PRIMARY ANEMIAS 235 



parasites. The disease in which their increase is best recognized 

 is malaria and an increase to 15% where the blood shows moderate 

 leukopenia is very significant. The melaniferous leukocytes of malaria 

 are cells of this type. 



Other protozoal infections, as kala-azar, trypanosomiasis and amcebiasis cause it. 

 Filterable virus diseases may show a mononuclear increase, thus yellow fever and 

 dengue both give an increase about the fifth or sixth day. 



In Banti's disease there is an increase in cells of this type and a transitional in- 

 crease is reported for Hodgkin's disease. 



DISEASES IN WHICH THERE is A NORMAL LEUKOCYTE COUNT 



Uncomplicated tuberculosis, influenza, Malta fever, measles, try- 

 panosomiasis, malaria, syphilis, and chlorosis. 



In malaria we have a leukocytosis at the time of the rigor, while during the apyrexial 

 period there is a moderate leukopenia. In malaria we have a marked increase in the 

 percentage of the large mononuclears and transitionals. These may form from 25% 

 to 35% of the leukocytes. When bearing particles of pigment they are known as 

 melaniferous leukocytes macrophages which have ingested malarial material. In 

 dengue, at the time of the terminal rash, we may have as great a percentage of large 

 mononuclears. In this disease, however, we have a great diminution of polymor- 

 phonuclears from the start (25 to 40%). Instead of a large mononuclear we have 

 at the onset a lymphocytic increase. There is an increase of large mononuclears in 

 trypanosomiasis. 



The white count is about normal in uncinariasis (Ashford's average 

 was 7800). Some have reported a. leukopenia in severe cases. 



While eosinophilia is the most marked feature in hook-worm disease yet in very 



severe cases it may be absent. 



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THE PRIMARY ANAEMIAS 



Chlorosis. In chlorosis it is the reduction of haemoglobin with the 

 slight numerical variation from normal of the red cells that makes for 

 a diagnosis. The color index is very low. There is nothing abnormal 

 about the leukocytes. Microcytes may be present, and very occasion- 

 ally a normoblast. Macrocytes and megaloblasts are always absent. 

 Blood of chlorotics is very pale and very fluid and coagulates rapidly, 

 hence frequency of thrombosis. 



Spleen, liver, and lymph glands as a rule normal. 



Simple Primary Anaemia. This condition is not recognized by many authors, 

 but is a convenient term under which to group anaemias which are neither chlorosis 



