THE SCHICK REACTION IN FILIPINOS 
By LiBori0 GOMEZ, REGINO NAVARRO, and AMANDO M. KAPAUAN 
Of the Bureau of Science, Manila 
FOUR PLATES 
The Schick reaction consists of the injection of a certain 
amount of diphtheria toxin into the skin of a person in order 
to determine the presence of the corresponding antitoxin. The 
negative reaction indicates the presence of at least 1 /30 to 
1/20 of a unit of a diphtheria antitoxin per cubic centimeter 
of the blood serum, which amount is usually sufficient to protect 
the individual from an attack of diphtheria. The positive re- 
action indicates either a lower content or the total absence of anti- 
toxin in the blood, and the individual is presumably susceptible 
to the disease.(8,4) Therefore, the reaction is a means of 
determining the presence of antitoxic immunity, either natural or 
acquired, and it is now being widely used for the control of 
diphtheria contacts, and also as an index in the immunization 
of persons against the disease. 
In a former paper (2) mention was made of the relative in- 
frequency of diphtheria in the Philippine Islands in spite of 
the presence here of virulent diphtheria bacilli. It has been 
deemed of interest, therefore, to study the Schick reaction among 
Filipinos in order to obtain an idea of their immunity to the 
disease that may help to explain the relatively low incidence 
of the disease among them. 
MATERIAL AND METHOD 
The tests were performed on Filipinos, from infants 6 months 
old to adults of'all ages, and at various times from October, 
1919, to October, 1921. The cases tested were inmates of Gov- 
ernment institutions; the baby nurseries at Singalong and 
Tondo, which gave us the material for infants and young 
children; the Government Orphanage at San Pedro Macati and 
the Boys’ and Girls’ Reformatories, where the inmates were 
children and boys and girls of school age; the San Lazaro 
Hospital Insane Asylum and Bilibid Prison, where the cases 
were adults of both sexes. 323 
