PLASMODIUM, HAEMOPROTEUS AND LEUCOCYTOZOON 



265 



occurred at a Campfire Girl camp at 

 Lake Vera, California. A marine visited 

 the camp on July 4, 1952, and spent the' 

 night. He had a malarial relapse while he 

 was there, and was sleeping without a 

 mosquito bar. Within a few weeks the 

 first case appeared among the girls, and 

 cases continued to appear until January or 

 February. A total of 35 cases of vivax 

 malaria occurred among that group of 

 girls as the result of one night's exposure 

 from one infected marine. 



There are no obvious technical or 

 economic reasons why malaria could not 

 be eradicated from the Americas, Europe, 

 Australia and much of Asia during the 

 next quarter century, altho the situation is 

 not so promising in tropical Africa (Wil- 

 liams, 1958). This can be done almost 

 entirely by residual spraying of dwellings. 

 The cost of protection has been found to 

 vary from 11 to 45 cents per capita per 

 year. Properly conducted, residual house 

 spraying for 2 to 3 years will eradicate 

 Plasmodium , altho the mosquito vector 

 may persist. Some mosquitoes have de- 

 veloped a resistance to DDT, but this has 

 always taken at least 6 years, so malaria 

 can be eliminated before the mosquitoes 

 become resistant. 



New problems result from disease 

 control, however. These are well illus- 

 trated by the effect of malaria control on 

 the population of Ceylon. The birth rate 

 on that island was 40 per 1000 in 1920, 

 and it was still about the same in 1950. 

 But the death rate in 1920 was 32 per 

 1000, while in 1950 it was 12 per 1000, 

 and this decrease was due primarily to 

 the elimination of malaria. This means 

 that if both the present birth and death 

 rates are maintained, the population of 

 Ceylon will double in about 26 years. And 

 how can all these additional millions be 

 fed? (Stone, 1954). 



Diagnosis : Malaria can be diagnosed 

 with certainty only by finding and identify- 

 ing the causative organisms in the blood. 

 This is done by microscopic examination 

 of smears stained with one of the Roman- 

 owsky stains; Giemsa's stain is best. At 

 one time thin smears were used almost 



entirely, but thick, laked smears are much 

 better, since they permit a much larger 

 amount of blood to be examined in a given 

 time. Identification of the species and 

 stages requires skill and practice. An ex- 

 cellent guide with outstanding colored illus- 

 trations is that of Wilcox (1960). 



Treatment : A number of drugs have 

 been used in treating malaria. The first 

 one was quinine, the most active ingredi- 

 ent of cinchona bark, which was identified 

 in 1820 by Pelletier and Caventou. It is 

 both suppressive and curative, but does 

 not prevent relapses. Chemically it is 

 6-methoxy-alpha-(5-vinyl-2-quinuclidyl-4- 

 quinoline-methanol). 



Quinacrine (Atebrin, Atabrine, mepa- 

 crine) was discovered by Mauss and 

 Mietsch (1933) in Germany. It is 2-chloro- 

 5-diethylamino-isopentylamino-7-methoxy- 

 acridine dihydrochloride. It was used ex- 

 tensively during World War II when the 

 Indonesian cinchona plantations were taken 

 over by the Japanese. It is actually better 

 than quinine. It is prophylactic against 

 falciparum malaria and suppressive 

 against vivax and malariae malarias. It 

 cures attacks of the disease, but does not 

 prevent relapses. One disadvantage is 

 that it is a dye and stains the skin yellow. 



Chloroquine (Aralen) is 7-chloro-4, 

 4-dimethylamino-l-methylbutylaminoquin- 

 oline. It was developed thru a crash drug- 

 testing program during World War II in 

 which the Americans tested over 14,000 

 compounds and the British about half as 

 many. The results of the American effort 

 are summarized by Wiselogle (1946). 

 Chloroquine appeared too late to be used 

 in that war except experimentally. It is 

 the most effective drug known for the treat- 

 ment and suppression of all types of ma- 

 laria. The recommended therapeutic dose 

 is 1. 5 g in 3 days. Following its use, fever 

 subsides in a day, and the parasites dis- 

 appear from the blood in 2 or 3 days. The 

 suppressive dose is 0. 3 g weekly. Chlor- 

 oquine does not prevent vivax malaria re- 

 lapses, however. 



Primaquine appeared even later than 

 chloroquine, having been introduced in 



