In this series of cases lesions elsewhere in the body are not
sufficiently constant or important to merit emphasis.[13] Hemorrhages
have been found occasionally in other structures, especially the testes.
The usual cloudy swelling of the parenchymatous organs is, of course,
marked, and in many cases has been associated with actual cellular
necrosis both in the liver and the kidney. Such necroses are usually
focal, and occasionally mitotic figures in the cells of the renal
convoluted tubules or in the liver may be a similar expression of
previous damage. Acute nephritis was not found in our series.[14] The
swollen liver cells often show the bile canaliculi clearly, and this
appearance may be associated with a variable degree of jaundice which
has been found frequently, although the explanation of the jaundice is,
in all probability, an hemolysis of the red cells caused by the
infecting microorganisms. The only other lesion encountered and of
sufficient importance to mention, has been the congestion of the
membranes of the brain and a swelling of the cerebral substance, in all
probability dependent upon edema. One example of purulent meningitis was
encountered.[15] The dilatation of the right side of the heart with a
greater or lesser degree of splanchnic engorgement is such a common
feature in acute pulmonary diseases that it is hardly worthy of detailed
discussion.
[Illustration:
FIG. XXXVI. AUTOPSY NO. 133. A SMALL ABSCESS IN AN EDEMATOUS BAND OF
INTERLOBULAR CONNECTIVE TISSUE.
]
[Illustration:
FIG. XXXVII. AUTOPSY NO. 114. ILLUSTRATES AN UNUSUAL ANATOMICAL
PICTURE IN INFLUENZA—AN EXTENSIVE FIBRINOPURULENT PLEURISY. THE
BRONCHIAL LYMPH GLANDS ARE PROMINENT ON ACCOUNT OF THE HEMORRHAGIC
INFLAMMATORY PROCESS WHICH HAS INVOLVED THEM.
]
A striking feature of influenza is the occurrence of abortion in cases
complicated by pregnancy. Of the ninety-five cases included in this
report, twenty-seven were women of whom three died undelivered (three
months, six months, term), three had suffered complete abortion (one,
three months, and two, six months), and one (six months) was in process
of abortion. It is not our purpose to discuss the relation between
pregnancy and this complication. Here it is desirable simply to point
out that, although in the non-complicated cases of influenza, pregnancy
does not influence the course of the disease, if pneumonia supervenes,
the mortality for the mother, as well as for the child, is definitely
increased (57, 148, 164).
A specific placental lesion would be difficult, indeed, to establish
since hemorrhage is a part of the normal process of placental
separation. However, the hemorrhagic lesion of influenza seems a
plausible explanation for the frequency of abortions in this disease.
_Summary._
The most important extrapulmonary lesions in influenza are those of the
hematopoietic and the vascular systems. The first are typical of a
general non-suppurative, inflammatory process, and are characterized in
the majority of cases by a picture not unlike that encountered in
typhoid fever, although the hyperplasia of the lymphadenoid tissues, as
seen in the latter disease, is not present. The more important lesions
are associated with the vascular system; phlebitis and arteritis occur,
but are not so frequent as hemorrhages in the skeletal system, in the
parenchymatous organs, and in the mucous membranes of the hollow
viscera. These hemorrhagic necroses may be etiologically associated with
capillary bacterial thrombi.
IV. COMPARISON BETWEEN THE RESPIRATORY LESIONS OF INFLUENZA AND THOSE
INITIATED BY THE INHALATION OF POISONOUS GASES
Immediately preceding the advent of the influenza epidemic in New Haven,
there had been completed in this laboratory the experimental studies of
the effects of a large number of different toxic gases upon the
respiratory tract. This was begun with the support of the Bureau of
Mines, and subsequently, after the formation of the Chemical Warfare
Service, the work received the support, not only of this branch of the
Army, but also of the Surgeon General’s Office. Exceptional
opportunities for animal experimentation were offered. Every stage of
the inflammatory process in the respiratory tract was studied, from the
most acute, a few hours after the exposure of the animal to a high
concentration of gas, to the very chronic types that resulted from
sublethal concentrations and led to lesions encountered at the sacrifice
of the animals many months later.
The criticism will unquestionably be introduced, that with the
anatomical picture of the respiratory lesions initiated by irritating
gases freshly in mind, an analogy between them and those of the
pulmonary lesions of influenza may not be impartially drawn. However,
such fundamental and striking similarities exist between the two
processes (128) that the argument is simplified.