192 GARRISON. 



INTRODUCTION, 



The present paper reports the results of a statistical investigation 

 concerning the prevalence of animal parasites among the Filipinos, con- 

 ducted through the year 1907, for the purpose of obtaining accurate 

 knowledge which would serve as a guide to some definite conclusions with 

 regard to the importance of animal parasites and more especially of 

 intestinal worms in the Philippines, and of their possible influence as a 

 factor in determining the hygienic and industrial status of the Filipino 

 people. 



In examining the faeces for these infections, diagnoses were made not 

 only of protozoal and verminous infections of the intestine, but of infec- 

 tions in other organs with worms the ova of which escaped by means of 

 the intestinal tract. Therefore, the investigation was made upon those 

 animal parasites the infection with which could be diagnosed by examina- 

 tion of the fasces and included in addition to parasites of the intestine, 

 certain forms living in the liver (Opisthorcliis, Fasciola, etc.), the lungs 

 (Pamgonimus) , and in the veins or arteries of the lower part of the 

 intestinal tract (Schistosoma). Accordingly, while the expression "in- 

 testinal parasites" would include most of the species considered, the 

 presence of infections with forms not of the intestine, which it was highly 

 desirable to retain in our statistics, made it necessary to employ in the 

 title the broad term of "animal parasites" and to limit its scope as has 

 been indicated. 



A most favorable field for the investigation presented itself at Bilibid 

 Prison where a changing population of about 3,500 prisoners from all 

 parts of the Islands was available for examination and where the routine 

 miscroscopic examination of faeces was already established. 



The great majority of the prisoners were adult male Filipinos, but 

 some native women, a number of Chinese, and a few Americans were 

 among the cases examined. 



Almost all of the population of the prison was examined during the 

 year, the entire work including a total of 4,106 persons. Prisoners 

 newly admitted were subjected to examination at once in quarantine, 

 while the others were placed in a special ward until specimens of fasces 

 could be obtained and studied. In addition, examination was made of the 

 stools of all prisoners admitted to the prison hospital for other causes. 



Specimens were taken from fresh stools obtained after the subject had 

 been given a dose of magnesium sulphate. The necessary number of 

 daily examinations made it impossible to study more than one cover- 

 glass preparation from each specimen and if no infection was detected 



