110 The Philippine Journal of Science 1920 
The object of this paper is to collect and set forth certain sa- 
lient facts concerning carriers in order that they may be avail- 
able for quick reference. 
TYPHOID CARRIERS 
The general belief that typhoid fever is not as common in 
the Tropics as in temperate climates has been found to hold true 
in the Philippines, according to the experience of the Bureau 
of Health. For several years (since 1900) it did not cause 
anxiety to the health officials because only sporadic cases oc- 
curred from time to time. Heiser in 1906—07, in view of Soper’s 
investigations in New York and the occurrence of a prepon- 
derance of the cases among Americans and Japanese in the 
Philippines, announced the probability of the arrival of for- 
eigners with infected gall bladders, or who at least would be 
discharging typhoid bacilli in their stools. During 1908-09 he 
warned against the possibility of the spread of typhoid through 
milk contaminated by infected water or by the hands of bacillus 
carriers, but added that this mode of spread may be disregarded 
since milk is not used on a large scale here. 
During 1910-11 Fox emphasized the fact that it is the walk- 
ing cases and the bacillus carriers that constitute the danger. 
Up to this time, however, laboratory confirmation was lacking. 
In December, 1914, because of the increased prevalence of 
typhoid, a systematic examination of water, milk, and the fzeces 
of persons working in dairies, restaurants, etc., was undertaken. 
As a result, thousands of fecal examinations were made 
but, fortunately, none of them proved positive for the bacillus. 
Similar negative results were obtained with drinking water and 
with milk. 
In 1915 the experience of the previous year was repeated. 
Of the 411 specimens from contacts (covering the entire year) 
none was positive. In the survey for intestinal infection, out 
of 6,201 specimens examined, only 4 were positive for the 
typhoid bacillus. 
In 1916 the board, appointed to investigate the causes of the 
persistence of typhoid in Manila, after a thorough study of the 
subject, arrived at the following conclusions: 
1. That the Centro Escolar outbreak very probably had its 
origin in a carrier (a servant). 
2. That paratyphoid is more prevalent than typhoid in Manila. 
3. That persistence is due to contact infection from either 
