Laboratory-Based Surveillance of Salmonella Serotype Typhi Infections in the United States

Abstract
Since the mid-1960s, the incidence of infections due to Salmonella serotype Typhi in the United States has been stable at about 0.2 cases per 100,000 persons per year. While the incidence has stabilized, the estimated proportion of cases diagnosed in the United States and acquired abroad increased from 33% in 1967-19721 to 62% in 1975-19842 and to 72% in 1985-1994.3