1238 



YELLOW FEVER 



is that the temperature does not decHne, the jaundice deepens, 

 haemorrhages appear under the skin, and from the regions indicated 

 above, hiccough, subsultus tendinum, clammy sweats, anuria, 

 coma, and convulsions lead to death, which may, however, take 

 place before the full development of these symptoms by cardiac 

 or respirator}^ failure. 



Varieties. — ^Three varieties may be recognized, though some 

 authors describe more. These are the mild, the severe, and the 

 malignant. The mild type consists of simply the first paroxysm, 

 in which the temperature does not rise above 102° F., the urine 

 contains albumen, and the fever ceases by crisis on the second or 

 third day. The severe type shows the characters given above as 

 typical for the disease. The malignant type begins with high fever, 

 105° to 107° F., with violent vomiting and the early appearance 

 of black vomit and melsena, when the patient quickly becomes 

 delirious, and dies in the initial fever. 



Complications, — ^Any pre-existing pathological condition is serious 

 in yellow fever, but renal and cardiac affections are perhaps the worst. 

 Gangrene, abscesses, congestion of the lungs, and intussusception 

 are possible complications arising in the course of the disease. 



Sequelae. — ^Boils and abscesses, dysentery and hepatitis, are the 

 common sequels, but usually convalescence is not complicated or 

 protracted. 



Prognosis. — ^The mortality is very variously given, usually 10 to 

 25 per cent, for the United States and Europe, and 45 to 80 per 

 cent, for the endemic area and West Africa. The extremes are 

 0*5 to 94*5 per cent. 



All cases of yellow fever must be considered serious, especially 

 if complicated with pre-existing disease, and constant care must 

 be taken to measure the daily quantity of urine passed, and to 

 estimate the amount of albumen; for marked diminution of the 

 urine, especially anuria, is a grave sign. High temperatures, black 

 vomit, melaena and other haemorrhages, and marked disturbance 

 of the nervous system, are all bad omens. 



According to Sternberg, if the temperature does not rise over 

 103° F. the prognosis is usually good. 



Diagnosis. — ^'fhe typical symptoms in an epidemic will hardly be 

 mistaken for any other disease, but the mild early case is very diffi- 

 cult to recognize. The best signs for a positive diagnosis are the 

 early albuminuria, the epigastric tenderness, and, later, the jaun- 

 dice, with Faget's sign, and the black vomit. 



Differential Diagnosis. — ^The most important diseases to differen- 

 tiate in the first stage are dengue, subtertian malaria, blackwater 

 fever, and relapsing fever. Dengue may be recognized by the 

 absence of albuminuria, the preliminary rash, and leucopenia; 

 subtertian malaria by the parasites in the blood, and in some cases 

 the typical four-hourly temperature chart; blackwater fever by the 

 haemoglobin in the urine and the mononuclear increase; relapsing 

 fever by the parasites in the blood and the leucocytosis. 



