DISCOVERY OF TYPHOID CARRIER BY SEWAGE SAMPLING

Abstract

A method was applied for the bacteriological sampling of sewage through manholes at crucial points in an urban sewerage system in order to locate carriers of typhoid. The map shown here gives the arrangement of sewers in a city of 2,200 population where four cases had occurred in five years. The sampling method narrowed the field of inquiry to a small area, and bacteriophage typing of the Salmonella obtained yielded the final clue that led to identification of the carrier. The most significant advantage of this method is the ability to locate a carrier by use of a practical field study technique when the usual epidemiologic methods have failed.