title: Typhoid fever acquired in the United States, 1999-2010: epidemiology, microbiology, and use of a space-time scan statistic for outbreak detection.
abstract: Although rare, typhoid fever cases acquired in the United States continue to be reported. Detection and investigation of outbreaks in these domestically acquired cases offer opportunities to identify chronic carriers. We searched surveillance and laboratory databases for domestically acquired typhoid fever cases, used a space-time scan statistic to identify clusters, and classified clusters as outbreaks or non-outbreaks. From 1999 to 2010, domestically acquired cases accounted for 18% of 3373 reported typhoid fever cases; their isolates were less often multidrug-resistant (2% vs. 15%) compared to isolates from travel-associated cases. We identified 28 outbreaks and two possible outbreaks within 45 space-time clusters of ⩾2 domestically acquired cases, including three outbreaks involving ⩾2 molecular subtypes. The approach detected seven of the ten outbreaks published in the literature or reported to CDC. Although this approach did not definitively identify any previously unrecognized outbreaks, it showed the potential to detect outbreaks of typhoid fever that may escape detection by routine analysis of surveillance data. Sixteen outbreaks had been linked to a carrier. Every case of typhoid fever acquired in a non-endemic country warrants thorough investigation. Space-time scan statistics, together with shoe-leather epidemiology and molecular subtyping, may improve outbreak detection.
authors.affiliation: Division of Foodborne, Waterborne, and Environmental Diseases,Centers for Disease Control and Prevention,Atlanta,GA,USA.
authors.forename: M
authors.initials: M
authors.lastname: Imanishi
authors.affiliation: Division of Foodborne, Waterborne, and Environmental Diseases,Centers for Disease Control and Prevention,Atlanta,GA,USA.
authors.forename: A E
authors.initials: AE
authors.lastname: Newton
authors.affiliation: Division of Foodborne, Waterborne, and Environmental Diseases,Centers for Disease Control and Prevention,Atlanta,GA,USA.
authors.forename: A R
authors.initials: AR
authors.lastname: Vieira
authors.affiliation: Division of Foodborne, Waterborne, and Environmental Diseases,Centers for Disease Control and Prevention,Atlanta,GA,USA.
authors.forename: G
authors.initials: G
authors.lastname: Gonzalez-Aviles
authors.affiliation: Division of Foodborne, Waterborne, and Environmental Diseases,Centers for Disease Control and Prevention,Atlanta,GA,USA.
authors.forename: M E
authors.initials: ME
authors.lastname: Kendall Scott
authors.affiliation: Division of Foodborne, Waterborne, and Environmental Diseases,Centers for Disease Control and Prevention,Atlanta,GA,USA.
authors.forename: K
authors.initials: K
authors.lastname: Manikonda
authors.affiliation: Division of Foodborne, Waterborne, and Environmental Diseases,Centers for Disease Control and Prevention,Atlanta,GA,USA.
authors.forename: T N
authors.initials: TN
authors.lastname: Maxwell
authors.affiliation: Division of Foodborne, Waterborne, and Environmental Diseases,Centers for Disease Control and Prevention,Atlanta,GA,USA.
authors.forename: J L
authors.initials: JL
authors.lastname: Halpin
authors.affiliation: Division of Foodborne, Waterborne, and Environmental Diseases,Centers for Disease Control and Prevention,Atlanta,GA,USA.
authors.forename: M M
authors.initials: MM
authors.lastname: Freeman
authors.affiliation: Division of Foodborne, Waterborne, and Environmental Diseases,Centers for Disease Control and Prevention,Atlanta,GA,USA.
authors.forename: F
authors.initials: F
authors.lastname: Medalla
authors.affiliation: Division of Foodborne, Waterborne, and Environmental Diseases,Centers for Disease Control and Prevention,Atlanta,GA,USA.
authors.forename: T L
authors.initials: TL
authors.lastname: Ayers
authors.affiliation: Division of Foodborne, Waterborne, and Environmental Diseases,Centers for Disease Control and Prevention,Atlanta,GA,USA.
authors.forename: G
authors.initials: G
authors.lastname: Derado
authors.affiliation: Division of Foodborne, Waterborne, and Environmental Diseases,Centers for Disease Control and Prevention,Atlanta,GA,USA.
authors.forename: B E
authors.initials: BE
authors.lastname: Mahon
authors.affiliation: Division of Foodborne, Waterborne, and Environmental Diseases,Centers for Disease Control and Prevention,Atlanta,GA,USA.
authors.forename: E D
authors.initials: ED
authors.lastname: Mintz
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D002648:Child; D002675:Child, Preschool; D004196:Disease Outbreaks; D024901:Drug Resistance, Multiple, Bacterial / Q000502:physiology; D062665:Epidemiological Monitoring; D005260:Female; D006801:Humans; D007223:Infant; D007231:Infant, Newborn; D008297:Male; D008875:Middle Aged; D012485:Salmonella typhi / Q000302:isolation & purification* / Q000502:physiology; D013029:Space-Time Clustering; D014195:Travel; D014435:Typhoid Fever / Q000453:epidemiology* / Q000382:microbiology; D014481:United States / Q000453:epidemiology; D055815:Young Adult
keywords: Epidemiology; outbreaks; surveillance system; typhoid fever (Salmonella Typhi)