MALARIA 85 



Daniels says that 600,000,000 red cells could be infected without 

 the victim having " fever." It has been estimated that 300,000,000 

 are required to produce each degree F. rise in the body temperature 

 due to a malarial attack. Anything under this number has been called 

 " latent malaria." 



The different pictures caused by the various malarial parasites will 

 be given in a table later. 



The marked blood destruction during an attack, especially in the 

 subtertian variety, is considerable, but it is made up very quickly 

 during the intermission, so that the number of red cells may be almost 

 normal by the time of the second paroxysm in tertian and quartan 

 cases. Unafifected red cells become pale, vary in shape (poikilocy- 

 tosis), sometimes with megaloblasts (polychromatophilia), basic and 

 granular degeneration with normoblasts. 



OligocythcBmia is always present. If i per cent, of the red cells 

 is attacked and contains a parasite, we should expect a reduction of 

 I per cent, of total red cells. If every twentieth cell, then 5 per cent, 

 of the total destroyed, and so on, but it is not so. Only after one 

 paroxysm of fever the drop may be from 5 per cent, to 10 per cent., 

 and after some one pernicious attack I- to one million per c.c. of blood 

 will be destroyed, and if the pernicious attacks continue the count 

 may be about one million instead of 5|- millions. 



The Hb. value of the remaining corpuscles goes doMm 10 per cent., 

 20 per cent, to 50 per cent, below normal. 



The volume of blood is also diminished as demonstrated post 

 mortem . 



The venous system, apart from that of the portal system, spleen 

 and liver, may be markedly empty. Blood may not flow freely from 

 the pricked finger. The writer's blood during a pernicious attack in 

 Colombia was so viscid and blackish that hcemocvtometer pipettes 

 were repeatedly blocked and no count could be made. 



Anaemia during first attacks is marked, but rapidly replaced. 



Anaemia during the following attack is less marked and less rapidlv 

 replaced . 



The white cells. The leucocytes are at first increased during the 

 rigor, 8,000 to 30,000 in some cases, but thev markedly diminish, 

 causing a leucopsenia with a ratio of i — 500 or 600. In pernicious 

 malaria there may be leucocytosis. Mononuclears are more marked 

 during the leucopasnia, and persist for some time after the fever has 

 subsided. It is a useful factor for diagnosis when the patient is seen 

 after the attack. The increase is relative and absolute; 15 per cent, 

 increase suggests malaria. It is also present in other protozoal 

 infections. 



