7 After reviewing comparable published estimates on global typhoid incidence, the authors developed incidence brackets for each destination, dividing them into three categories: low if <10/100,000 cases/year; medium if 10–100/100,000 cases/year; and high see more if >100/100,000 cases/year. Because country-level incidence data do not always adequately represent a traveler’s risk for acquiring typhoid fever, incidence classifications were compared to CDC’s national surveillance
database of travel- and domestically acquired typhoid fever cases in the United States.8 All travel-related cases reported to CDC during 1999–2008 were matched to their reported countries of exposure to determine where travelers are most often exposed to typhoid fever. A total of 2,077 records were reviewed. Countries were ranked by the cumulative number of imported cases during this timeframe as a proportion of all cases reported to CDC. This step was included PD0332991 price to identify any “hotspots” for typhoid exposure among US travelers that may not be reflected in endemic incidence rates. It was not possible to calculate incidence rates because we could not accurately determine the number of US travelers exposed. Therefore, we did not set numeric cut-offs for
low, medium, filipin and high rates of imported cases. On a case-by-case basis, the review team compared the endemic incidence rate to the proportion of imported cases among US travelers to assign a destination-specific risk category for each country. These destination-specific risk categories were then used to inform destination-specific recommendations for pre-travel typhoid vaccination. Based on consensus among CDC experts in THB and enteric diseases, it was decided that vaccination would be recommended
for destinations falling into the medium- and high-risk categories, while the low-risk category would result in a recommendation not to vaccinate. As a result of this review, the typhoid vaccine recommendation remained unchanged for 212 (89%) of the 238 destinations. Changes did occur in the Eastern European and Middle Eastern regions, where 26 countries for which typhoid vaccine was previously recommended based on presumed risk, were downgraded to the low-risk category (Figure 1). These destinations are Albania, Armenia, Azerbaijan, Belarus, Bosnia and Herzegovina, Bulgaria, Croatia, Cyprus, Czech Republic, Estonia, Georgia, Hungary, Israel, Kosovo, Latvia, Lithuania, Macedonia, Moldova, Montenegro, Poland, Romania, Russia, Serbia, Slovakia, Slovenia, and Ukraine.