The relation of these pneumonias following measles, to the influenza epidemic has been discussed. The time relations between the onsets of measles and that of the subsequent pneumonia vary widely. There appears to be nothing constant in the length of time between the onset of measles and that of the pneumonia. In 30 of the cases this period is less than ten days; in the remaining 26 cases, it ranges from ten to thirty-two days (Chart 4).

In the ward treatment of these cases of pneumonia, they were divided into three groups according to their clinical characters and according to the results of throat and sputum cultures.

The streptococcus-free cases were treated in a separate ward. Cases were admitted to this ward directly from the “clean” measles wards, but only after a throat culture taken prior to their transfer had been negative for the hemolytic streptococcus.

The other two groups were treated together in another ward, but in strictly separate compartments of it. This precaution was carried out on the assumption that patients with an acute streptococcus pneumonia were real sources of danger in the ward because of a heightened virulence of the organism causing the grave symptoms. The pneumonias subsequently developing hemolytic streptococci in their throats, without their presence modifying the course of the pneumonia, came to be regarded as being in the same class with uncomplicated cases of measles carrying hemolytic streptococci, in so far as their being potential sources of danger in a ward is concerned.

(a) Streptococcus Pneumonias.—Nine cases of streptococcus pneumonia developed. Of the 867 cases of measles studied, 242 showed throat cultures positive for the hemolytic streptococci at some period of their stay in the hospital. It appears then that 3.7 per cent of the patients carrying hemolytic streptococci in their throats developed streptococcus pneumonia. Thirty-seven cases had positive throat cultures when first observed on admission to the measles wards. It is significant to note that not a single case of pneumonia of any kind developed among these cases.

MEASLES PNEUMONIA; STREPTOCOCCUS GROUP

Case 98, O. McN. Onset of measles, Sep. 19; admitted to hospital Sep. 21; onset of bronchopneumonia, Oct. 21; of empyema, Oct. 23. Recovered from pneumonia; convalescent in empyema ward.

Bacteriology.—1. Throat culture for: (a) S. hem.: Sep. 21, −; 28, −; Oct. 9, −; 20, −; 23, +; Nov. 2, −; 9, −; 15, −; (b) B. influenzæ: Sep. 21, +; 28, −; Oct. 9, +. 2. Pleural fluid (culture) S. hem. Oct. 23, +.

Case 141, J. G. G. Autopsy No. 438. Onset of measles, Sep. 28; admitted to hospital, Oct. 1; onset of bronchopneumonia, Oct. 6; of otitis media (bilateral), Oct. 12; died, Oct. 18.

Bacteriology.—1. Throat culture for: (a) S. hem., Oct. 2, −; 6, −; 8, −; (b) B. influenzæ, Oct. 2, −; 6, +; 8, +. 2. Autopsy cultures: Heart blood, negative; left lung, Pneumococcus II atypical, B. influenzæ and S. viridans; right lung, S. hem. and B. influenzæ; right bronchus, S. hem. and B. influenzæ.

Case 147, S. W. Autopsy No. 442. Onset of measles, Oct. 1; admitted to hospital, Oct. 2; onset of bronchopneumonia, Oct. 17, with chill and rapid development; died, Oct. 18.

Bacteriology.—1. Throat culture for: (a) S. hem., Oct 2, −; 9 −; 15, −; 18, +; (b) B. influenzæ, Oct. 2, −; 9, −; 15, −; 18, −. 2. Autopsy cultures: Heart blood, S. hem.; right main bronchus, S. hem. and B. influenzæ.

Case 281, T. M. Onset of measles, Oct. 6; admitted to hospital Oct. 9; onset of bronchopneumonia, Oct. 21; of empyema, Oct. 23; recovered from pneumonia; convalescent in empyema ward.

Bacteriology.—1. Throat culture for: (a) S. hem., Oct. 10, −; 20, −; 24, +; Nov. 2, +; 9, +; 15, +; (b) B. influenzæ, Oct. 10, −; 20, +. 2. Culture from pleural fluid, Oct. 23, S. hem.

Case 285, J. H. Onset of measles, Oct. 4; admitted to hospital, Oct 9; onset of lobar pneumonia, Oct. 29; of empyema, Nov. 9; convalescent in empyema ward.

Bacteriology.—1. Throat cultures for: (a) S. hem., Oct. 11, −; 20, −; 24, +; 29, −; Nov. 2, −; 9, −; (b) B. influenzæ, Oct. 11, −. 2. Cultures from pleural fluid, Nov. 9 and 13, S. hem.

Case 714, W. H. Onset of measles, Oct. 26; admitted to hospital, Oct. 28; otitis media, Nov. 8; onset of bronchopneumonia, Nov. 9; of empyema, Nov. 17; convalescent in pneumonia ward.

Bacteriology.—1. Throat cultures for: S. hem., Oct. 28, −; Nov. 4, −; 12, +; 23, +; 30, +; Dec. 7, +; 12, −. 2. Sputum: Nov. 10, Pneumococcus II atypical, S. hem. and B. influenzæ.

Case 730, W. S. Autopsy No. 491. Onset of measles, Oct. 26; admitted to hospital, Oct. 29; onset of bronchopneumonia, Nov. 10; of empyema, Nov. 11; of cervical adenitis, Nov. 5; died, Nov. 15.

Bacteriology.—1. Throat culture for: S. hem., Oct. 30, −; Nov. 4, +. 2. Sputum: Nov. 10, S. hem. 3. Pleural fluid: Nov. 11, S. hem. Autopsy bacteriology: Heart blood, S. hem.; right main bronchus, B. influenzæ, B. coli; right lung, S. hem. and B. influenzæ; right pleura, S. hem.; peritoneum, S. hem.

Case 751, P. B. Autopsy No. 492. Entered hospital, Oct. 19; onset of measles, Oct. 30; of bronchopneumonia, Nov. 5; of right empyema, Nov. 12; died, Nov. 16.

Bacteriology.—1. Throat cultures for: S. hem., Nov. 1, −; 4, +; 15, +. 2. Sputum: Nov. 13, B. influenzæ and S. hem. 3. Autopsy cultures: Heart blood, S. hem.; right lung, S. hem., Pneumococcus IV, B. influenzæ, B. coli; pericardium, negative; right pleura, S. hem.; peritoneum, S. hem.

Case 880, B. McN. Autopsy No. 507. Onset of measles, Nov. 30; entered hospital, Dec. 3; onset of bronchopneumonia, Dec. 11; of empyema, Dec. 14; died, Dec. 14.

Bacteriology.—1. Throat cultures for: S. hem., Dec. 3, −; 5, −; 12, +. 2. Cultures from pleural fluid, Dec. 14, S. hem. 3. Autopsy cultures: Heart blood, S. hem.; right main bronchus, S. hem., B. influenzæ, staphylococcus (a few); left lung, S. hem.; left pleura, S. hem.

The average period in the hospital before the development of the streptococcus pneumonia is about two weeks. Cases 98 and 285 were in the hospital thirty and twenty days respectively before the onset of pneumonia. There is a record of from one to four negative throat cultures on each case before streptococcus was found in the throat. This enables us to fix the onset of the pneumonia with reference to the appearance of the streptococcus in the throat.

Case 141 stands alone as representing a class in which S. hemolyticus was implanted upon a pneumococcus pneumonia during its course. In this instance two throat cultures on alternate days after the onset of the pneumonia were negative for hemolytic streptococci. Unfortunately the last record of a throat culture is for one taken ten days before the fatal termination of the case, and it can only be stated that the S. hemolyticus infection was implanted within the last ten days of the course of the pneumonia, perhaps on or about October 12 when bilateral otitis media developed.

In Cases 285 and 730 hemolytic streptococci were found in the throats five and six days respectively before the onset of pneumonia. They represent the 2 cases of pneumonia which developed in patients isolated in the streptococcus “carrier” ward. Case 285 is of particular interest for several reasons. It is the only case of lobar pneumonia in the group and happens also to be the only case from which B. influenzæ was not obtained. S. hemolyticus was found only once on throat culture, i.e., five days before the onset of the pneumonia. Three throat cultures after the onset of the pneumonia were negative. The case ran the course of a lobar pneumonia. Eleven days after the onset (November 9) a small amount of pleural fluid was diagnosed. Aspirated fluid on this date and again four days later showed many streptococci in smears and pure cultures of S. hemolyticus.

The remaining 6 cases belong to a group in which hemolytic streptococci were first identified in the throats after the cases had been reported to the laboratory as pneumonia suspects to be examined by culture before transfer from the measles ward. In all these cases the culture taken at this time was positive while all cultures taken before were negative. In some cases, e. g., Cases 98, 147, and 281, throat cultures taken only one or two days before the onset of the pneumonia were negative. In these cases the onset of the pneumonia and the appearance of the streptococcus in the throats appear to be simultaneous.

It should be noted that the period between the appearance of the hemolytic streptococci in the throat and the development of the pneumonia is very short in all cases. In this small group of cases S. hemolyticus infection which has complicated pneumonia has been acquired at or near the time of onset of the pneumonia.

(b) Pneumonia with Hemolytic Streptococci in the Throat without Symptoms Referable to the Streptococcus.—Thirteen cases of pneumonia associated with measles developed into S. hemolyticus “carriers” without having the course of the disease affected by the presence of the organism in the throat. Cases 705, 872, and 188 are of interest in that hemolytic streptococci were identified in the throats from one to six days prior to the onset of the pneumonia. In spite of their presence, the symptoms, course and outcome of the pneumonia were apparently unaffected. One of these cases (Case 872) died. Autopsy showed lobar pneumonia with no signs of invasion of the lung by hemolytic streptococci. Cultures at autopsy showed that pneumonia was due to a pneumococcus, Type II atypical. A few hemolytic streptococci were found in culture from the right main bronchus.

Of the remaining 10 cases 1 developed S. hemolyticus in a throat culture at the end of the first week of the pneumonia; 3 during the second week; 1 during the third week, and 5 further along in the convalescent period. In 8 cases hemolytic streptococci appeared in the throat, at a time when invasion of the lower respiratory tract by the streptococcus might be expected, and yet none of them developed evidence of streptococcus pneumonia. The 9 cases with hemolytic streptococci appearing late in convalescence are not of particular interest, since the dangers of lower respiratory invasion are much reduced after the acute stage of the pneumonia has passed. Three of these cases (Cases 678, 725 and 398) did however develop ear complications directly referable to the streptococcus invasion of the throat. Two of them terminated in mastoiditis with operation. These cases emphasize the greater tendency of S. hemolyticus to invade the middle ear rather than the lung.

In 3 fatal cases of pneumococcus pneumonia in which during life no hemolytic streptococci were found by throat culture, a few hemolytic streptococci were found at autopsy in culture from the main bronchi, along with predominating growths of pneumococci and B. influenzæ. In 2 instances there was frank lobar pneumonia and in the third bronchopneumonia; there was no evidence to show that hemolytic streptococci had any relation to the pneumonia which was found.

MEASLES PNEUMONIAS; GROUP CARRYING HEMOLYTIC STREPTOCOCCI

Case 705. Onset of measles, Oct. 25; admitted to hospital, Oct. 27; onset of bronchopneumonia, Nov. 10; acute pleurisy, Nov. 16; convalescent in pneumonia ward.

Bacteriology.—1. Throat cultures for: S. hem., Oct. 27, −; Nov. 4, −; 11, +; 15, +; 23, −; 30, −; Dec. 7, −; 12, −. 2. Sputum: Nov. 10, Pneumococcus II atypical, S. hem. and B. influenzæ.

Case 872. Autopsy No. 508. Onset of measles, Nov. 29; admitted to hospital, Nov. 30; onset of lobar pneumonia, Dec. 10; died, Dec. 14.

Bacteriology.—1. Throat cultures for: S. hem., Nov. 30, −; Dec. 5, +; 10, +; 12, +; 14, +. 2. Autopsy culture: Heart blood, Pneumococcus II atypical; right main bronchus, Pneumococcus II atypical, B. influenzæ, S. hem. (a few); left lung, Pneumococcus II atypical; left pleura, Pneumococcus II atypical.

Case 188. Onset of measles, Oct. 3; admitted to hospital, Oct. 4; onset of bronchopneumonia, Oct. 14; recovered and discharged from hospital, Nov. 24.

Bacteriology.—1. Throat cultures for: (a) S. hem., Oct. 5, −; 8, +; 12, +; 19, +; 20, +; 27, −; Nov. 2, −; 9, +; 15, −; (b) B. influenzæ, Oct. 5, −; 8, −; 12, +; 19, +.

Case 678. Onset of measles, Oct. 23; admitted to hospital, Oct. 25; onset of bronchopneumonia, Nov. 2; of otitis media, Nov. 9; of mastoiditis, Nov. 13; mastoid operation, Nov. 20; still under treatment.

Bacteriology.—1. Throat cultures for: S. hem., Oct. 25, −; Nov. 4, −; 5, −; 12, +. 2. Sputum: Nov. 3, Pneumococcus Type IV, and B. influenzæ. 3. Culture from mastoid bone at operation, Nov. 20, S. hem.

Case 389. Admitted to hospital, Oct. 2, with diagnosis of influenza; onset of bronchopneumonia, Oct. 7; onset of measles, Oct. 13; phlebitis (right leg), Oct. 22; otitis media, Oct. 31; recovered.

Bacteriology.—1. Throat cultures for: (a) S. hem., Oct. 16 −; 20, −; 27, +; Nov. 2, +; 9, +; 15, −; 23, −; 30, −; Dec. 7, −; 12, −; (b) B. influenzæ, Oct. 16, −.

Case 725. Onset of measles, Oct. 18; one week in measles barracks; admitted to hospital, Oct. 27; onset of lobar pneumonia, Oct. 23; otitis media, Nov. 7; mastoid operation, Nov. 20; still under treatment.

Bacteriology.—1. Throat cultures for: (a) S. hem., Oct. 29, −; Nov. 1, −; 5, −; 12, +; (b) B. influenzæ, Oct. 29, +. 2. Sputum: Nov. 2, Pneumococcus II atypical. B. influenzæ. 3. Culture from mastoid at operation, Nov. 20, S. hem.

(c) Pneumococcus Pneumonias not Carrying Hemolytic Streptococci.—Thirty-four cases of pneumonia following measles went through their entire course in the hospital with no throat culture positive for hemolytic streptococci. In some of these cases there are records of twelve negative throat cultures. Eleven fatal cases occurred in this group. Autopsy findings and bacteriology showed in each instance that S. hemolyticus was not the cause of the pneumonia.

Measles During the Course of Pneumonia.—Eleven cases of pneumonia which developed measles during the course of the pneumonia came under observation. Hemolytic streptococci appeared in the throats of 3 of these patients during convalescence, but there was no evidence that it invaded the lung. In one fatal case autopsy showed that there was no streptococcus pneumonia; pneumonia followed influenza and the onset of measles occurred three days after the onset of bronchopneumonia.

Bacteriology of Pneumonia Following Measles.—When observations made during life are combined with the results of postmortem cultures, the bacteriology of 35 of the 56 cases is available and is as follows: Pneumococcus Type II atypical in 36 per cent, Type IV in 22.9 per cent, Type I in 2.8 per cent, Type III in 2.8 per cent, hemolytic streptococci in 22.4 per cent, and B. influenzæ in 88.6 per cent of these cases.

Otitis Media and Mastoiditis Complicating Measles.—The occurrence of otitis media and mastoiditis complicating measles in patients harboring hemolytic streptococci in their throats has already been presented (Table LXIV). The bacteriology of these complications was not studied by this commission. The records of the base hospital laboratory at Camp Pike contain reports of twenty-nine cultures made at operation from pus in the middle ear and the mastoid bone. Hemolytic streptococci were found in 22 of these cases. Throat cultures were in accord with these positive findings in all except a few instances. The throat culture serves as a fairly reliable index of the bacterial nature of these complications. By combining our records of throat cultures with the results of the cultures from the lesions, hemolytic streptococci were obtained from 37 of the 48 cases of otitis media. In 23 cases of mastoiditis following the otitis media, hemolytic streptococci were demonstrated in all except 2. It is evident that the great majority of these complications were due to hemolytic streptococci.

The relation between the appearance of hemolytic streptococci in the throat and the onset of the otitis is recorded in all except 4 of the 31 instances of otitis media occurring in patients with throat cultures positive for hemolytic streptococci. These four patients had positive throat cultures when first observed and represent the only patients who carried hemolytic streptococci when admitted to measles wards and developed complications.

The first of these patients had been under treatment in an otologic ward during a month before measles developed. Measles caused a recurrence of disease of the ear with double mastoiditis requiring bilateral operation. Two other patients had been in the hospital ten and eleven days respectively before they were admitted to the measles ward; on admission to the ward otitis media was present in one patient and in the other it developed six days later. The fourth patient was admitted to the measles wards directly from the camp, and culture from the throat on the day of admission showed the presence of S. hemolyticus. Two weeks later at the time of onset of otitis media, culture from the throat contained no hemolytic streptococci. Repeated cultures during the next three weeks were negative. No complications of otitis media developed and no direct cultures from the ear are recorded.

In this series of cases (Chart 5) the appearance of S. hemolyticus in the throat and the onset of otitis media are very closely associated in those patients in whom further extensions of the streptococcus infection occurred. In instances in which appearance of streptococci and of otitis media are separated by an interval of more than seven days, no further extension occurred. In 8 cases in which this interval is seven days or less there has been no further extension of the infection.

The Dissemination of Hemolytic Streptococci in Wards

Beginning October 24 cultures for the identification of carriers of hemolytic streptococci were made from all patients in a ward and repeated at intervals of one week. Prior to this time individual patients had been examined at intervals of one week, so that an entire ward was never studied on any particular day. This system did not identify and remove all “carriers” in a ward at a given time and was abandoned because it failed to show the conditions present. Investigation of wards as units proved much more satisfactory.

The studies made in four of the double wards used for the care of patients with measles are presented in Table LXV. During the time of this study hemolytic streptococci were more prevalent than at an earlier period.

Cultures from the throats of all patients entering these wards were negative for S. hemolyticus on admission. The table showing the incidence of “carriers” of hemolytic streptococci each week in these wards demonstrates:

1. The separation of “carriers” and “noncarriers” by throat culture made on admission does not prevent the increase of streptococcus “carriers” in wards.

2. Removal of all “carriers” found by cultures on admission and at weekly intervals is inadequate.

When the streptococcus complications are traced back to the wards in which the streptococcus infection of the throat was acquired, it is found that with the exception of Case 141 (already cited) all the streptococcus pneumonias arose from two double wards. Wards 41 and 42 furnished 4 cases at times when streptococcus was rampant in them and 3 of these cases arose within a period of a few days. Wards 59 and 60 furnished 4 cases, very closely associated. In 3 cases the streptococcus infection was acquired in a section of Ward 59 containing 16 beds. These patients were in beds, of which the positions are represented by numbers 2, 5, and 7, along one side of the ward. The fourth instance of pneumonia appeared at the same time in Ward 60, which was attended by the same ward personnel, but no other connection can be established between this case and the other three.

The otitis media appeared in patients scattered throughout those wards for measles in which the weekly incidence of “carriers” was rising rapidly. This relation is illustrated by Wards 58, 50, and 41. The same observation applies to streptococcus pneumonia arising in Wards 41 and 42. In Ward 41 the weekly percentage of carriers are October 28, 8.9, November 4, 26.5 and November 11, 66.6. On November 9 and 10 the first 2 cases of streptococcus pneumonia arising from this ward developed. At the same time, November 10, a third case appeared in another part of this same ward unit (Ward 42) where the spread of hemolytic streptococci had been very active. These observations suggest that hemolytic streptococci may build up its virulence as the result of rapid dissemination to such a degree that it is capable of causing grave complications.

The relation of complications to “carriers” in Wards 59 and 60 is different from that in the wards just cited. Wards 59 and 60 were opened on October 9 and before October 17; when the first case of fulminating streptococcus pneumonia occurred, only three “carriers” had been found in them. From October 17 to 24 when the record in Table LXV begins eight “carriers” were removed. The appearance of a case of severe streptococcus pneumonia in an unusually clean ward was followed by the rapid development of “carriers,” and the appearance within twelve days of 3 other cases of streptococcus pneumonia, 2 of which were in beds close to the first case. This sequence suggests focal dissemination of a streptococcus from a case in which it had suddenly assumed high virulence.

An outbreak of infection with S. hemolyticus was recognized on November 12 in a measles-pneumonia ward which had been opened for several weeks and had continued free from streptococcus. In three patients hemolytic streptococci were found by throat cultures. Inquiry revealed that a nurse in this ward, recognized as a streptococcus “carrier” the week before, had been retained on duty. Two patients well advanced in the course of their pneumonias, had acquired S. hemolyticus demonstrated by throat examination. Both patients developed otitis media with mastoid extension requiring operations. Cultures from both at operation showed hemolytic streptococci.

The third patient, with acute pneumonia, had been sent into the ward on November 11 from Ward 42, which at the time was a highly infected ward; no culture of the throat was made before transfer. This patient developed streptococcus pneumonia with empyema requiring subsequent operation.

Discussion.—At Camp Funston, where the prevalence of S. hemolyticus in the measles wards did not rise above that among normal men in the camp at large, 112 consecutive cases of measles were treated without a single complication due to hemolytic streptococci.

At Camp Pike, the investigation began at the onset of a small epidemic of measles at a time when hemolytic streptococci were an almost negligible factor. The epidemic of measles was followed throughout its course; and, with the passing of the epidemic, there was an increase in the prevalence of hemolytic streptococci which assumed alarming importance in the production of complications.

The epidemic of measles was in part superimposed upon the epidemic of influenza, so that deductions concerning complications strictly due to measles became impossible. It is evident that influenza played a considerable part in producing the complications of measles at Camp Pike.

The dissemination of hemolytic streptococci through measles wards was controlled only in part by the methods used. This partial control may have served to limit the incidence of streptococcus pneumonia, nine instances occurring among 867 cases of measles.

In the ward treatment of measles effort should be directed to prevent the exposure of patients free from hemolytic streptococci to S. hemolyticus “carriers.” By this means the rate of development of S. hemolyticus “carriers” may be reduced.

Measures which should be adopted are as follows:

1. Adequate wards should be prepared in advance for the treatment of measles. The rather gradual onset of epidemics of measles makes this provision possible.

2. The separation of S. hemolyticus “carriers” from other patients should be enforced. Observation wards, where strict technic to prevent transfer of infection is practiced and where throat cultures are made on admission, are essential. Those wards should be promptly evacuated to wards for the care of S. hemolytic “carriers” on the one hand and for “noncarriers” on the other. As far as possible patients should be admitted to a ward until it is filled and then another ward should receive consecutive cases in the same manner. It is desirable to have all cases in each treatment ward in the same stage of the disease. With this system of ward rotation convalescent wards are necessary, so that cases requiring a period of hospitalization longer than the average may be segregated, thus rendering treatment wards available for another levy of acute cases.

3. Strict ward technic elaborated to prevent transfer of bacterial infection from one patient to another must be employed.

4. Throat culture for identification of “carriers” is laborious but essential. An accurate method for identifying and reporting “carriers” as speedily as possible must be employed. A competent bacteriologist is essential. A twenty-four hour interval between culture and its report is desirable. The following scheme is recommended:

(a) A culture from the throat made on admission to the observation ward (first day in hospital).

(b) A culture made on the first day in the treatment ward (third day in hospital).

(c) A culture made one week later (tenth day in hospital).

If the ward incidence of hemolytic streptococci reaches 10 per cent, especially in a filled ward, the cultures should be repeated on the thirteenth day in the hospital. If the incidence of “carriers” of hemolytic streptococci increase rapidly, cultures on alternate days should be made so that “carriers” may be removed from the ward. Wherever possible, culturing of the treatment wards as units should be practiced.

5. Patients developing acute symptoms in any way suggestive of infection with S. hemolyticus should be immediately isolated; culture from the throat should be made at once and final disposal of the patient should depend upon its result.

Carriers of Hemolytic Streptococci

During the winter of 1917–18, with the establishment of the army camps, it very soon became evident that in many of the serious and fatal complications of measles and other respiratory diseases, hemolytic streptococci were playing a very important rôle. The epidemic prevalence of hemolytic streptococci among hospital cases, and later among men on duty in the camps, was established by bacteriologic studies. Prior to this time in civil life, hemolytic streptococci under epidemic conditions had been studied in milk-borne epidemics of septic sore throat, such as are reported from Chicago in 1911–13^[92]; from Boston in 1911^[93]; and from Baltimore in 1911–12^[94]. Contact air-borne infection has not been emphasized in considering the dissemination of hemolytic streptococci. Smillie^[95] reports a few cases of hemolytic streptococcus throat infections which he attributes to contact infection. Conditions within the army camps were such as to suggest the dissemination of hemolytic streptococci by contact air-borne infection. Some knowledge of the percentage of individuals showing positive throat cultures became desirable at the very beginning of studies of contact dissemination of hemolytic streptococci.

Smillie found that only one of 100 normal throats harbored the Beta hemolytic streptococci of Smith and Brown. Levy and Alexander^[96] report the presence of hemolytic streptococci in 83.2 per cent of healthy men at Camp Taylor, and hemolytic organisms (not definitely identified as streptococci) in 14.8 per cent of recruits arriving at Camp Taylor. Irons and Marine^[97] found hemolytic streptococci among 70 per cent of healthy men at Camp Custer.

Among measles patients on admission to the hospital at Fort Sam Houston, Cole and MacCallum^[98] report 11.4 per cent and Cummings, Spruit and Lynch,^[99] 35 per cent of throat cultures positive for hemolytic streptococci. At Camp Taylor, Levy and Alexander report 77.1 per cent positive among 388 cases of measles on admission to the hospital.

The spread of hemolytic streptococci in measles wards was shown by Cole and MacCallum when on admission 11.4 per cent of cases had positive throat cultures, 38.6 per cent after from three to five days, and 56.8 per cent after from eight to sixteen days in the ward. In our study of hemolytic streptococci with measles at Camp Funston, 2.6 per cent of the cases had positive throat cultures on admission, 12.8 per cent after three to ten days, and 24.1 per cent after eight to twenty-three days in the hospital. In a similar study at Camp Pike we found 1.7 per cent positive on admission; 10.9 per cent after one week; 22.8 per cent after two weeks; 26.2 per cent after three weeks; and, 33.1 per cent after four weeks in the hospital.

Hemolytic Streptococci in the Throats of Normal Men.—The percentage of normal individuals harboring hemolytic streptococci in their throats was investigated in three distinct classes of men, classified according to the degree of exposure to contact infection.

The first group includes men largely from country districts, cultured within an hour after being assembled by their local draft board. The laboratory car “Lister” was sent to Hot Springs, Ark. to meet the November draft of men to be sent to Camp Pike. These men were returned to their homes when the armistice was signed, so that there was no opportunity to study them after they had lived under camp conditions.

The second group includes men on duty in Camps Funston and Pike. These men, while largely from country districts, had been living crowded together in the camp for a period varying from a few weeks to several months.

The third group includes normal men resident in the base hospitals at Ft. Riley and Camp Pike. This group includes at Camp Pike the medical personnel of the measles and measles pneumonia wards and represents individuals most exposed to contact infection with hemolytic streptococci. On the other hand, the group includes doctors, nurses and seasoned medical detachment men who are perhaps less susceptible to respiratory infections than are raw recruits.

The results of studies of these groups are presented in Tables LXVI and LXVII.

The group of men studied at Hot Springs represents individuals among whom there was little chance for contact dissemination of hemolytic streptococci. It is a control series of men from outlying districts examined before their throat bacteriology has been complicated by the interchange of mouth organisms which occurs when a group of men are crowded into close quarters. The entire absence of hemolytic streptococci by the throat culture method is noteworthy. By multiplying the chances of identifying hemolytic streptococci by making parallel cultures from the saliva, and from the peritoneal exudates of mice inoculated with saliva, hemolytic streptococci were found, in small numbers, in 3 instances. The findings in this group were only three throats lightly infected with hemolytic streptococci. They are in direct contrast with the findings among individuals living in camps under crowded conditions and are in accord with the findings among recruits arriving in camp as recorded by Levy and Alexander.

In the second group, men living for a time in camp, the findings at Camp Funston and at Camp Pike show rather striking differences. The lower percentage incidence at Camp Pike is the more remarkable since the studies were made soon after the influenza epidemic had swept the camp and made necessary the hospitalization of about 20 to 25 per cent of the camp population.

In the third group, namely, individuals resident in the hospital, percentage rates at Camp Funston are slightly higher than for men resident in camp. This difference disappears for the entire group at Camp Pike if we consider a single throat culture, as we must for the sake of comparison. The majority of these individuals at Camp Pike served in measles wards from which patients carrying hemolytic streptococci were removed at weekly intervals. Seven and one-half per cent of the ward personnel were positives when first cultured. An additional 7.5 per cent acquired the streptococcus while under observation.

Duration of the “Carrier” State.—Unfortunately there are very few observations with regard to the duration of the “carrier” state which can be determined only by repeated cultures at short intervals. We have made no observations of the duration of the “carrier” state in healthy men. Two hundred and forty-two individuals carrying hemolytic streptococci were identified in the ward treatment of measles. All except 37 of these cases were “noncarriers” when first observed. The remaining 205 include 166 contact “carriers” and 39 patients with acute symptoms of infection by hemolytic streptococci.

The complete record of throat cultures on these cases is presented in Table LXVIII.

Group I includes 37 cases positive for hemolytic streptococci on admission.

(a) Twenty-two of these remained positive throughout the period of observation. Four patients became negative after one or two weeks and later showed positive findings, leaving the hospital as positives. These are classified as “irregular.” The results of culture were as follows: Cultured once only, 7; positive after one week, 7; positive after two weeks, 6; positive after three weeks, 2; irregular, 4.