title: Typhoid fever cases in the U.S. military.
abstract: BACKGROUND
  Salmonella enterica, serovar Typhi (S. Typhi), a causative agent of enteric fever (typhoid fever), predominately affects populations in developing regions with poor access to clean food and water. In addition, travelers to these regions are at risk of exposure.
  
  
  METHODS
  We report the epidemiological characteristics of S. Typhi cases among active duty United States military personnel from 1998 to 2011 using data obtained from the Defense Medical Surveillance System. Cases were identified based on International Classification for Disease Ninth Edition - Clinical Modification codes.
  
  
  RESULTS
  We identified a total of 205 cases S. Typhi for an incidence of 1.09 per 100,000 person-years. Cases were on average 31.7 years old, predominately married (n = 129, 62.9 %), Caucasian (n = 142, 69.3 %), male (n = 176, 85.9 %), and had a high school education (n = 101, 49.3 %). Of the identified cases, 122 had received a Typhoid vaccination within 4 years of diagnosis.
  
  
  CONCLUSIONS
  This study provides an overview of enteric fever in the United States military. The incidence was similar to the general U.S. population except for increased incidence from 1998 to 2000, perhaps attributable to operational deployments in that period. Given that vaccination is an effective primary prevention measure against typhoid fever, active monitoring of pre-deployment vaccine history is warranted.
authors.affiliation: Enteric Diseases Department, Infectious Disease Directorate, Naval Medical Research Center, 503 Robert Grant Avenue, Silver Spring, MD, 20910, USA. tia.sorrell@gmail.com.
authors.forename: Tia
authors.initials: T
authors.lastname: Sorrell
authors.affiliation: Enteric Diseases Department, Infectious Disease Directorate, Naval Medical Research Center, 503 Robert Grant Avenue, Silver Spring, MD, 20910, USA. Daniel.j.selig@gmail.com.
authors.forename: Daniel J
authors.initials: DJ
authors.lastname: Selig
authors.affiliation: Enteric Diseases Department, Infectious Disease Directorate, Naval Medical Research Center, 503 Robert Grant Avenue, Silver Spring, MD, 20910, USA. mark.s.riddle10.mil@mail.mil.
authors.forename: Mark S
authors.initials: MS
authors.lastname: Riddle
authors.affiliation: Enteric Diseases Department, Infectious Disease Directorate, Naval Medical Research Center, 503 Robert Grant Avenue, Silver Spring, MD, 20910, USA. chad.k.porter2.civ@mail.mil.
authors.forename: Chad K
authors.initials: CK
authors.lastname: Porter
mesh_terms: D000328:Adult; D005260:Female; D006801:Humans; D015994:Incidence; D008297:Male; D008889:Military Personnel / Q000706:statistics & numerical data*; D012189:Retrospective Studies; D012485:Salmonella typhi / Q000302:isolation & purification; D014435:Typhoid Fever / Q000453:epidemiology* / Q000382:microbiology / Q000517:prevention & control; D014436:Typhoid-Paratyphoid Vaccines / Q000627:therapeutic use; D014481:United States / Q000453:epidemiology; D014611:Vaccination; D055815:Young Adult
chemical_list: D014436:Typhoid-Paratyphoid Vaccines