title: Low and declining attack rates of imported typhoid fever in the Netherlands 1997-2014, in spite of a restricted vaccination policy.
abstract: Typhoid fever mainly occurs in (sub) tropical regions where sanitary conditions remain poor. In other regions it occurs mainly among returning travelers or their direct contacts. The aim of this study was to evaluate the current Dutch guidelines for typhoid vaccination.
  
  
  
  Crude annual attack rates (AR) per 100,000 Dutch travelers were calculated during the period 1997 to 2014 by dividing the number of typhoid fever cases by the estimated total number of travelers to a specific country or region. Regions of exposure and possible risk factors were evaluated.
  
  
  
  During the study period 607 cases of typhoid fever were reported. Most cases were imported from Asia (60%). Almost half of the cases were ethnically related to typhoid risk regions and 37% were cases visiting friends and relatives. The overall ARs for travelers to all regions declined significantly. Countries with the highest ARs were India (29 per 100,000), Indonesia (8 per 100,000), and Morocco (10 per 100,000). There was a significant decline in ARs among travelers to popular travel destinations such as Morocco, Turkey, and Indonesia. ARs among travelers to intermediate-risk areas according to the Dutch guidelines such as Latin America or Sub-Saharan Africa remained very low, despite the restricted vaccination policy for these areas compared to many other guidelines.
  
  
  
  The overall AR of typhoid fever among travelers returning to the Netherlands is very low and has declined in the past 20 years. The Dutch vaccination policy not to vaccinate short-term travelers to Latin-America, Sub-Saharan Africa, Thailand and Malaysia seems to be justified, because the ARs for these destinations remain very low. These results suggest that further restriction of the Dutch vaccination policy is justified.
authors.affiliation: Department of Infectious Diseases, Public Health Service (GGD) of Amsterdam, Nieuwe Achtergracht 100, PO Box 2200, 1000 CE, Amsterdam, The Netherlands. fsuryapranata@ggd.amsterdam.nl.|National Coordination Centre for Travellers' Health Advice (LCR), Nieuwe Achtergracht 100, PO Box 1008, 1000 BA, Amsterdam, The Netherlands. fsuryapranata@ggd.amsterdam.nl.
authors.forename: F S T
authors.initials: FS
authors.lastname: Suryapranata
authors.affiliation: Department of Infectious Diseases, Public Health Service (GGD) of Amsterdam, Nieuwe Achtergracht 100, PO Box 2200, 1000 CE, Amsterdam, The Netherlands.|Department of Internal Medicine, Division of Infectious Diseases, Tropical Medicine and AIDS, Academic Medical Centre, Meibergdreef 9, 1105 AZ, Amsterdam, The Netherlands.
authors.forename: M
authors.initials: M
authors.lastname: Prins
authors.affiliation: Department of Infectious Diseases, Public Health Service (GGD) of Amsterdam, Nieuwe Achtergracht 100, PO Box 2200, 1000 CE, Amsterdam, The Netherlands.|National Coordination Centre for Travellers' Health Advice (LCR), Nieuwe Achtergracht 100, PO Box 1008, 1000 BA, Amsterdam, The Netherlands.|Department of Internal Medicine, Division of Infectious Diseases, Tropical Medicine and AIDS, Academic Medical Centre, Meibergdreef 9, 1105 AZ, Amsterdam, The Netherlands.
authors.forename: G J B
authors.initials: GJ
authors.lastname: Sonder
mesh_terms: D000293:Adolescent; D000328:Adult; D017954:Africa South of the Sahara; D005260:Female; D006291:Health Policy; D006801:Humans; D015994:Incidence; D008297:Male; D009426:Netherlands / Q000453:epidemiology; D011322:Primary Prevention / Q000706:statistics & numerical data; D012307:Risk Factors; D014195:Travel / Q000706:statistics & numerical data*; D014330:Tropical Medicine; D014435:Typhoid Fever / Q000453:epidemiology* / Q000517:prevention & control; D014436:Typhoid-Paratyphoid Vaccines / Q000008:administration & dosage*; D014611:Vaccination / Q000592:standards*; D055815:Young Adult
chemical_list: D014436:Typhoid-Paratyphoid Vaccines
keywords: Epidemiology; Guidelines; Travel; Typhoid fever; Vaccination