The same authority has also noted that ships in Havana harbor lying about 400 yards from shore never become infected when the crew have not been ashore or where infected ships have not been anchored near by.
It is probable that they are carried aboard ships in connection with coaling or provisioning rather than blown aboard by prevailing winds.
Fig. 45.—Temperature chart of Yellow Fever. A, Mild case with recovery. B, Severe case showing the saddle-back temperature curve similar to that of dengue. C, Chart of fatal case of yellow fever.
Pathology and Morbid Anatomy
The toxic effects are chiefly borne by the liver and endothelial linings of the capillaries. The cloudy swelling of the liver cells obstructs the bile canaliculi, causing jaundice, and the more advanced fatty degeneration of these cells brings about disturbances caused by interference with the important liver functions. The degenerative changes in the endothelial cells lining the capillaries bring about the haemorrhages so much a feature of yellow fever.
The icterus is apt to be more marked after death, and is especially prominent about the neck and eyelids. Dutroulau considers the absence of icterus in a cadaver as negativing yellow fever.
The liver is of a boxwood or chamois skin color and on section is very oily. Haemorrhagic patches may be seen dotting the yellow cut surface.
A midzonal fatty degeneration of the liver cells may be noted in cases dying by the 4th and 5th day but later there is degeneration of the entire lobule.