9 cases of gastroenteritis occurring per person per year.34 A more detailed assessment of common symptoms of infection, especially respiratory symptoms, across both study sites would have been a useful addition
to our survey. A self-administered questionnaire design, MK-2206 supplier although appropriate to maximize the response rate in high volume airport surveys, limits the amount of detail obtainable and is also subject to recall bias. No case definitions were provided and symptoms were not objectively verified. Data on the reliability of self-reported infectious symptoms are scarce; however, one study has shown a high congruence between interview data and physician diagnoses (κ = 0.77) and high test–retest reliability (κ = 0.76).35 While the reported symptoms in our study are suggestive of an infectious etiology we cannot rule out non-infectious causes due to the non-specific nature of these symptoms. Reporting of two or more symptoms of infection may be a more reliable indicator of an infectious etiology for this purpose, and larger sample sizes are required to investigate the utility of this indicator. A larger sample of visitors departing Bangkok, as Angiogenesis inhibitor well as sampling travelers to other Asia-Pacific destinations would also have further strengthened our results. Our results also show that approximately 1 in 10 respondents reported a possible contact with a person with a fever, and that those residents departing Australia and visitors departing Thailand
who reported febrile contacts were more likely to self-report symptoms. Assuming effective contact with a febrile person, these respondents may be at higher risk of transmitting infection while traveling. Differences in travelers’
knowledge of their close contacts may explain the lack of independent significance of febrile contact in visitors departing Sydney. Resident respondents may be more likely to know their close contacts and have a better awareness of their contacts’ health status compared to travelers, clonidine and travelers to countries of higher disease endemicity may be more aware of the health of their close contacts. It is likely to be difficult for people to determine when they have been exposed to infection or to recall such events, and therefore such exposures are likely to be underestimated. During SARS, 56% of imported probable or suspected SARS cases developed symptoms after entry26 and the inclusion of self-reported contact may assist in algorithms for border control during emergency situations. The results from our representative survey contribute to the current global data on the burden of illness in travelers, particularly from the Asia-Pacific region, where few studies have been published. The proportion of travelers reporting common symptoms of infection is similar to studies from other regions and is consistent with models of disease transmission in that contact with a febrile person was the most important predictor of reported symptoms.