Infections of the eye by the influenza bacillus are quite common. This subject is fully discussed by Axenfeld (text-book, “The Bacteriology of the Eye”). Giani and Picchi found it in the eye in 66 per cent. of influenza cases, in 90 per cent. of epidemic conjunctivitis, and in the normal eye of 5.8 per cent. Wynekoop, in 1903, reported having found this organism in cases of conjunctivitis in 1899. Guiral, in the recent epidemic, found influenza bacillus constantly present in the secretions in cases of what seemed to be Week’s conjunctivitis. Ulceration of the cornea was rather common. One such case is mentioned in which there was no pain in the eyes, but general symptoms of influenza. The middle ear is also sometimes infected. Between the report of Kossel in 1893 and that of Stone and Swift in 1918, who found the middle ear and mastoid to contain B. influenzæ in 8 of 17 cases, there have been many references in the literature to this complication by the influenza bacillus. The evidence indicates, however, that in the middle ear, as in the pleural cavity, the secondary bacteria are far more often the important ones.
Meninges
Influenzal meningitis seems to stand by itself as a manifestation of the pathogenic effects of B. influenzæ. The literature is too voluminous to review in this place, but the evidence would seem to point to a more invasive and pathogenic type of this organism, if not to a separate member of the group.
Invasion of the Blood Stream
The evidence in clinical influenza would suggest at times a bacteremia in addition to the severe toxemia, which is such a constant feature of the disease. Simultaneously with the discovery of B. influenzæ, Canon reported finding bacilli of similar morphology in blood smears, but was unable to grow them, and it would appear at least doubtful that he was dealing with the influenza bacillus. Meunier is probably the first who grew this organism from the blood. He recovered it from 8 blood cultures out of 10 in cases of broncho-pneumonia following measles, and in one other case of broncho-pneumonia. A very full discussion of this question is to be found in Canon’s book on “The Bacteriology of the Blood in Infectious Diseases.” Of particular interest are the results of Ghedini, who made a careful study of 28 influenza patients. B. influenzæ was grown from the blood in 18 of these at the height of the fever, while in the 10 negative cases the disease was milder or the blood was taken only after the temperature had fallen. The amount of blood used was 20-30 c.c., and it was cultured in lecithin broth. In practically all of his cases several cultures were taken, and in a number of the positive cases negative results were obtained both before and after the acme of the fever. He also grew the bacillus from 8 of 14 spleen punctures of these patients. Madison (1910) reported the recovery of this bacillus from the blood of a patient with a primary broncho-pneumonia who recovered. This author also used about 30 c.c. of blood. Thursfield, in 1910, also reported two cases of B. influenzæ bacteremia in which the organisms were recovered at the height of the temperature. One had influenza, the other phlebitis, and both recovered. Tedesko and several others have found it in the heart’s blood in many cases, more especially in broncho-pneumonia after measles.
During the present epidemic the positive cultures of this bacillus from the blood have been rather infrequent. J. S. Fleming had 2; 2 are quoted in the report of the Influenza Committee of the Advisory Board to the D. G. M. S. (Peters and Cookson); Medalia had 2 during life and 19 of 34 at autopsy; Orticoni, Barbie and Leclerc in 5 of 10 blood cultures in one series, and 7 of 19 in another; Stone and Swift 2 at autopsy; McKeekin, in Australia, influenza-like bacilli in 4; Blanton and Irons three times in the heart’s blood, one of these pure; Spooner, Scott and Heath twice in the heart’s blood at autopsy, and Wollstein and Goldbloom from the heart’s blood in one child. In the majority of these findings the bacillus was not found in pure culture. Abrahams and his associates found the B. influenzæ along with a pneumococcus and M. catarrhalis from the heart’s blood in one case. In our positive blood culture there was evidence of the same mixture being present.
Before drawing sweeping conclusions against the invasion of the blood by B. influenzæ it must be remembered that the quantity of blood used has been generally only about 10 c.c., and often much less, the difficulty of observing growth if the culture is pure has been largely overlooked, the use of more favorable media than blood agar and the possible inhibitory action of influenzal blood, as suggested by Wittingham and Sims, Rivers and others, has not been considered, and further that sufficient care has not been exercised to obtain blood at the most favorable period in the disease. It may be recalled that the problem is quite similar to that of demonstrating the organisms in the blood in patients with streptococcus viridans bacteremia.
All the available evidence, however, points to the invasion of the blood in influenzal infections as being a very fleeting one. Unless this is true, it would be surprising in the many hundreds of blood cultures which have been taken in the concentrated study of patients during the recent pandemic, if more successful cultures had not been obtained. General infections with localization of B. influenzæ in different parts of the body are here of interest—such as that reported by Slawyk and others. Whether the strains causing meningitis, and which apparently more frequently invade the blood, are really different members of the hemophilic group or only forms with a higher invasive power is still, I believe, an open question.
Endocarditis
In endocarditis the B. influenzæ is probably, after streptococci, the organism most frequently isolated from the blood. Rosenthal from heart’s blood at autopsy, Schlangenhaufer, Jehle two cases, Horder (1907) six cases, and who believed he was the first to isolate B. influenzæ from the blood, Tedesko in a number at autopsy, Spat, F. J. Smith, Saathoff, Libman four cases, Sacquepee, McPhedran, Mann, Rainaford and Warren three cultures from two patients, and a number of others all bear witness to its frequency.