26 



Careful examination of stained blood smears will show an absence 

 of the plasmodia in the former group and their presence in the latter ; 

 but while the absence of the plasmodium from the blood excludes 

 malaria in the first instance, its presence in cases of the second group 

 does not eliminate yellow fever from consideration. In these cases, 

 yellow fever sliould be excluded only after a careful study of the case. 

 Careful observation for several days after the adminstration of a few 

 doses of quinine, preferably subciltaneously a or intravenously, may 

 be necessary. The abrupt decline in the fever coincident with the 

 disappearance of the parasites from the circulation following the exhi- 

 bition of the quinine in the manner indicated, with absence of albumen 

 from the urine or its presence only as a trace, with no jaundice and no 

 tendency to hemorrhage, may generally be interpreted as probably 

 excluding yellow fever. The mere decline of the fever after the 

 administration of quinine without a previous examination of the blood 

 to determine the presence of the malarial parasite does not exclude, 

 yellow fever. 



Hemoglobinuria. fever. — This grave manifestation of malaria resem- 

 bles yellow fever in its abrupt onset, bilious symptoms, jaundice, and 

 albuminuria, but differs in being characterized by a rapid blood 

 destruction and enlargement and tenderness of the liver and spleen. 

 The blood destruction manifests itself by a reduction in the number 

 of the red corpuscles, low hemoglobin percentage, and by the red or 

 black color of the urine, due to the elimination of hemoglobin. 



Dengue. — The differentiation between well-marked types of dengue 

 and yellow fqver is a matter presenting no serious difficulty after the 

 first two or three days. The points of difference most to be relied 

 on are the presence of an eruption and the absence of jaundice in 

 dengue. Albuminuria, which is so .prominent a sign even in relatively 

 mild attacks of yellow fever, is slight and commonly altogether absent 

 in even quite sharp attacks of dengue. In the latter disease the per- 

 centage of the polymorphonuclear leucocytes is reduced whereas in 

 yellow fever it is more or less increased. 



When, however, we come to deal with cases that are ill-defined, 

 cases that present no eruption (or in which none has been detected), 

 in which jaundice is doubtful /or absent, and in which no albumin or 

 only a dubious trace of it can be detected, we encounter a very real 

 and serious difficulty in deciding as to which of the two diseases we 

 have before us. While it is of the very greatest importance to recog- 

 nize that we have no means of surely identifying individual cases of 



a The injection should be given into a muscle, not into the subcutaneous cellular 

 tissue. With good aseptic technique the intravenous injection is preferable. Give 

 1 gram (15 grains) of the bimuriate dissolved in 1 cc. (15 minims) of distilled water 

 and repeat three times at 12-hour intervals; the solution and syringe must, of course, 

 be sterile. 



