From the CDC: New Country‐Specific Recommendations for Pre‐Travel Typhoid Vaccination

Katherine J. Johnson MPH, Nancy M. Gallagher BA, Eric D. Mintz MD, Anna E. Newton MPH, Gary W. Brunette MD, Phyllis E. Kozarsky MD
DOI: 430-433 First published online: 1 November 2011


Typhoid fever continues to be an important concern for travelers visiting many parts of the world. This communication provides updated guidance for pre‐travel typhoid vaccination from the US Centers for Disease Control and Prevention (CDC) and describes the methodology for assigning country‐specific recommendations.

Typhoid fever is a serious illness and a disease of public health significance that continues to impact travelers.1,2 While the risk to travelers in high‐transmission areas, such as the Indian subcontinent, is well established, epidemiologic data at the subregional or country level are limited for many areas.3–5 The lack of information on disease risk makes the decision of whether to recommend typhoid vaccination for travelers to these areas, a challenging one for health care providers.

The CDC Travelers' Health Branch (THB) provides country‐specific recommendations about travel‐related diseases through its website (, which receives over 27 million unique page views per year and is THB's most comprehensive communication tool.6 Historically, recommendations were provided on a regional basis only. In 2007, CDC transitioned to country‐specific recommendations, but limitations in subregional data often resulted in regional recommendations being applied to all countries within each region.

To reflect important epidemiologic differences that may impact travel‐related disease risks, we systematically reviewed all country‐specific recommendations. In 2010, THB met with CDC experts in enteric diseases to begin this process for all country‐specific typhoid recommendations for travelers. This team was formed to review and update these recommendations through an iterative consensus process over a period of months.

Sources and Methods

We examined a total of 238 destinations worldwide (including countries, special administrative areas, non‐self‐governing territories, island groupings, and other overseas territories), divided into 19 regions, that are featured on the Travelers' Health website. For all regions, destination‐specific data were collected from a variety of sources, including published literature on the incidence of typhoid and paratyphoid fever by country or region; US national surveillance for travel‐related cases; country‐level incidence data published on the websites of WHO regional offices, Ministries of Health, or their equivalent; and the Global Foodborne Infections Network country databank, a WHO‐sponsored voluntary reporting system.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 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 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, 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.

Results and Discussion

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.

Figure 1

CDC revised recommendations for pre‐travel typhoid vaccination.

In the United States during 1999–2008, an average of 53 domestically acquired typhoid cases, or 0.02/100,000 cases/year, were reported annually to CDC. For the destinations in Figure 1, the country‐specific incidence rates ranged from 0 to 0.91/100,000 reported cases/year with a median of 0.01/100,000 cases/year, well below the low incidence ceiling of 10/100,000 cases/year. Furthermore, only five cases (0.2%) of typhoid imported into the United States during 1999–2008 were potentially linked to these destinations. Two of these ill travelers reported visiting a single country of exposure, Hungary and Russia, respectively. The remaining three ill travelers reported visiting multiple countries worldwide, making the actual country of exposure difficult to determine: the first of these three travelers reported visiting Austria, Germany, Hungary, and the Czech Republic; the second visited India, the Czech Republic, the UK, and Slovakia; the third visited Afghanistan, India, and Russia.

While the risk behaviors of travelers and resident populations are not directly comparable, these data suggest that the overall risk of acquiring typhoid during travel to these destinations is low. Factors such as improved sanitation and water supply probably contributed to these results, especially in countries like Belarus, the Czech Republic, Estonia, and Poland, which have reported increased access to improved water sources in both urban and rural areas.9,10


This review highlights some of the challenges faced by public health agencies charged with providing destination‐specific travel recommendations for travelers. Our assessment focused on US travelers and may not be widely applicable to travelers from other parts of the world whose risk behaviors may vary. We also chose to rely on internal CDC subject‐matter expertise, comprising several groups across the agency, instead of employing the Delphi method and engaging external global experts in a more formal review process. For these reasons, we limited our results section to the destinations with enough data to support a change in recommendation. With limited data for some parts of the world, input from global partners would be valuable in future efforts to improve destination‐specific recommendations in these areas. This communication attempts to make the process for making recommendations more transparent, while also recognizing that public health agencies with competing priorities and limited resources may often need to engage in iterative review processes that gradually improve recommendations over time. The approach outlined here serves as an interim solution, combining CDC's internal resources with externally available literature and data sources, until a more comprehensive follow‐up review can be accomplished.

The guidance published on the CDC Travelers' Health website is a tool to assist travel medicine providers, but in no way replaces the individual assessment of each traveler's risk.11,12 It is expected that health care providers will conduct a pre‐travel consultation to assess how these recommendations apply to individual travelers. Regardless of the risk level for typhoid, the web pages for all destinations contain recommendations about food and water safety. As enteric infections for which no vaccines are available, such as paratyphoid fever, become increasingly prevalent among travelers, attention to these basic food and water safety recommendations remains an essential part of travel safety.

The change in recommendations for 26 Eastern European and two Middle Eastern destinations is an encouraging reflection of reduced disease risk due to improvements in water and sanitation coverage. However, the fact that pre‐travel vaccination is still recommended for 175 (74%) of 238 destinations demonstrates that typhoid continues to remain a serious risk to travelers in many parts of the world. While reliable country‐specific data remains limited in some countries, this approach aims to provide a clearer picture of the potential risk of acquiring typhoid fever during travel by compiling and evaluating country‐specific data from a variety of sources instead of relying on regional trends. Similar approaches could be used to strengthen recommendations for other travel‐related diseases.


The authors of this manuscript represent a multidisciplinary team comprising many groups within CDC. We gratefully acknowledge the following Branches and individuals who assisted with this review: Ezra Barzilay, Clive Brown, Stephanie M. Delong, C. Virginia Lee, Kevin S. Liske, Benjamin L. Nygren, Katharine A. Schilling, Amanda Whatley, members of the Travelers' Health Branch, Waterborne Disease Prevention Branch, and Enteric Diseases Epidemiology Branch. We also thank Susanne Karlsmose of the National Food Institute, Technical University of Denmark, for providing data from the WHO Global Foodborne Infections Network.


The findings and conclusions in this report are those of the authors and do not necessarily represent the views of the Centers for Disease Control and Prevention.

Declaration of Interests

The corresponding author guarantees the integrity of the data and its analysis. Persons having a major part in manuscript preparation are acknowledged.


  • Summary findings on this work were also presented, by the same authors, at the 12th conference of the International Society of Travel Medicine, May 8–12, 2011, in Boston, MA, USA, as a poster.


View Abstract