Incidence and Spectrum of Health Problems Among Travelers to Laos


Corresponding Author: Watcharapong Piyaphanee, MD, Department of Clinical Tropical Medicine, Faculty of Tropical Medicine, Mahidol University, 420/6 Ratchawithi Rd, Ratchathewi, Bangkok 10400, Thailand. E-mail:



The number of travelers visiting Laos has more than doubled in the last 5 years. Little is known about their pre-travel preparations and the incidence of health problems during their trips.


At three border posts between Laos and Thailand, travelers were invited to complete a study questionnaire. They were asked about their demographic profile, travel characteristics, pre-travel health preparations, and health problems during their stay in Laos.


From September 2011 to April 2012, 1,205 questionnaires from Thais and 1,191 from foreigners were collected. Approximately 60% of the travelers were male; the overall median age among the Thais was 43 years, and among the foreigners was 32 years. Most foreign visitors were from Europe (66.8%), followed by other Asian countries (19.0%) and North America (7.1%). Almost half of the foreigners (47.8%) traveled as individual backpackers, whereas the majority of Thais traveled as package tourists. Foreigners were more likely to trek, cycle, and swim during their trips. There were also significant differences in the average length of stay between foreigners (16.1 days) and Thais (3.8 days, p < 0.001). Health problems were reported in 24.9% of foreigners, the most common being diarrhea, cough, animal exposure, and fever. Only 6.1% of Thais reported health problems, the most common being cough and diarrhea. The relative risk adjusted for duration of stay was 1.63 (95% confidence interval: 1.01–2.64). Occurrence of health problems was associated with younger age group, non-Asian nationality, length of stay, and participation in adventurous activities.


Health problems are rather frequent among non-Thai travelers in contrast to Thais during their trips to Lao People's Democratic Republic. There were significant differences in terms of risk profile and prevalence of health problems between these two groups.

The Lao People's Democratic Republic (Lao PDR, Laos) is one of the few truly exotic destinations left in the world.[1] 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.[2] Most visitors were from Southeast Asia, with Thais accounting for more than 50% of all tourist arrivals in Laos.[2]

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

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

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.


From September 2011 to April 2012, approximately 3,500 travelers were invited to participate in the study; with the 70% response rate we finally collected and analyzed 1,205 questionnaires from Thais and 1,191 from foreigners. A majority of the travelers was male, and the overall median age was 43 years among the Thais and 32 years among the foreigners. Tourism was the main purpose for their current trip in both groups. Detailed demographic data are shown in Table 1.

Table 1. Demographic profile of participants
 ThaisForeignersp Value
Total participants (n = 2,396)1,2051,191 
Male (%)707 (58.9)711 (59.7)0.66
Female (%)494 (41.1)479 (40.3) 
Age (years)   
Mean (SD)43.6 (13.6)38.9 (16.2)<0.001
Median (range)  43 (16–83)   32 (17–87) 
European (%)All Thai793 (66.8) 
Asian (%)225 (19)  
North American (%)84 (7.1) 
Australian/New Zealander (%)65 (5.5) 
Others (%)20 (1.7) 
Main reason for travel  <0.001
Tourism (%)991 (82.4)1,062 (89.4) 
Business (%)101 (8.4) 24 (2.0) 
Visiting friends and relatives (%)95 (7.9)48 (4.0) 
Education and research (%)14 (1.2)13 (1.1) 
Other1 (0.1)41 (3.5) 
Travel style  <0.001
Package tourists (%)497 (41.5)47 (4.0) 
Backpackers (%)41 (3.4)561 (47.8) 
General tourists (%)491 (41.0)481 (41.0) 
Other (%)167 (14.0)85 (7.2) 

Travel Characteristics of Thais and Foreigners

The travel characteristics of the trip to Lao PDR differed significantly between Thais and foreigners. Almost half of foreigners (47.8%) traveled in Lao PDR as backpackers, whereas the majority of Thais traveled as package tourists. Only 3% of Thais traveled as backpackers. Foreigners tended to travel to several destinations, whereas Thais stayed rather in one area. Also, foreigners were more likely to engage in outdoor activities such as trekking, cycling, and swimming. The average length of stay for foreigners was four times longer than Thais (16.3 vs 3.8 days, p < 0.001). Detailed trip characteristics are shown in Table 2.

Table 2. Trip characteristics
 ThaisForeignersp Value
  1. PDR = People's Democratic Republic.

Duration of trip to Lao PDR (days)   
Mean (SD)3.8 (5.1)16.3 (39.8)<0.001
% of tourists travel 1–7 days92.50%49.10%<0.001
% of tourists travel >7 days7.50%51.10% 
Place visited   
Hueay Sai399 (33.1)492 (41.3)<0.001
Savanakhet406 (33.7)456 (38.3)0.01
Pakse430 (35.7)458 (38.5)0.11
Luang Prabang108 (9)  636 (53.4)<0.001
Vangvieng14 (1.2)425 (35.7)<0.001
Vientiane18 (1.5)528 (44.3)<0.001
Si Pandon60 (5.0)232 (19.5)<0.001
No. of places visited (n = 1,200)  <0.001
Only 1 area1,005 (83.8) 431 (36.5) 
2–4 areas194 (16.2)535 (45.3) 
5–7 areas 1 (0.1)208 (17.6) 
Activity during trips  <0.001
Trekking120 (10.0)256 (21.5) 
Cycling31 (2.6)385 (32.3) 
Swimming 8 (0.7)275 (23.1) 

Pre-Travel Preparation

Up to 20% of foreigners sought pre-travel consultation from travel clinics, whereas only less than 2% of Thais did so. Foreigners received significantly more vaccines than Thais (Table 3). About 50% of foreigners had been immunized against hepatitis A and tetanus, also often against hepatitis B (48.5%), typhoid (40.2%), rabies (22.2%), and Japanese encephalitis (15.7%). The vaccination rate was much lower among the Thais, with the two most common pre-travel vaccinations being tetanus and rabies at 6 and 4%, respectively. The differences were similar for malaria prevention; foreigners were more likely to use insect repellent (49.1% vs 10%, p < 0.001) and antimalarial chemoprophylaxis (26.4% vs 1.8%, p < 0.001).

Table 3. Pre-travel preparation for the trip
 ThaisForeignersp Value*
  • Data are number (%).

  • *

    Chi-square analysis.

Total participants1,2051,191 
Pre-travel consultation   
Travel clinic20 (1.7)251 (21.1)<0.001
General practitioner33 (2.7)281 (23.6)<0.001
Internet85 (7.1)311 (26.1)<0.001
Friend76 (6.3)113 (11.2)<0.001
Book31 (2.6)177 (14.9)<0.001
Pharmacist 7 (0.6)80 (6.7)<0.001
Others 6 (0.5)29 (2.4)<0.001
Pre-travel vaccination   
Rabies vaccine43 (3.6)264 (22.2)<0.001
HepA21 (1.7)605 (50.8)<0.001
HepB32 (2.7)578 (48.5)<0.001
Tetanus71 (5.9)598 (50.2)<0.001
Japanese encephalitis28 (2.3)187 (15.7)<0.001
Typhoid25 (2.1)460 (40.2)<0.001
Malaria preventive measures   
Repellent120 (10) 579 (49.1)<0.001
Taking malaria prophylaxis22 (1.8)312 (26.4)<0.001
Standby emergency treatment24 (2.0)148 (12.5)<0.001
None959 (79.6)494 (41.9)<0.001

Incidence of Health Problems Among Travelers in Laos

Of the 2,385 participants, 367 (15.4%) had health problems during their trips. Up to 25% of foreigners visiting Lao PDR had some health problems during their trips. Mild diarrhea (less than three loose stools per day and no mucous bloody stool) was the most common problem reported in 13.4% of foreigners, followed by classic travel diarrhea (more than three loose stools per day or passing one mucous bloody stool), cough, animal exposure, and fever.

Only 6.1% of Thais reported health problems; cough was most commonly reported followed by mild diarrhea. In view of their shorter duration of stay the adjusted RR was determined, but foreigners remained more often affected (adjusted RR: 1.63, 95% CI: 1.01–2.64, p < 0.05). Apart from the higher risk to develop any health problems in foreigners, they were more likely to have higher consequences (need doctor consultation and need admission) when compared with Thais. Detailed data are shown in Table 4.

Table 4. Incidence of health problems
 Thais (n = 1,202)Foreigners (n = 1,183) 
 n%n%p Value*
  • *

    Chi-square analysis.

  • By animal that potentially carries rabies virus.

Average duration of stay        3.8 days          16.3 days 
Health problems     
Any health problem736.129424.9<0.001
Mild diarrhea181.515913.4<0.001
Skin problems70.6363.0<0.001
Impact of health problems     
Bought medication221.8685.7<0.001
Visit doctor20.2252.1<0.001
Admit to the hospital0060.5<0.001

Risk Factors of Health Problems During the Trip to Laos

Age, nationality, length of stay, reason for travel, and activity during the trip influenced the incidence of health problems, whereas gender, travel style, and number of places visited had no effect. Activities during the trip (trekking, cycling, or swimming) appeared as risk factors; the more activities travelers participated in, the higher the risk (Table 5). There was no difference in health problems among travelers depending on border checkpoints.

Table 5. Relative risk of health problem during trip to Lao PDR
  Health problemNo health problem  
 Total (n)n%n%Relative risk (95% CI)Adjusted RR (95% CI)
  • PDR = People's Democratic Republic; CI = confidence interval; RR = relative risk.

  • *

    Included travelers from Europe, United States, Canada, Australia, and New Zealand.

Male97017117.679982.40.75 (0.60–0.94)1.00 (0.76–1.32)
Age group       
31–456937711.161688.90.32 (0.24–0.42)0.54 (0.38–0.77)
46–60584508.653491.40.24 (0.17–0.33)0.56 (0.36–0.87)
>60325185.530794.50.15 (0.09–0.24)0.30 (0.16–0.53)
Non-Thai Asian220167.320492.71.21 (0.67–2.07)0.48 (0.24–0.93)
Travelers from developed countries*93927229.066771.06.31 (4.81–8.36)1.63 (1.01–2.64)
Length of stay (days)       
4–73816015.832184.23.10 (2.15–4.45)1.38 (0.84–2.23)
8–15929223.430176.65.07 (3.64–7.07)1.73 (1.05–2.85)
16–3010210246.711753.414.46 (10.17–20.67)2.60 (1.44–4.70)
>30303042.74057.112.44 (7.30–21.07)3.48 (1.65–7.30)
Reason for travel       
Business125118.811491.20.49 (0.24–0.87)3.71 (1.51–8.47)
Visiting friends and relatives139128.612791.40.48 (0.25–0.83)2.11 (0.90–4.52)
Education and research27311.12488.90.63 (0.15–1.81)1.51 (0.32–5.02)
Other4224.84095.20.25 (0.04–0.83)1.61 (0.24–6.27)
Travel style       
General tourist971889.188390.911
Backpackers60122236.937963.15.88 (4.48–7.77)1.20 (0.80–1.80)
Package tourist542448.149891.90.89 (0.60–1.29)1.53 (0.95–2.45)
Other252124.824095.20.50 (0.26–0.90)0.24 (0.09–0.59)
No. of places visited       
Only 1 area1,431876.11,34493.911
2–4 areas72818625.554274.55.30 (4.05–7.00)1.73 (1.14–2.62)
5–7 areas2099244.011756.012.15 (8.58–17.25)1.54 (0.87–2.71)
No trekking/cycling/swimming1,6931116.61,58293.41 
Yes69225637.043663.08.37 (6.56–10.74) 
Activity (trekking/cycling/swimming)       
1 Activity3819625.228574.84.87 (3.59–6.59)2.45 (1.71–10.81)
2 Activities1849048.99451.113.84 (9.77–19.67)3.51 (2.25–5.49)
3 Activities935862.43537.623.96 (15.17–38.38)6.02 (3.39–10.81)


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;[8] 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;[12] 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.[13]

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.


We would like to thank all the staff members of the Port Health Office at Chiang Khong in Chiang Rai Province, Mukdahan in Mukdahan Province, and Chong Mek in Ubon Ratchathani Province for their help during data collection. We also thank Mr Paul Adams and Mr Gary Hutton of the Faculty of Tropical Medicine, Mahidol University, for reviewing this manuscript.

Declaration of Interests

The authors state that they have no conflicts of interest.