82 



WILLETS. 



and at 8an Antonio 8.94 per cent of those examined harbored the 

 whipworm. At the latter place the percentage was raised because of 

 the presence of some Visayans who had been in the valley about one 

 year and many of whom were infected with the parasite in question and 

 because the inhabitants of certain cabecerias made frequent visits in 

 Ilagan Central. 



The low percentage of whipworm infection probably is due to a lack 

 of introduction of this parasite in great nmnbers in the haciendas. 

 Trichuris and Ascaris have thick-shelled ova and high percentages of 

 these parasites are not infrequently found in a given community. The 

 conditions favorable for the propagation of the one are, in a general way, 

 favorable for the other. Now, the round worm is the parasite which 

 occurs most frequently at the two haciendas. That the lack of intro- 

 duction in sufficiently great numbers accounts for the relative infre- 

 quency of the whipworm is supported further by the fact that the neigh- 

 bors of the Visayans to whom reference has been made and persons living 

 near Ilagan Central show a higher percentage of infection with this 

 parasite than do those who live at a distance. 



Trematode ova in the stool of a boy 13 years of age appeared to be 

 those of Fascioletfa ilocana Garrison. Other than this, no unusual in- 

 fection was seen. 



COMPARISON OF FINDINGS AT SAN ANTONIO AND MALUNO. 



Practically all of the people at the haciendas are of the same origin, 

 and since the}' are all engaged in the same sort of labor in the same kind 

 of soil it was to be expected that there would be but slight variations 

 in the findings at the two places. This proved to be true. 



Table IV shows the percentage of persons at the two haciendas who 

 harbored single, double, triple, and quadruple infections and also the 

 number per 100 persons examined. The great majority of the single 

 infections was with the hookworm, or Ascans; of the double, hookwonn 

 and Ascaris; and of the triple, hookworm, Ascaris and Trichuris. 



Table IV. — Percentage of persons harboring intestinal parasites at San Antonio 



and Maltino. 



Place. 



No. 

 ex- 

 am- 

 ined. 







Infections. 







Infected. 



Single. 



Double. 



Triple. 



Quadru- 

 ple. 



infection.'- 



Nnm- 

 ber. 



Per 



cent. 



Num- 

 ber. 



Per 

 cent. 



Num- 

 ber. 



Per 

 cent. 



Num- 

 ber. 



Per 

 cent. 



Num- 

 ber. 



Per 

 cent. 



Num- 

 ber. 



Per 

 cent. 



San Antonio.-- 

 Maluno 



Total 



3,310 

 968 



2,819 

 837 



85.16 

 86.47 



1,529 

 509 



46.19 

 52. 58 



1,133 

 311 



34.23 

 32.13 



151 

 17 



4.56 

 1.76 



6 

 



0.18 

 0.00 



4,272 

 1,182 



129.06 

 122.111 



4,278 |3,656 



85.46 



2, 038 



47.64 



1,444 



33.75 



168 



3.93 



6 



0.14 



5, 454 



127.49 



