The Lao People's Democratic Republic (Lao PDR, Laos) is one of the few truly exotic destinations left in the world. According to the Lao Statistics Bureau, there were 1.1 million visitors in 2005, and this number more than doubled to 2.7 million arrivals in 2011. Most visitors were from Southeast Asia, with Thais accounting for more than 50% of all tourist arrivals in Laos.
Several studies have been conducted to report the incidence of health problems among travelers to Southeast Asia; however, these findings assessed overall regional data. They were not specific to Laos, as only 6% to 20% of participants in those studies had traveled there.[3-5] Health risk among travelers to Southeast Asia may vary from country to country.
Therefore, we conducted this study to determine health problems among Thai and other foreign visitors to Laos. Secondary objectives were to assess pre-travel preparations, vaccination rate, and risk factors for health problems.
Materials and Methods
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- Materials and Methods
- Declaration of Interests
This cross-sectional questionnaire-based study was conducted at three border checkpoints on the Thai side of the Thai–Lao border. Data were collected from Thai and other foreign travelers, aged 18 years and older, who had just completed their trip to Laos. Travelers with Laotian nationality and 1-day trip travelers were excluded. The study questionnaire was drafted, reviewed, and revised. It also had been tested before actual data collection to ensure its validity and reliability. The final version of the questionnaire was printed in Thai and English, and comprised three parts, ie, demographic information about the travelers, travel and activities during the trip, and health problems during their stay in Laos.
There are 12 border checkpoints between Thailand and Laos, and three of the main ones are Chiang Khong in Chiang Rai Province, Mukdahan in Mukdahan Province, and Chong Mek in Ubon Ratchathani Province. These three were selected to represent travelers returning to Thailand from Northern, Central, and Southern Laos, respectively. The sample size was calculated according to the main objective, which was to determine the incidence of health problems among Thais and foreigners visiting Laos. Because there was no previous study, the incidence was estimated to be about 10% according to previous study in Southeast Asia,[3, 4] together with the number of travelers visiting Laos in 2010 from the Immigration Police. To achieve a 95% confidence level, at least 380 Thais and 380 foreigners are required at each border checkpoint, with a total of 1,150 subjects in each group for three checkpoints.
The research protocol and questionnaire were approved by the Ethics Committee of the Faculty of Tropical Medicine, Mahidol University. During data collection, the investigator team invited any traveler upon arrival to Thailand to participate in the study. All participants were informed of the study's objective and verbally consented before personally filling the questionnaires. If needed, the investigator team was available to assist. No participant-identifiable data were recorded in the questionnaire to maintain confidentiality.
Statistical analysis was conducted using spss for Windows, version 10.0.7 (SPSS Inc., Chicago, IL, USA) software. Continuous data were presented as mean with standard deviation (for normally distributed data) or median with range (for non-normally distributed data). Categorical data were presented as numbers and percentages.
The t-test was used to compare means of two groups, whereas the chi-square test was used for comparison of categorical data, as appropriate. Relative risk (RR) and 95% confidence interval (CI) were calculated to determine potential factors associated with health problems, using generalized linear model. Factors with a p value of <0.10 in univariate models were considered eligible for the multivariate analysis to calculate adjusted RR. In this study, a p value of <0.05 was considered statistically significant.
- Top of page
- Materials and Methods
- Declaration of Interests
To our knowledge, this was the first survey focusing on health problems among travelers visiting Laos. Overall 25% of foreigners (non-Thais) reported some health problems. Diarrhea was the most common problem reported in 20% of our participants and this proportion was a close match to previous studies in Thailand.[4-6] Particularly surprising is that 1% had been bitten by an animal within the average 16-day stay. This rate is markedly higher when compared with previous studies from Thailand, which reported the rate around 0.67% to 1.1% per month.[3, 7] This is possibly associated with the considerable proportion of backpackers in our population. To note, only 6% of dogs in Laos were vaccinated, and up to 64% of animal specimens tested positive for rabies; so the risk of exposure to rabies virus in Laos was high. Moreover, the availability of effective postexposure treatment (rabies immunoglobulin and vaccine) remains a problem in Laos,[8, 9] potentiating the threat of rabies among travelers. Therefore, appropriate rabies risk assessment and risk management should be included in pre-travel visits.
Although only 5% of foreign travelers had fever during their trips to Laos, it should not be neglected, because fever might be a clue to potential life-threatening diseases such as malaria and dengue fever, which are still prevalent in Laos, and travelers in this area are inevitably at risk.[10, 11]
In this study, we were able to demonstrate the major differences in travel characteristics between Thai and non-Thai travelers visiting Laos. Apart from that, Thai and Lao people share a similar culture and cuisine, and possibly have similar background immunity. Therefore, these factors might explain why the prevalence of health problems among Thais was lower than that among non-Thais, even though Thais were less likely to have pre-travel consultation and had less vaccination.
Travel health practitioners cannot develop a rigid guideline for any traveler to one specific destination; recommendation should be “tailor-made” according to their risk profile. According to this report, nationality clearly determines travel characteristics and also health problems during the trip. One may assume that travelers visiting neighboring countries may not need extensive pre-travel counseling and vaccines, whereas that might be essential to travelers from distant regions. However, this concept is not always true because health risks are too complex to consider as non-threatening based solely on the short distance between home and destination. For example, most Singaporeans have neither natural immunity nor vaccination against Japanese encephalitis; so when they travel to nearby countries, such as Malaysia or Thailand, they are still at risk. The report in 2012 confirmed that the majority of dengue infections in the United States were contracted from neighboring Mexico and the Caribbean.
According to the results of multivariate analysis, we can confirm that the occurrence of health problems is associated with younger age, longer duration of stay, and participation in adventurous activities (trekking, cycling, or swimming). These factors should be taken into account during pre-travel counseling because they will be helpful when considering vaccines, chemoprophylaxis, etc.
There are some limitations to this study. First, when the questionnaire study was conducted, travelers had just ended their travel to Laos, ie, at the border, so we might have missed some health problems that have long incubation periods, or those travelers who had acquired some infection just before leaving Laos and were not yet showing symptoms. Second, as this was a self-reported questionnaire study, recall bias is an inherent limitation. It is possible that travelers may have underreported or overreported some health problems. However, this bias should be minimal in cases such as animal bite and diarrhea because the event would be obvious and not easily forgotten.
In conclusion, this study confirms that diarrhea is a common problem among travelers in Laos, and that there is a potentially high risk of exposure to rabies. Travelers from Thailand clearly had different risk profile when compared with travelers from industrialized countries. Additional research that focuses on travelers' health within specific regions is immediately needed.