Andreas Keller1, Markus Frey, Hans Schmid, Robert Steffen, Thomas Walker, Patricia Schlagenhauf. 1. Division of Epidemiology and Prevention of Communicable Diseases, WHO Collaborating Centre for Travellers' Health, Institute of Social and Preventive Medicine, University of Zurich Travel Clinic, CH-8001 Zurich, Switzerland. andreas.keller@access.uzh.ch
Abstract
BACKGROUND: In industrialized countries, typhoid fever occurs mainly in returned travelers. To determine the need for preventive strategies, eg, for vaccination, continuous monitoring is needed to assess where the risk for travelers is highest. METHODS: To investigate where the risk for travelers to acquire typhoid fever is highest, 208 patients with typhoid fever and recent travel were matched with travelers' statistics collected by the Swiss Federal Office of Statistics. RESULTS: At the beginning of the study period, up to 30 infections with Salmonella typhi were recorded per year in Switzerland. Since 2001, less than 15 confirmed cases per year occurred. A majority of the 208 (88.5%) typhoid cases were associated with recent travel. Countries with highest risk were Pakistan (24 per 100,000), Cambodia (20 per 100,000), Nepal (14 per 100,000), India (12 per 100,000), and Sri Lanka (9 per 100,000). CONCLUSIONS: We found that over a 12-year period (1993-2004), the travel-associated risk of typhoid fever is highest for destinations in the Indian subcontinent. All other regions showed a decline, most markedly in southern Europe. Our results suggest that typhoid fever vaccination should be recommended for all travelers to countries in South Asia. Otherwise, vaccination of tourists to frequently visited low- and intermediate-risk areas is not necessary, unless there are behavioral risk factors.
BACKGROUND: In industrialized countries, typhoid fever occurs mainly in returned travelers. To determine the need for preventive strategies, eg, for vaccination, continuous monitoring is needed to assess where the risk for travelers is highest. METHODS: To investigate where the risk for travelers to acquire typhoid fever is highest, 208 patients with typhoid fever and recent travel were matched with travelers' statistics collected by the Swiss Federal Office of Statistics. RESULTS: At the beginning of the study period, up to 30 infections with Salmonella typhi were recorded per year in Switzerland. Since 2001, less than 15 confirmed cases per year occurred. A majority of the 208 (88.5%) typhoid cases were associated with recent travel. Countries with highest risk were Pakistan (24 per 100,000), Cambodia (20 per 100,000), Nepal (14 per 100,000), India (12 per 100,000), and Sri Lanka (9 per 100,000). CONCLUSIONS: We found that over a 12-year period (1993-2004), the travel-associated risk of typhoid fever is highest for destinations in the Indian subcontinent. All other regions showed a decline, most markedly in southern Europe. Our results suggest that typhoid fever vaccination should be recommended for all travelers to countries in South Asia. Otherwise, vaccination of tourists to frequently visited low- and intermediate-risk areas is not necessary, unless there are behavioral risk factors.
Authors: Kashmira A Date; Anna E Newton; Felicita Medalla; Anna Blackstock; LaTonia Richardson; Andre McCullough; Eric D Mintz; Barbara E Mahon Journal: Clin Infect Dis Date: 2016-04-18 Impact factor: 9.079
Authors: Adrián Sánchez-Montalvá; Ángela Martínez-Pérez; José Antonio Pérez-Molina; Juan José González-López; Rogelio Lopez-Vélez; Fernando Salvador; Irene Sánchez; Anna M Planes; Israel Molina Journal: Medicine (Baltimore) Date: 2015-05 Impact factor: 1.889