266 



PLASMODIUM, RAEMOPROTEUS AND LEUCOCYTOZOON 



1949. It is 8-(4-amino-l-methylbutyl- 

 amino)-6-methoxyquinoline. It is most 

 useful as a truly curative agent against 

 vivax malaria, since it not only cures 

 attacks but prevents relapses. It is best 

 used in combination with chloroquine if 

 the patient is having an attack, but can be 

 used alone in between relapses to prevent 

 further relapses. The dosage is 15 mg 

 daily for 14 days. The effectiveness of 

 this drug in preventing relapses was 

 proven in returning Korean veterans. 



Chlorguanide (Paludrine, Proguanil) 

 was developed by the British during 

 World War H. It is N-p-chlorophenyl-N- 

 5-isopropylbiguanide. It showed a great 

 deal of promise, but after it had been 

 used for a while, resistant strains of 

 Plasmodium appeared, and it is no longer 

 being used. 



Pyrimethamine (Daraprim, Malocide) 

 was introduced by the British in 1951. Its 

 discovery grew out of the World War 11 

 study. It is 2,4-diamino-5-p-chlorophenyl- 

 6-ethylpyrimidine. It is perhaps the best 

 suppressive drug known, altho it is not 

 recommended for the treatment of malarial 

 attacks. In single weekly doses of 25 mg 

 it completely suppresses all Plasmodium 

 species and is prophylactic against P. 

 falciparum and some strains of P. vivax. 

 In addition, it destroys P. falciparum 

 gametocytes, so that it has value in the 

 epidemiological control of this type of 

 malaria. It is being mixed with the salt 

 for prophylaxis in some parts of the 

 Americas. Unfortunately, resistant 

 strains have appeared in some areas 

 where it has been used, and its eventual 

 value is uncertain. 



Many other drugs have been used for 

 treating malaria, but these are the most 

 important. At present, the ones gener- 

 ally recommended are chloroquine, prima- 

 quine and pyrimethamine. 



BIRD MAiARIA 



A tremendous amount of work has 

 been done on the bird malarias. The 

 avian species of Plasmodium lend them- 



selves well to experimentation, and, until 

 the discovery of P. bergliei in rodents in 

 1948, birds were the only experimental 

 animals in which malaria could be conven- 

 iently studied. All the drug screening for 

 antimalarials in World War II was carried 

 out in birds (Wiselogle, 1946). 



About 40 species of Plas»wdii(i)i have 

 been described from birds, but only 14 or 

 15 are accepted as valid (Hewitt, 1940; 

 Bray, 1957; Laird and Lari, 1958). Many 

 wild birds are commonly infected. The 

 most complete general review of bird 

 malaria is that of Hewitt (1940), altho it is 

 now somewhat out of date. Herman (1944) 

 and Coatney and Roudabush (1949) have 

 given catalogs and host-indices of the spe- 

 cies of Plasmodium in birds. Levine and 

 Hanson (1953) tabulated reports of Plas- 

 modium from waterfowl, and Levine and 

 Kantor (1959) did the same for birds of 

 the order Columbiformes. Other more 

 recent general papers are those of Becker 

 (1959), Bray (1957), Herman et al. (1954), 

 Huff (1954) and Wolfson (1941). 



Bird malaria is not of great veterinary 

 importance, but it may occasionally cause 

 losses, especially in pigeons. Most of the 

 species are not strongly host specific and 

 can infect several species of birds. Most 

 laboratory studies have been carried out 

 with Plasmodium cathemerium and P. 

 relictum in the canary, P. gallinaceum in 

 the chicken and P. lophurae in the duck. 



The avian species of Plasmodium fall 

 into 2 groups, depending upon whether 

 their gametocytes are round or elongate. 

 Among those with round gametocytes are 

 P. cathei)ieriu»i, P. relictum and P- gal- 

 linaceum. Among those with elongate 

 gametocytes are P. circumflexum , P. 

 micleophilum , P. rouxi, P. elongatum, 

 P. hexamerium, P. vaughani and P. 

 polare. P. lophurae is somewhat different; 

 its gametocytes are elongate at first but 

 continue to grow and come to fill up the 

 whole host cell except for the nucleus. 



Cutting across these morphological 

 groups are the two groups based on the 

 type of cell invaded by the exoerythrocytic 

 forms mentioned on page 261. 



