IS, 4 
Haughwout: Human Coccidiosis 
473 
It was in the Bual district, however, where the excreta dis- 
posal conditions were the worst. In this section of country, 
where there are any closet facilities whatever, the system is 
what is colloquially spoken of as the “pig system.” The “pig 
system” is widely employed throughout the Tropics as a labor- 
saving institution under the mistaken notion that the pig altruis- 
tically protects mankind against the spread of intestinal diseases. 
Incidentally, his activities are supposed to result in economy of 
municipal funds. I have accumulated sufficient evidence dur- 
ing my stay in the Philippine Islands to convince myself that 
in his role as a sanitarian and public benefactor the domestic 
pig is a dismal failure, and that, while he brings about a super- 
ficial appearance of cleanliness, he really makes a bad matter 
worse by distributing a more or less localized filth broadcast 
within a settlement. The back doors of latrines are left open for 
his convenience, he avails himself of the facilities thus afforded 
him, and then sallies forth upon the highway and among the 
children of the village, in their mud-pie industry, fulfilling his 
errand of dissemination. In the course of time he has distri- 
buted his corisignment of human parasites, shipped at the latrine, 
and may even have added a few of his own in the form of 
Balantidium coli. 
From such observations as I have been able to make, I believe 
that the ova and cysts of the general run of intestinal parasites 
of man pass unchanged through the alimentary tract of the pig 
and emerge quite as potential for harm as if they never had 
made the journey. Therefore, it seems to me not at all unlikely 
that in this country, where the parasitic index already is high, 
we may expect, in the course of time, to encounter new cases of 
infection with Isospora. 
There are several means by which the cysts of Isospora in an 
infective stage may be transmitted in a country such as this. 
Direct transmission through the medium of the soiled hands 
of a food handler is not altogether impossible for I have shown 
(p. 462) that, under certain conditions, cysts may reach full 
development within thirty-two hours after the passage of the stool 
containing them. I have known food handlers who refrained 
from washing their hands over even longer periods than this. 
Flies, pigs, and probably cockroaches must be accepted as 
likely vectors, and there is the old bogey of green vegetables 
fertilized with human excreta. In fact, the methods of trans- 
mission are much the same as in the case of the other intestinal 
Protozoa. Peculiar factors involved are the longevity and 
