Malaria 617 



clinical attack. In infants and young children with vivax malaria the 

 fever is commonly continuous or remittent, without showing the perio- 

 dicity characteristic of the adult case. The fever stage in quartan malaria 

 is similar to that in tertian but the quartan temperature curves typically 

 show a steeper rise and fall. In malignant tertian a fever of 12-24 hours 

 is not uncommon. The temperature curves usually show fairly broad 

 peaks, sometimes broken by partial remission of the fever. In general, 

 the paroxysms are less clearly defined than in benign tertian and quartan 

 malaria and temperatures may remain above normal for as long as two 

 days or so. 



The sweating stage of the tertian paroxysm sets in after the tempera- 

 ture has started to drop and may last 2-4 hours. The patient usually im- 

 proves rapidly and feels fairly comfortable within a few hours. The 

 sweating stage in quartan malaria is similar, but fails to bring such rapid 

 improvement. A subnormal temperature may persist for a day or two. 

 Sweating is usually less noticeable in malignant tertian, but the stage is 

 accompanied by subnormal temperatures as in the other malarias. 



A tertian periodicity, with paroxysms on alternate days, is characteristic 

 of uncomplicated infections with P. vivax, P. ovale, and P. falciparum. 

 A quartan periodicity, with paroxysms at intervals of about 72 hours, 

 occurs in P. malariae infections. The exact periodicity may vary within 

 a species, however, and average intervals of 43.4, 45.7 and 41.5 hours 

 have been noted for three strains of P. vivax (123). Periodicity is influ- 

 enced also by the occurrence of double or multiple infections. A double 

 infection, for instance, may include strains undergoing merogony on 

 alternate days and producing quotidian paroxysms. In experimental 

 tertian malaria, quotidian paroxysms may occur even after a single in- 

 oculation (10). Such a course may change abruptly into a tertian one, or 

 a new cycle may develop in a tertian course to produce quotidian 

 paroxysms. Similarly, a double quartan course may become quotidian, 

 or a quotidian periodicity may revert to a quartan series. Naturally in- 

 fected patients, in contrast to those with induced malaria, show fewer of 

 these irregularities in quartan and tertian malaria. In malignant tertian, 

 on the other hand, changes and irregularities are common, and tempera- 

 ture curves sometimes suggest the lack of any basic organization. A simple 

 tertian course in falciparutn malaria may even indicate some degree of 

 resistance. The origin of these irregularities is uncertain. The appearance 

 of a new cycle in a tertian or quartan course might be attributed to fresh 

 invasion from an exo-erythrocytic reservoir, but the change from a quo- 

 tidian to a simple tertian or quartan series is another problem. 



Some characteristic effects of the malarias 



Anemia is inevitable in clinical attacks and normal red cell counts 

 are not to be expected except perhaps during the early erythrocytic 



