Epidemic Respiratory Disease / The pneumonias and other infections of the repiratory tract accompanying influenza and measles

by Eugene L. Opie; Francis G. Blake; Thomas M. Rivers; James C. Small

Secondary Infection with S. Hemolyticus in Pneumonia

Pneumonia caused by streptococci was repeatedly observed[^[50]] during the pandemic of influenza which occurred in 1889–90. With clearer recognition of the characters which distinguish varieties of streptococci several observers have shown that secondary infection with hemolytic streptococci may occur during the course of pneumonia and though definite evidence has been lacking have suggested that it may be acquired within hospital wards. That a similar secondary infection with S. hemolyticus in pneumococcus pneumonias following influenza occurred not infrequently at Camp Pike during the epidemic was shown by bacteriologic studies made during life and at autopsy in a considerable series of cases. During the early days of the epidemic of influenza, secondary streptococcus infection was almost entirely limited to certain wards which were opened for the care of the rapidly increasing number of patients with pneumonia. During this period these wards were overcrowded, organization was incomplete, and the opportunities for transfer of infection from patient to patient were almost unlimited. The spread of streptococcus contagion and its fatal effect may be clearly brought out by comparison of these wards with wards that had long been organized for the care of patients with pneumonia.

Ward 3 had been in use for the care of patients with pneumonia for some time prior to the outbreak of influenza. It was provided with sheet cubicles and conducted by medical officers, nurses and enlisted men accustomed to the care of patients with pneumonia, ordinary precautions being taken against transfer of infection from one patient to another. The data in Table XVII show the average number of patients in the ward, the number of new cases of pneumonia admitted, and the number of deaths among patients admitted during the corresponding period, for three periods of ten days each from September 6 to October 5. The types of infection in fatal cases as determined by cultures taken at autopsy are also shown.

Table XVII
Pneumonia in Ward 3
	AVERAGE NUMBER OF PATIENTS IN WARD	NUMBER OF PATIENTS ADMITTED	TOTAL DEATHS AMONG PATIENTS ADMITTED DURING THE CORRESPONDING PERIOD		CULTURES AT AUTOPSY
			NUMBER	PER CENT	PNEUMOCOCCUS	S. HEMOLYTICUS	UNDETERMINED (NO AUTOPSY)
Sept. 6–15	18.6	11	3	27.2	3	0	0
Sept. 16–25	46.1	52	16	30.7	13	1	2
Sept. 26–Oct. 5	58.6	23	8	34.7	5	1	2

During the period from September 6 to 15, just prior to the outbreak of influenza in epidemic proportions, the ward had an average population of 18.6 patients. The total number of new patients admitted was 11, of whom 3 died, a mortality of 27.2 per cent. All these cases were pneumococcus pneumonias as determined by bacteriologic examination of the sputum at time of admission. The 3 fatal cases showed pneumococcus infection at autopsy. During the second period, from September 16 to 25, with the outbreak of the epidemic of influenza, the ward rapidly filled with new cases of pneumonia, attaining an average population of 46.1 patients. Of the 52 new cases admitted 16 died, a mortality of 30.7 per cent. Again all the cases admitted during this period in which bacteriologic examination of the sputum was made, were found to be pneumococcus pneumonias with one exception. This case, admitted on September 21 and dying two days later, had a hemolytic streptococcus pneumonia. Fortunately, though quite by accident, he was placed in a bed at one end of the porch and no transmission of streptococcus infection to other cases in the ward took place. At autopsy 13 cases showed pneumococcus infection; the foregoing case, hemolytic streptococcus. During the third period from September 26 to October 5 the ward became even more crowded, having an average of 58.6 patients; 23 new cases were admitted, 8 of whom died, a mortality of 34.7 per cent. Autopsy showed that 5 of these were pneumococcus pneumonias and 1 was caused by hemolytic streptococcus infection. It is noteworthy that the death rate from pneumonia gradually increased as the ward became more and more crowded. This may possibly be attributed in part to the increasing severity of the pneumonia during the early days of the influenza epidemic. That it was in part directly due to secondary contact infection with pneumococcus will be shown when the transmission of pneumococcus infection is discussed. In spite of the overcrowding of the ward the introduction of 2 cases of streptococcus pneumonia did not cause an outbreak of streptococcus infection. Whether this was due to precautions taken against the transfer of infection or was merely a matter of good luck is difficult to say, in view of the fact that a considerable amount of transfer of pneumococcus infection from one patient to another did occur.

Ward 8 had long been used for the care of colored patients with pneumonia. As in Ward 3 cubicles were in use and ordinary precautions against the transfer of infection were used. The data are presented in Table XVIII.

Table XVIII
Pneumonia in Ward 8
	AVERAGE NUMBER OF PATIENTS IN WARD	NUMBER OF PATIENTS ADMITTED	TOTAL DEATHS AMONG PATIENTS ADMITTED DURING THE CORRESPONDING PERIOD		CULTURES AT AUTOPSY
			NUMBER	PER CENT	PNEUMOCOCCUS	S. HEMOLYTICUS	UNDETERMINED (NO AUTOPSY)
Sept.
6–20	25.5	18	2	11.1	2	0	0
Sept. 21–Oct. 5	46.1	59	20	33.9	10	1	9

During the period from September 6 to 20, prior to the outbreak of influenza in epidemic proportions among the colored troops, the ward had an average population of 25.5 patients; 18 new cases of pneumonia were admitted during this period, all of whom were pneumococcus pneumonias as determined by bacteriologic examination of the sputum at time of admission to the ward. Only 2 died, a mortality of 11.1 per cent, autopsy cultures showing pneumococcus in both cases. All these patients were treated on the porch of the ward while they were acutely sick. During the second period from September 21 to October 5, when the influenza epidemic was at its height, the ward rapidly filled with active cases of pneumonia and became distinctly crowded. It contained an average of 46.1 patients, but had actually reached a population of 64 patients at the end of the period. Of the 59 new cases admitted, 20 died, a mortality of 33.9 per cent, 10 with pneumococcus pneumonia, one with hemolytic streptococcus pneumonia. In 9 there was no autopsy. The conditions in Ward 8 were quite analogous to those in Ward 3. In spite of the overcrowding during the second period no outbreak of secondary infection with S. hemolyticus occurred, but secondary pneumococcus infection did occur as will be shown below.

In contrast with these two wards are Wards 1 and 2 in which widespread secondary contact infection with S. hemolyticus took place. Ward 2 was opened September 26, at the beginning of the period when 20 new wards for pneumonia were organized. From September 26 to October 1 the cubicle system was not in use, the ward was crowded, organization was imperfect, and few precautions were taken to prevent transfer of infection from one patient to another. On October 2 the cubicle system was installed and precautions against transfer of infection were instituted. The data are shown in Table XIX.

Table XIX
Pneumonia in Ward 2
	AVERAGE NUMBER OF PATIENTS IN WARD	NUMBER OF PATIENTS ADMITTED		TOTAL DEATHS AMONG PATIENTS ADMITTED DURING THE CORRESPONDING PERIOD		CULTURES AT AUTOPSY
				NUMBER	PER CENT	PNEUMOCOCCUS	S. HEMOLYTICUS	UNDETERMINED (NO AUTOPSY)
Sept. 26	10	10	40	27	67.5	0	23	4
Sept. 27	27	17
Sept. 28	40	13
Sept. 29	51	12	17	6	35.3	2	2	2
Sept. 30	49	1
Oct. 1	43	4
Oct. 2	47	6	10	4	40.0	2	1	1
Oct. 3	42	0
Oct. 4	41	4

During the first three days 40 patients with pneumonia were admitted to the ward. Of these 40 patients, 27 died, a mortality of 67.5 per cent. Cultures at autopsy showed that 23 of these died with hemolytic streptococcus infection, none of pneumococcus infection. In four there was no autopsy. To appreciate the full significance of these figures it must be emphasized that these patients at time of admission to the ward in no way differed from those admitted to Ward 3 during the corresponding period and were not in any sense selected cases. The type of infection in 9 of these patients had been determined by bacteriologic examination of the sputum just prior to or immediately after admission to the ward before opportunity for secondary contact infection in this ward had occurred. All 9 were shown to have pneumococcus pneumonia free from hemolytic streptococci at that time. All 9 died, 7 with secondary streptococcus infection as shown by cultures taken at autopsy, 1 with a secondarily acquired Pneumococcus Type III infection—sputum showed a Pneumococcus Type IV on admission—and in 1 there was no autopsy. In view of the fact that bacteriologic examination of the sputum in cases of pneumonia following influenza had shown that the large majority of them were due to pneumococcus infection, it is probable that most of the other cases of pneumonia admitted to this ward were pneumococcus pneumonias at time of admission, and that they acquired the streptococcus infection after admission.

During the next three days 17 new patients were admitted, of whom 6 died, a mortality of 35.3 per cent. Cultures at autopsy showed pneumococcus infection in 2, streptococcus in 2. It is noteworthy that the porch was first put into use on September 29. Of the 12 patients admitted on this date, 8 were treated throughout the acute stage of their illness on the porch. Of these 8 patients but one died, of a Pneumococcus Type IV infection and none became infected with S. hemolyticus. From October 4 to October 6, 10 patients were admitted, of whom 4 died. Cultures at autopsy showed pneumococcus infection in 2, hemolytic streptococcus in 1.

The widespread prevalence of hemolytic streptococcus infection in this ward as compared with its almost entire absence in Wards 3 and 8 is very striking. Cultures made during life and at autopsy have shewn clearly that it was due to rapid spread of contagion throughout the ward. The almost unlimited opportunities for transfer of infection from patient to patient, during the first six days the ward was in use, undoubtedly greatly facilitated this spread. From the data available it is impossible to state exactly when and by which patients hemolytic streptococcus infection was introduced into the ward, but it must have been very early since the death rate was very high from the beginning, and the first 23 cases coming to autopsy died with streptococcus infection.

Ward 1 was opened on September 24. From that date until October 2 no cubicles were in use and few precautions were taken against transfer of infection. On October 2 cubicles were installed and ordinary precautions to prevent transfer of infection were instituted. On October 6 the ward was closed to further admissions. The data presented in Table XX are divided into two periods, because on September 29 and 30, 4 patients with streptococcus pneumonia were admitted to the ward.

Table XX
Pneumonia in Ward 1
	AVERAGE NUMBER OF PATIENTS IN WARD	NUMBER OF PATIENTS ADMITTED	TOTAL DEATHS AMONG PATIENTS ADMITTED DURING THE CORRESPONDING PERIOD		CULTURES AT AUTOPSY
			NUMBER	PER CENT	PNEUMOCOCCUS	S. HEMOLYTICUS	UNDETERMINED (NO AUTOPSY)
Sept. 24–29	35.8	34	11	32.3	5	3	3
Sept. 30–Oct. 5	55.3	40	24	60.0	6	14	4

During the first period from September 24 to 29 the ward contained an average of 35.8 patients, being only moderately crowded; 34 cases of pneumonia were admitted, of whom 11 died, a mortality of 32.3 per cent. It is noteworthy that deaths among this group which occurred prior to September 30 were due to pneumococcus infection with one exception, a patient entering the ward on September 26 and dying the following day. Of the other 2 patients in this group who died with hemolytic streptococcus pneumonia, 1 was admitted to the ward on September 25, was shown to be free from S. hemolyticus on September 30, and died on October 12 with a secondarily acquired streptococcus pneumonia and empyema; the other was admitted on September 29 with streptococcus pneumonia and died the following day.

During the second period from September 30 to October 5 the ward contained an average of 55.3 patients, being very overcrowded; 40 new cases of pneumonia were admitted of whom 24 died, a mortality of 60 per cent. Cultures taken at autopsy showed that 6 died of pneumococcus pneumonia, 14 with hemolytic streptococcus infection. As in Ward 2, patients admitted to this ward were in no way selected and were probably, as experience has shown, in large part pneumococcus pneumonias at time of admission. The widespread dissemination of hemolytic streptococcus and its fatal effect following the introduction of the organism on September 29 and 30 is only too evident.

Table XXI
Secondary Infection with Pneumococcus Type II
NAME	BED OCCUPIED	ADMITTED	PNEUMOCOCCUSIN SPUTUM ON ADMISSION	SECONDARY INFECTION
				DATE	PNEUMOCOCCUS AT AUTOPSY
Pvt. Wolfe	No. 6	Sept. 17	IV	Sept. 23	II[[51]]
Pvt. Pullam	No. 5	Sept. 9	IV	Sept. 24	II
Pvt. Swain	No. 3	Sept. 16	II