Symptoms of infection in the 2 weeks prior to departure were commonly reported in our cross-sectional sample of travelers within the Asia-Pacific
region. Overall, approximately 1 in 4 respondents reported at least one and 1 in 20 reported two or more symptoms of infection, a significant finding considering the magnitude of air passenger movements within the region. In 2007, 5.8 million travelers departed Australia on flights to Asian destinations and a further 700,000 travelers departed Thailand for Australia.21 Reporting of symptoms was greater in respondents departing Bangkok. Studies from other regions have also shown significant differences in symptom reporting between travelers returning from destinations find more considered high and low risk.8,12,22 No significant differences in symptoms were reported in a study of Taiwanese travelers returning from tropical and non-tropical regions of Asia.10 Emerging infectious diseases, including drug-resistant strains, have been reported from both developing and developed regions, and studies of symptoms of infection in travelers from both these regions are of global public health
interest.23 Our study included both departing visitors and residents which may limit comparisons with other traveler studies. We found that departing residents were as likely to report two or more symptoms as departing visitors and more likely to report febrile contacts. However, independent www.selleckchem.com/products/Erlotinib-Hydrochloride.html predicators of reporting symptoms differed by these groups. The incidence of illness in travelers prior to commencing
their trip has not been the focus of previous studies and our results support the carriage of infections in both departing and returning travelers. The general symptoms of infection assessed in this study are common to a range of globally prevalent diseases, and it can be expected that a proportion of travelers departing from their country of residence will report symptoms of infection. Our findings also highlight the importance of social contact and human behavior in the spread of infectious disease during travel. We acknowledge that MRIP causality cannot be concluded from a cross-sectional study, and social contacts on the day prior to interview, as obtained in this study, are not likely be causally related to the symptoms reported in the 2 weeks prior to interview. However, the assessment of recent behavior produces the least recall bias while providing a proxy measure of typical levels of social contacts over the 2 weeks prior to departure. Sore throat was the most common symptom reported in our study. Comparable studies report a low prevalence of respiratory symptoms in cross-sectional samples of travelers ranging from 2.2% to 4%.8–10 Fieldwork during the winter months, when rates of respiratory infections are greater, may explain the high level of reporting in our study.