| Table VII | ||||||
|---|---|---|---|---|---|---|
| Incidence of B. Influenzæ in Normal Men as Determined by Intraperitoneal Inoculation of White Mice With Saliva or Sputum | ||||||
| DATE | PLACE | ORGANIZATION | NUMBER EXAMINED | B. INFLUENZÆ PRESENT | PER CENT POSITIVE FOR B. INFLUENZÆ | REMARKS |
| 1918 | ||||||
| Aug. 13 | Camp Funston, Kans. Detention Camp, No. 2 | 22 Prov. Colored Co. 164th Depot Brigade | 25 | 6 | 24 | Bronchitis and pneumonia were prevalent in this organization of recently drafted negroes during July and August, 1918 |
| Aug. 18 | Camp Funston, Kans. Detention Camp, No. 2 | Co. D. 3rd Dev. Bn. | 25 | 11 | 44 | Recently drafted southern negroes not fit for full military duty. Bronchitis and pneumonia were prevalent in this organization during July and August, 1918 |
| Aug. 20 | Camp Funston, Kan. | 70th Inf. | 25 | 11 | 44 | 25 men presenting themselves at sick call for various complaints; not strictly normal; respiratory diseases not prevalent |
| Aug. 22 | Ft. Riley, Kan. | Quarters 4 M M.O.T.C. | 32 | 16 | 50 | Recently drafted white men of 4 to 8 weeks’ service. Pneumonia fairly prevalent in this organization |
| Aug. 26 | Camp Funston, Kan. | 210th Eng. | 27 | 3 | 11.1 | About one mile distant from Camp Funston proper. No sickness in this organization |
| Nov. 12 | Hot Springs, Ark. | Drafted men assembled to entrain for camp | 50 | 11 | 22 | 50 men selected from isolated farm communities; 12 gave a history of “influenza” within the preceding 8 weeks |
| Nov. 25 | Camp Pike, Ark. | Miscellaneous | 26 | 13 | 50 | 12 of this group had influenza during the epidemic |
| Dec. 10 | Camp Pike, Ark. | Miscellaneous | 25 | 17 | 68 | 12 of this group had influenza during the epidemic |
| Summary: | Normals | 235 | 88 | 37.4 | ||
| Cases of influenza (for comparison) | 76 | 61 | 80.3 | |||
On November 12 search was made for B. influenzæ in 50 normal drafted men who had assembled at Hot Springs, Ark., on that date preparatory to entraining for Camp Pike. These men were all from isolated farming communities where influenza was only moderately prevalent and where there was little opportunity for the wide dissemination of B. influenzæ such as occurs when large bodies of men are assembled in camps. Twelve of the 50 gave a history of influenza within the preceding eight weeks. The cultures were made by the same methods as those used at Camp Pike, the laboratory car “Lister” being taken to Hot Springs for that purpose. The incidence of B. influenzæ was only 22 per cent. In striking contrast with this figure are the figures of 50 and 68 per cent obtained in the last two groups studied at Camp Pike after the epidemic had swept through the camp: 24 of the 51 men in these groups had influenza during the epidemic.
It is of interest to record that the incidence of pneumococcus in these cases was approximately the same in all groups and bore no relation to the prevalence of influenza, bronchitis, or pneumonia.
| Table VIII | ||||||
|---|---|---|---|---|---|---|
| Incidence of B. Influenzæ in Normal Men as Determined by Throat Cultures on Blood Agar Plates | ||||||
| DATE | PLACE | ORGANIZATION | NUMBER EXAMINED | B. INFLUENZÆ PRESENT | PER CENT POSITIVE FOR B. INFLUENZÆ | REMARKS |
| Sept. 14–Oct. 5 | Camp Pike, Ark. | Med. Detachment, Base Hos.; personnel on measles wards | 82 | 14 | 17.1 | 82 throat cultures in 42 individuals |
| Nov. 5–9 | Camp Pike, Ark. | Miscellaneous | 296 | 71 | 23.9 | Number among this group who had had influenza not recorded |
| Nov. 12 | Hot Springs, Ark. | Drafted men assembled to entrain for camp | 64 | 0 | 0 | Men, in large part from isolated farm communities; 13 gave a history of “influenza” within the preceding 8 weeks |
| Nov. 25 | Camp Pike | Miscellaneous | 26 | 13 | 50 | 12 of this group had influenza during the epidemic |
| Dec. 10 | Camp Pike | Miscellaneous | 25 | 13 | 52 | 12 of this group had influenza during the epidemic |
| Summary | Normals | 493 | 111 | 22.5 | ||
| Cases of influenza (for comparison) | 166 | 109 | 65.7 | |||
The results obtained by throat culture are quite similar to those obtained by the mouse inoculation method. The entire absence of B. influenzæ in the group of 64 throat cultures made in the draft men assembled at Hot Springs as compared with the relatively high incidence in the last two groups examined at Camp Pike is very striking.
In consideration of the figures presented in Table IX it is important to remember that the group of 50 men from Hot Springs were all from isolated farm communities, had not previously been assembled and had not been in continuous contact with a widespread epidemic of influenza. On the other hand, the two groups of normal men at Camp Pike were studied immediately after the epidemic had swept through the camp and had been constantly in contact with epidemic influenza for a period of three months, 24 of the 51 actually having had the disease during this period. The fact that in the group of men from Hot Springs, B. influenzæ was found only by the mouse inoculation method is noteworthy, since it indicates that the organism was present in relatively small numbers and could be detected only by a highly selective method.
| Table IX | ||||||||
|---|---|---|---|---|---|---|---|---|
| Incidence of B. Influenzæ in Normal Men Contrasted With That in Early Cases of Influenza as Determined by Multiple Cultures from Nose, Throat, and Sputum | ||||||||
| DATE | PLACE | GROUP | NUMBER EXAMINED | PER CENT SHOWING B. INFLUENZÆ | ||||
| NOSE | THROAT | SPUTUM DIRECT CULTURE | SPUTUM MOUSE INOCULATION | BY MULTIPLE CULTURES | ||||
| Nov. 12 | Hot Springs, Ark. | Normal draft men assembled to entrain for camp | 50 | 0 | 0 | 0 | 22 | 22 |
| (4 cultures only) | (31 cultures only) | |||||||
| Nov. 25 | Camp Pike | Normal men; 12 had influenza during the epidemic | 26 | 38.6 | 50 | 34.6 | 50 | 80.8 |
| Dec. 10 | Camp Pike | Normal men; 12 had influenza during the epidemic | 25 | 48 | 52 | 24 | 68 | 88 |
| Oct. 10 and Nov. 19 | Camp Pike | Patients with influenza in Base Hos. | 28 | 21.4 | 50 | 60.7 | 78.6 | 100 |
Summary of the results obtained in normal men shows that the incidence of B. influenzæ in normal individuals from isolated communities or in groups free from respiratory diseases prior to the occurrence of the fall epidemic was relatively low, namely, 10 to 20 per cent; that in observations made before the fall epidemic in groups in which “bronchitis” and pneumonia were fairly prevalent, B. influenzæ was found much more frequently, namely, in 25 to 50 per cent of the cases; and that in groups studied at intervals during the epidemic the incidence of B. influenzæ rapidly rose, reaching 85 per cent at the end of the epidemic. In contrast with this, B. influenzæ was found in 100 per cent of cases of influenza without reference to the time at which they occurred during the epidemic. It is obvious that the high percentage of normal men carrying B. influenzæ found at the end of the epidemic can depend only on the wide dissemination of B. influenzæ that must occur during epidemic times.
Bacillus Influenzæ in Measles.—Since the presence of B. influenzæ in other diseases than influenza has been advanced as an argument against its causal relationship to influenza, an extensive study of the incidence of B. influenzæ in the throats of measles patients was made during the period of the epidemic of influenza at Camp Pike from September 10 to October 20. In all a total of 830 throat cultures in 487 cases of measles were made, many cases being cultured repeatedly at weekly intervals. The results have been condensed as far as possible and are presented in Tables X, XI, XII.
| Table X | |||
|---|---|---|---|
| Incidence of B. Influenzæ in 400 Consecutive Cases of Measles as Determined by Throat Culture at Time of Admission to the Base Hospital | |||
| DATE | NUMBER OF CASES | B. INFLUENZA FOUND | |
| NUMBER | PER CENT | ||
| Sept. 16–Oct. 4 | 100 | 27 | 27 |
| Oct. 4–Oct. 10 | 100 | 32 | 32 |
| Oct. 10–Oct. 15 | 100 | 32 | 32 |
| Oct. 15–Oct. 19 | 100 | 48 | 48 |