title: Twenty-six years of enteric fever in Australia: an epidemiological analysis of antibiotic resistance.
abstract: OBJECTIVE
  To determine incidence and trends in antibiotic resistance in Australian Salmonella enterica subspecies enterica serovars Typhi (S. Typhi) and Paratyphi (S. Paratyphi) isolates over the past 26 years.
  
  
  METHODS
  A retrospective analysis of consecutive microbiologically confirmed enteric fever isolates.
  
  
  METHODS
  All S. Typhi and S. Paratyphi isolates from patients diagnosed with enteric fever in Australia between 1985 and 2010.
  
  
  METHODS
  Incidence and variation in antibiotic resistance over time and according to country of origin.
  
  
  RESULTS
  We analysed 2551 isolates, which originated from 74 countries or regions, mainly India (33%) and Indonesia (22%). The incidence among Australian residents increased from four to five before 2003 to seven cases per million person-years after 2003. Multidrug resistance (chloramphenicol, ampicillin, trimethoprim) and nalidixic acid resistance emerged rapidly from the early 1990s, with nalidixic acid resistance increasing to 70% in 2009-2010, while multidrug resistance was relatively stable at between 4% and 11%. Nalidixic acid and multidrug resistance rates are highest in isolates from the Indian subcontinent. Some countries in South-East Asia, such as Indonesia, had very low rates of resistance; however, this varied across the region.
  
  
  CONCLUSIONS
  Nalidixic acid resistance has become widespread in enteric fever isolates from the Indian subcontinent and some parts of South-East Asia, justifying the use of ceftriaxone or azithromycin rather than ciprofloxacin as first-line treatment. However, resistance in some countries remains rare, potentially allowing treatment to be adjusted according to country of origin.
authors.affiliation: Victorian Infectious Diseases Service, Royal Melbourne Hospital, Melbourne, VIC, Australia. robert.commons@gmail.com
authors.forename: Robert J
authors.initials: RJ
authors.lastname: Commons
authors.forename: Emma
authors.initials: E
authors.lastname: McBryde
authors.forename: Mary
authors.initials: M
authors.lastname: Valcanis
authors.forename: Joan
authors.initials: J
authors.lastname: Powling
authors.forename: Alan
authors.initials: A
authors.lastname: Street
authors.forename: Geoff
authors.initials: G
authors.lastname: Hogg
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D000900:Anti-Bacterial Agents / Q000494:pharmacology*; D001210:Asia, Southeastern; D001315:Australia / Q000453:epidemiology; D002648:Child; D002675:Child, Preschool; D024881:Drug Resistance, Bacterial; D024901:Drug Resistance, Multiple, Bacterial; D005260:Female; D006801:Humans; D015994:Incidence; D007223:Infant; D007231:Infant, Newborn; D016015:Logistic Models; D008297:Male; D008826:Microbial Sensitivity Tests; D008875:Middle Aged; D009268:Nalidixic Acid / Q000494:pharmacology; D012189:Retrospective Studies; D012485:Salmonella typhi / Q000187:drug effects* / Q000302:isolation & purification; D014435:Typhoid Fever / Q000453:epidemiology / Q000382:microbiology*; D055815:Young Adult
chemical_list: D000900:Anti-Bacterial Agents; D009268:Nalidixic Acid