Consistent with previous studies regarding travel to China, our surveillance found that respiratory illnesses, specifically upper respiratory-tract infections and acute bronchitis, were the most common diagnoses in foreign travelers.12,14,15
This finding may be because of poor air quality associated with air pollution in Beijing, which was of concern in planning for the 2008 Beijing Games. Despite clean-air programs implemented to improve the levels of particulates in the air,16–18
respiratory illnesses in our study were the most common diagnoses in FV and the second most common in expatriates. However, the proportion of expatriates being diagnosed with respiratory illnesses during the 2008 Beijing Games was significantly less than expatriates in the same months during 2004–2007. One possible explanation for this decrease may be that the control programs were effective in reducing pollutants and respiratory irritants during the 2008 Beijing Games. Levels of pollution may have still been high enough to exacerbate conditions in naïve populations, such as FV, but may have alleviated some symptoms for long-term Beijing expatriate residents. Further studies into the specific control measures taken, the particulate reductions, the other environmental changes in Beijing during the 2008 Games, and their potential effects on health would be needed to confirm this hypothesis. In addition, expatriates with minor respiratory illnesses during the 2008 Beijing Games could have decided to avoid seeking health care at that time because of concerns that wait times might be long because of the influx of tourists.
The surveillance described here is unique, because it provides information on the expatriates living in Beijing during the 2008 Beijing Games. We believe this is the first Olympic or mass travel study to include expatriates in its surveillance system. In contrast with FV, the most common diagnoses for expatriates were sprains and strains, upper respiratory infections, and a number of dermatologic diagnoses. Because our surveillance system was limited in the type and depth of data collected, we could not discern if these injuries, respiratory infections, or dermatologic illnesses were related to the Olympic events. The expatriates may have spent more time outside as spectators of these events and therefore, may have been exposed to increased physical activity outdoors. Expatriates may also have retreated to locations outside the city of Beijing for part or all of the Olympic period and therefore, could have been exposed to different surroundings that may have increased the likelihood of injuries, insect bites, skin irritations, etc. However, many expatriate families would have been in Beijing by the end of August, because children were starting school.
Previous research has found that expatriates may have increased levels of stress, anxiety, and depression while living away from their home countries.11,12,19
However, in our study, the 2008 Olympics did not seem to have had an impact on psychological syndromes among expatriates. The rate of psychological syndromes did not differ significantly among expatriates during the 2008 Beijing Games (9%) and expatriates from 2004–2007 (10%). Future mass events would provide an opportunity to corroborate whether or not mass travel events, such as Olympic or Paralympic Games, affect the levels of stress, anxiety, and depression among expatriates.
Only half of all foreign visitors in our study sought PT health advice before their trip. Previous studies conducted among transit passengers in airports have found similar results.20–23
Although our study did not address why FV did not seek PT health advice, several possibilities may have influenced seeking this advice, including the duration of travel, travel confined to only cities, group travel, previous travel to China, or the FV's level of education or awareness of the importance of travel health.
The most common source of PT advice for FV from all countries was health-care providers. FV from the United States overwhelmingly consulted health-care providers; these findings highlight the importance of continued support and dissemination of information to U.S. health-care providers advising traveling patients. Our surveillance questions did not distinguish between health-care providers with travel-medicine training and those without, and therefore, educational messages should be targeted to all physicians and should focus on travel risks and health preparations necessary before international travel. The CDC's Yellow Book: Health Information for International Travel24
and the CDC Travelers' Health website (www.cdc.gov/travel
) represent the two principal mechanisms by which the CDC disseminates its recommendations for U.S. travelers. Further research is necessary to determine the extent to which U.S. health-care providers consult these sources for travel health recommendations.
The vaccinations CDC recommends for most travelers to China include hepatitis A, hepatitis B, typhoid, and influenza, when available. For travelers with prolonged outdoor exposure or travel to rural areas in China, CDC recommends rabies and Japanese encephalitis vaccines. The vaccines reported by U.S. travelers for this trip to China corresponded with these recommendations. The largest number of vaccines reported was for prevention of hepatitis A and hepatitis B.
The YF vaccine is a live virus vaccine that has been associated with rare but potentially severe adverse complications. CDC does not recommend it for travelers to China, because China is not a YF-endemic area. Our study was unable to determine why six FV (one from Australia and five from the Netherlands) reported receiving YF vaccine. Recent adverse events caused by the YF vaccine underscore the importance of administering the vaccine only to travelers visiting areas at risk.
Our study had several limitations. First, the study sites were convenience samples consisting of health facilities that were willing to participate, a subset of all possible health facilities for travelers to seek care while in Beijing. The patients may not have been representative of all travelers to China during the 2008 Beijing Games. There may have been differences in the populations at the clinics in 2008 versus the populations in the GeoS clinics in 2004–2007. Second, within each site, there may have been reporting biases. For example, the SOS clinic observers noted that one-third of the eligible patients could not participate in the study, because they spoke only Japanese. Thus, language barriers may have limited the number of respondents in each site. In addition, biases may have resulted from variations between the six clinics in staff, patient populations, diagnoses, and inclusion of eligible patients. Third, five of our clinics were permanent clinics in Beijing; therefore, our sample was biased toward expatriates. Fourth, very few VFRs participated in our study, even though large number of VFRs could have attended the 2008 Beijing Games. In addition, the vaccination data consisted of self-reports whose accuracy cannot be independently confirmed. This issue requires further research, because some studies have suggested that as many as 25% of patients who report receiving immunizations may actually be unprotected.25
In summary, the 2008 Beijing Games presented a complex public-health environment for travelers, because it was a mass travel event in a developing country. Our findings highlight the need for continued support and dissemination of information to health-care providers advising traveling patients. Based on our study, PT preparations for international events in China should focus on prevention of respiratory illness, injuries, and gastrointestinal illnesses, including gastroenteritis. To our knowledge, there have been no known studies of health outcomes among expatriates living in cities where mass travel events are taking place. Our findings provide insights on preparing and improving the health of expatriate populations during such events. Future considerations for mass travel events should include potential needs of populations already living in the event's location, such as expatriates, who may have unique medical needs.