THE INCIDENCE OF ENCAPSULATED STAPHYLOCOCCI AND ANTICAPSULAR ANTIBODIES IN NORMAL HUMANS

Abstract

A group of 109 healthy adult blood donors was examined to determine the incidence of anticapsular antibodies capable of eliciting a specific capsular reaction when tested against an encapsulated strain of Staphylococcus aureus. At the same time the carrier rate for naturally occurring encapsulated S. aureus variants was determined. Of the healthy blood donors 80.7% possessed anticapsular antibodies in sufficient titer to elicit a specific capsular reaction. Almost half the carriers of staphylococci carried naturally occurring encapsulated strains of S. aureus. In a group of subjects below the age of 13 years, a lower incidence of anticapsular antibodies was found.