MEDICAL SURVEY OF THE TOWN OF TAYTAY. 



XII. EXAJIINATIOXS OF THE BLOOD WITH SPECIAL REFERENCE TO MALARIA. 



By Luis Guerrero and Victor Sevilla. 



Malaria is endemic in the Philippines and is present throughout the 

 whole year, though the number of cases varies at different seasons. Dur- 

 ing the months of March to June, the amount is small, later in the year 

 it begins to increase in a remarkable manner, and in the months of 

 ]SJ"ovember, December, January, and Fel)ruarv — that is, after the rainy 

 season is over — it becomes much more prevalent. During this last period 

 a large number of cases occur in the infected districts, especially among 

 tlie country people, and there have been occasions wlien the harvesting 

 of rice had to be suspended on account of the number of people afflicted 

 with this disease. Ag the epidemics frequently coincide with the rice 

 harvest, the natives usually ascribe the cause of the disease to the ingestion 

 of green rice, that is, to rice newly mown. 



According to the investigations of Craig ^ at Camp Stotsenberg. the 

 recrudescence of malaria coincides witli the abundance of AnopheTes, and 

 undoubtedly such must be also the case witli the other infected areas of 

 the Archipelago, for at the end of the rainy season, when the fields become 

 dry, pools and otlier natural receptacles for water are left, M'hich are used 

 f(u- breeding places by mosquitoes. 



TJie investigations at Taytay upon malaria were conducted during the 

 uionths of March. April and May, in the midst of the hot season, when 

 the fields were entirely dry and many of the sources of water supply 

 almost exhausted. Only after jirolongcd search was a breeding place of 

 Anoplich'M found: this was in the neighborhood of a well fi'om which part 

 of the inhabitants obtained their water su])ply. Among the l.lHl per- 

 sons wlio visited the dis])ensary, only 16 cases M'ere found to he infected 

 with, malaria. This number agrees very well with the scarcity of Ann- 

 jilu'/cs. .\s to the type of the jiarasite. 1"^ were iul'ected with the tertian 



'Thin Jounml (1006). 1, 523. 



273 



