Prevention of Gastrointestinal Illness Diarrhea, the leading cause of illness in travelers (Chap. 122), is usually a short-lived, self-limited condition; however, 40% of affected individuals need to alter their scheduled activities, and another 20% are confined to bed. The most important determinant of risk is the destination. Incidence rates per 2-week stay have been reported to be as low as 8% in industrialized countries and as high as 55% in parts of Africa, Central and South America, and Southeast Asia. Infants and young adults are at particularly high risk. A recent review suggested that there is little correlation between. | Chapter 117. Health Advice for International Travel Part 4 Prevention of Gastrointestinal Illness Diarrhea the leading cause of illness in travelers Chap. 122 is usually a short-lived self-limited condition however 40 of affected individuals need to alter their scheduled activities and another 20 are confined to bed. The most important determinant of risk is the destination. Incidence rates per 2-week stay have been reported to be as low as 8 in industrialized countries and as high as 55 in parts of Africa Central and South America and Southeast Asia. Infants and young adults are at particularly high risk. A recent review suggested that there is little correlation between dietary indiscretions and the occurrence of travelers diarrhea. Earlier studies of . students in Mexico showed that eating meals in restaurants and cafeterias or consuming food from street vendors was associated with increased risk. Etiology See also Table 122-3 The most frequently identified pathogens causing travelers diarrhea are toxigenic Escherichia coli and enteroaggregative E. coli Chap. 143 although in some parts of the world notably northern Africa and Southeast Asia Campylobacter infections Chap. 148 appear to predominate. Other common causative organisms include Salmonella Chap. 146 Shigella Chap. 147 rotavirus Chap. 183 and norovirus Chap. 183 . The latter virus has caused numerous outbreaks on cruise ships. Except for giardiasis Chap. 208 parasitic infections are uncommon causes of travelers diarrhea. A growing problem for travelers is the development of antibiotic resistance among many bacterial pathogens. Examples include strains of Campylobacter resistant to quinolones and strains of E. coli Shigella and Salmonella resistant to trimethoprim-sulfamethoxazole. Precautions Although the mainstay of prevention of travelers diarrhea involves food and water precautions the literature has repeatedly documented dietary indiscretions by 98 of travelers within the first 72 h after arrival