540 Host-Parasite Relationships 



are widely distributed and their incidence seems to vary considerably in 

 different areas. 



Central and southern Africa 



Except for such climatically unfavorable areas as the Sahara, 

 malaria extends throughout most of the continent into the Union of 

 South Africa. The incidence is high in many regions and a native with no 

 malarial experience is a rarity in the Belgian Congo and various other 

 parts of tropical Africa. The distribution of the major types of malaria 

 varies with the region. Benign tertian is apparently less common than 

 malignant tertian in the Belgian Congo, Nigeria, the Gold Coast, and 

 Togo, for example, but may represent 20-30 per cent of the cases in the 

 Union of South Africa. Quartan malaria is fairly common in Togo, less 

 common than benign tertian in Nigeria, rare in Kenya Colony and the 

 Cameroons, and rare or absent in Bechuanaland. Trypanosomiasis (Afri- 

 can sleeping sickness) extends from Gambia and French West Africa east- 

 ward to Kenya and as far south as Southern Rhodesia. Kala-azar has 

 occurred sporadically along the border of the Sudan and Ethiopa but 

 apparently has not extended westward or southward. Available data 

 indicate that amoebiasis and other intestinal infections are very common 

 in many parts of tropical Africa and apparently less common in others. 

 Madagascar, off the southeastern coast of Africa, is a center of endemic 

 and widely distributed malaria, malignant tertian being important. 

 Amoebiasis is at least as common in Madagascar as in most parts of the 

 mainland. 



Southern and southeastern Asia 



Malaria extends from the shores of the Red and Caspian seas 

 across Asia to southern and eastern China, and farther inland, from 

 the Caspian Sea well into southern Russia. For most of this area, the 

 real incidence of malaria is unknown. Incomplete data suggest that an 

 estimate of 2,000,000 cases a year, about a third of them malignant 

 tertian, would be fairly conservative for India. Malaria also is important 

 in Thailand, which has experienced a malarial death rate of 3 to 4 per 

 thousand more than once within the past thirty years. Kala-azar extends 

 from Turkey and Iraq eastward into India, Burma, Thailand, Indo- 

 China, and China. The disease is considered an important health problem 

 in India and China but is apparently rare in Thailand and Indo-China. 

 Oriental sore extends from Turkey, Arabia, and Iran into India. Amoe- 

 biasis is probably common throughout the area. 



The Pacific area 



In Australia, malaria is endemic along the northern coast but 

 not elsewhere. Amoebiasis is probably general in distribution, along 



