in colon; hyperplasia of ileocecal lymphatic nodes; acute splenic tumor; parenchymatous degeneration of liver and kidneys; acute lobar pneumonia with gray hepatization in left lower lobe and red hepatization and edema in left upper lobe and in right lung; serofibrinous pleurisy on left side.

The left pleural cavity contains 75 c.c. of yellowish gray turbid fluid. Over the left lower lobe there is a layer of fibrin. The upper half of the lobe is firmly consolidated, pinkish gray and coarsely granular; the bronchi contain plugs of fibrin. The lower and posterior part of the lower lobe is consolidated deep red and edematous. The left upper lobe is edematous and a layer in the lowermost part in contact with the lower lobe is deep red and consolidated. The left lung weighs 1,490 grms. The lower half of the right upper lobe and the posterior border of the lower is consolidated deep red and edematous; the lung weighs 970 grms.

Bacteriologic examination shows that the blood of the heart contains Pneumococcus II atypical.

The foregoing autopsy is of interest because typical lobar pneumonia appears to have spread from the left lower lobe, where consolidation is firm and gray, to the adjacent part of the upper lobe where consolidation is red and edematous.

The second instance of pneumonia following typhoid fever is an instance of suppurative pneumonia caused by S. aureus.

Autopsy 329.—J. B., white, aged twenty-two, laborer, resident of Oklahoma, had been in military service two days before onset of symptoms of typhoid fever. He was admitted to the hospital on August 27 and B. typhosus was found in cultures from the blood on September 2 and 3. Acute bronchitis appeared on September 26 when the epidemic of influenza had almost reached its height. A diagnosis of bronchopneumonia was made on the day preceding death, which occurred forty-one days after onset of typhoid fever and eleven days after onset of bronchitis.

Anatomic Diagnosis.—Typhoid ulcers of ileum; acute splenic tumor; acute bronchopneumonia with red hemorrhagic peribronchiolar and lobular consolidation in right lung; multiple abscesses forming a circumscribed group in left upper lobe; purulent bronchitis.

The pleural cavities contain no excess of fluid. The lungs are voluminous and there is interstitial emphysema. Below the pleura are bluish red spots of lobular consolidation; in the right upper lobe is a large patch of red consolidation marked by yellowish gray spots in clusters. In the external and upper part of the left upper lobe is a patch of gray consolidation within which, beneath the pleura, there are small abscesses grouped to form a cluster 1.5 cm, across.

Bacteriologic examination demonstrates no microorganisms in the blood of the heart; of two cultures from the left lung one contains S. aureus in pure culture, the other S. aureus and a few colonies of Pneumococcus IV. Cultures from the left main bronchus and from the mucopurulent exudate in a small bronchus both contain B. influenzÆ, S. aureus and Pneumococcus IV.

In the foregoing case bronchitis has appeared thirty days after onset of typhoid fever on September 26, immediately preceding the height of the epidemic of influenza. In association with hemorrhagic bronchopneumonia there is suppurative pneumonia with small abscesses forming a circumscribed group below the pleura; there is no empyema. The lesion has the characters of the staphylococcus abscesses following influenza, and S. aureus is found in association with the lesion; B. influenzÆ is identified in two cultures from the bronchi.

In 2 instances pneumonia was associated with parotitis which was diagnosed mumps.

Autopsy 403.—C. T., colored, aged twenty-five, a laborer, resident of Arkansas, had been in military service one month. Illness began September 27 with swelling of face behind jaw and difficult mastication; the patient was admitted to the hospital on the same day with the diagnosis of mumps. Pneumonic consolidation was recognized on October 8. Death occurred October 13, sixteen days after onset of illness and six days after recognition of pneumonia.

Anatomic Diagnosis.—Acute lobar pneumonia with red and beginning gray hepatization of lower and parts of upper and middle right lobes; acute bronchopneumonia with lobular consolidation in left lung; purulent bronchitis; bronchiectasis in left lung.

The lower lobe of the right lung with the exception of the anterior and basal edge is firmly consolidated; the posterior part of the middle lobe and a small corner at the posterior and lower part of the upper lobe is similarly consolidated. The consolidated tissue is gray and coarsely granular on section. The remainder of the lung is dry and voluminous, and the bronchi contain purulent fluid. The left lung contains red and gray patches of consolidation, from 0.2 to 3 cm. across. Bronchi contain purulent fluid and in the lowermost parts of both upper and lower lobes are moderately dilated.

Bacteriologic examination shows that the blood of the heart contains Pneumococcus III.

It is noteworthy that there was in this case, as in many instances of influenza, both lobar and bronchopneumonia. Purulent bronchitis was present and there was bronchiectasis throughout one lung.

In the following case the diagnosis of mumps may be questioned since the lesion of the parotid has characters of terminal suppurative parotitis.

Autopsy 417.—H.W.D., white, aged twenty-four, a farmer, resident of Oklahoma, had been in military service one month. He said that he had had pneumonia four times. He was admitted to the hospital delirious and the diagnosis of lobar pneumonia was made. Parotitis regarded as mumps appeared five days before death and suppuration occurred on the right side of the face. Death of the patient occurred thirteen days after admission to the hospital.

Anatomic Diagnosis.—Acute bronchopneumonia with lobular consolidation in both lungs; suppurative pneumonia with necrosis and beginning abscess formation in left lung; purulent pleurisy in left side; purulent bronchitis; bronchiectasis; acute parotitis.

The left pleural cavity contains 100 c.c. of purulent fluid of creamy consistence. The left lung is voluminous and bound to the chest wall in places. There are numerous patches of lobular consolidation. At the apex of the lung there is a large area of consolidation, 7 cm. across, where the tissue is cloudy gray and soft in consistence. In the upper lobe is a well-defined patch of grayish yellow color, 6 by 2 cm., with opaque yellow edges; purulent fluid escapes from the cut surface. Bronchi throughout the lung are widely dilated and contain purulent fluid. The right lung is voluminous and contains lobular patches of consolidation; bronchi of this lung are widely dilated.

Bacteriologic examination shows the presence of hemolytic streptococci in the blood of the heart; hemolytic streptococci and B. influenzÆ in the lung, and hemolytic streptococci, B. influenzÆ and S. aureus in a main bronchus.

In association with bronchopneumonia there have been necrosis and beginning abscess formation with empyema, the suppurative lesions being caused by hemolytic streptococci which had finally entered the blood stream. There was purulent bronchitis, and the lungs had the voluminous character often associated with this lesion; there was beginning bronchiectasis. B. influenzÆ was obtained both from the lung and from the bronchus.

In 2 instances (Autopsies 323 and 335) the diagnosis of scarlet fever was made in patients suffering with pneumonia following influenza. These lesions have been included in the list of influenzal pneumonias. In the following instance the patient was admitted with scarlet fever, later developed acute follicular tonsillitis, and finally suppurative pneumonia caused by hemolytic streptococcus.

Autopsy 311.—E. J., white, aged twenty-two, a tinsmith and automobile repairer, resident of Arkansas, had been in military service three months. Onset of illness was on September 18 with headache and sore throat. The patient was admitted September 24 with the diagnosis of scarlet fever; two days later there was acute follicular tonsillitis. Pneumonic consolidation on the right side was recognized October 2, three days before death.

Anatomic Diagnosis.—Acute suppurative pneumonia with three small abscesses below pleura of right lower lobe; acute fibrinopurulent pleurisy on both sides; serous pericarditis.

The right pleural cavity contains 1500 c.c. of turbid, dirty yellow fluid containing masses of fibrin; the left cavity has 500 c.c. of similar contents. The pericardium contains 30 c.c. of turbid fluid containing a small quantity of fibrin; there are ecchymoses below the epicardium. The right lung is collapsed and in the lower lobe contains three small subpleural abscesses, the largest of which is 1.5 cm. across.

Bacteriologic examination shows the presence of hemolytic streptococci in pure culture in the blood of the heart and in the right lung. From the right main bronchus are obtained hemolytic streptococci, B. influenzÆ, Pneumococcus IV and a few staphylococci.

In this instance there has been infection with streptococcus which is a common sequela of scarlet fever. In the absence of evidence of bronchopneumonia there has been abscess formation below the pleura with empyema and pericarditis. B. influenzÆ has been found in the bronchus.

The pneumonias found in association with measles reproduce the characters of the pneumonias described in association with influenza. Particularly noteworthy is the occurrence of lobar pneumonia, hemorrhagic peribronchiolar pneumonia, interstitial suppurative pneumonia, severe bronchitis with bronchiectasis and unresolved bronchopneumonia. In the presence of an epidemic of influenza attacking more than one fourth of the population of a camp, those suffering with diseases, such as measles, typhoid fever, mumps, etc., are unlikely to escape entirely, and it is probable that the tendency to the occurrence of pneumonia present in association with these diseases will be increased. The close resemblance between the pneumonias which we have found with the diseases mentioned, on the one hand, and the pneumonias of influenza on the other, both being characterized by the occurrence of hemorrhagic, suppurative and chronic pulmonary lesions, indicates that influenza has had a part in the production of the pneumonia found with measles and some other infectious diseases during the progress of the epidemic of influenza.