Travel‐Related Mosquito‐Transmitted Disease Questionnaire Survey among Health Professionals in Taiwan

Hsien‐Liang Huang MD, MSc, Tai‐Yuan Chiu MD, MHSci, Kuo‐Chin Huang MD, PhD, Shao‐Yi Cheng MD, MSc, DrPH candidate, Chien‐An Yao MD, MPH, Long‐Teng Lee MD, PhD
DOI: 34-38 First published online: 1 January 2011


Background Health‐care professionals can help travelers by providing accurate pre‐travel counseling for mosquito‐transmitted diseases such as malaria, yellow fever, and dengue fever. Governments and international organizations will benefit from knowledge survey among health professionals in this field to promote the development of travel health profession. This study investigates physicians' and nurses' knowledge regarding malaria, yellow fever, and dengue fever.

Methods A cross‐sectional questionnaire survey was distributed to physicians and nurses in Taiwan interested in travel medicine between April and September of 2008. The self‐administered, single‐choice questionnaire evaluated knowledge regarding epidemiology, prophylactic medication for malaria, yellow fever, and dengue fever, and vaccinations for yellow fever as well as background information of participants.

Results Complete information was collected from 82 physicians and 203 nurses. (Out of 289, effective response rate = 99.9%). The mean percentage of accurate responses was similar for all three diseases: malaria 67.3% (range, 16.8%–90.5%); yellow fever 65.4% (39.6%–79.3%); and dengue fever 74.4% (14.4%–96.5%). The items with the lowest accuracy were (1) behavior of the dengue fever vector Aedes aegypti mosquito (14.4%) and (2) incubation period of malaria (16.8%). There were 60.4% participants who did not know the current revaccination interval for the yellow fever vaccine. The average knowledge scores for all three diseases were statistically significantly higher in the physician group.

Conclusions Analysis of the results revealed significant deficits in travel medicine knowledge among health‐care providers. Emphasis on continuing medical education for disease vector behavior, prophylactic drug prescription, and preventative vaccination is important to travel safety. Health professionals in Taiwan should actively participate in the International Society of Travel Medicine to follow the international standard of travel medicine practitioners. This type of survey should be adopted in other countries which would be helpful in improving the quality of care for travelers.

Health‐care providers play an essential role in ensuring healthy and safe travel. Although the International Society of Travel Medicine (ISTM) had tried to encourage the global professional development of travel medicine by promoting the ISTM Certificate of Knowledge Program, many countries, including Taiwan, are still not actively participating in the ISTM. 1,2 The frequency of international travel has increased dramatically, making pre‐travel health advice and post‐travel health issues the subject of frequent office visits for many health‐care professionals. 3 Therefore, health‐care providers should have a general knowledge of travel medicine and be able to provide both adequate pre‐travel consultation and post‐travel care. 4 In Taiwan, pre‐travel health advice such as yellow fever vaccination and antimalaria drugs are mainly given in 11 hospitals contracted with Center for Disease Control of Taiwan. The health professionals in these hospitals are the main population of travel health providers in Taiwan.

The field of travel medicine includes knowledge regarding numerous diseases, epidemiology, and vaccination issues. 5,6 The scope of the travel medicine becomes increasingly more complex when factors such as patients' chronic health issues, changes in disease vectors due to climate and environment change, new medication and vaccine developments, and rising drug resistance are taken into account. Education for health‐care providers may not provide adequate training prior to initiating travel‐related consultations. As a result, physicians, nurses, pharmacists, and other health‐care professionals may require updates in their knowledge when advising travelers. Many questionnaire survey studies assessed the knowledge, attitude, and practices of travelers, 7–9 but there are relatively few studies which aim to assess the knowledge of health‐care professionals. 10,11 The information obtained from such a study would provide invaluable data for governments and international organizations that could be used to promote the development of travel health profession.

Mosquito‐transmitted diseases such as malaria, yellow fever, and dengue fever, are commonly discussed during pre‐travel counseling. 12–15 Basic knowledge about the diseases, vaccines, and preventative medications is important for health professionals. 16,17 The Body of Knowledge for the Practice of Travel Medicine by ISTM and the fact sheets of these diseases in the World Health Organization (WHO) also included many details about mosquito‐related diseases. 18 This study investigated Taiwanese physicians' and nurses' knowledge of malaria, yellow fever, and dengue fever. The results can help government and medical care systems promote the professional development of travel medicine and enhance the quality of travelers' health care.


Design and Participants

This study represents a cross‐sectional questionnaire survey of physicians and nurses interested in travel medicine. The Training Center for Travel Medicine from the National Taiwan University held three nationwide one day seminars on travel medicine in the northern, southern, and eastern part of Taiwan from April to September of 2008. The seminars were promoted in hospitals interested in travel medicine nationwide and advertized on internet websites. These seminars were also supported by the Center for Disease Control of Taiwan and the Taiwan Association of International Health. Participants were mainly hospital‐based physicians and nurses. The questionnaire and consent forms were administered to all participants prior to the seminars and were returned before the start of the seminars. All the study procedures were approved by the Ethical Committee of the National Taiwan University Hospital.

Questionnaire Design

The self‐administered, single‐choice questionnaire included four parts and started with an assessment of general background information. The remaining three parts included 17 questions regarding knowledge of the epidemiology, preventative medications for malaria (6 questions), yellow fever (4 questions), dengue fever (5 questions), and vaccine information for yellow fever (2 questions). The questionnaire was based upon personal practice experiences and designed after a careful literature review. Five experts tested the content validity, while the face validity was tested by two physicians and three nurses. The scores from the knowledge of each disease were summed by assigning each correct answer one point.

Statistical Analysis

Data management and statistical analyses were performed using SPSS 11.0 software. Frequency distributions described the demographic data. The chi‐square test was used to compare the percentage of correct answers between physicians and nurses for each question, and the t‐test was used to compare the overall scores between the two groups. A p value less than 0.05 was considered statistically significant.


A total of 289 health‐care providers (86 physicians and 203 nurses) who were interested in travel medicine were given the questionnaire, and all responded. After eliminating four incomplete questionnaires, 285 were included in the final analysis (85 physicians and 200 nurses). The mean age was 37.4, and no health‐care provider had received any prior certification in travel medicine.

Malaria Questionnaire

Table 1 shows the percentage of accurate responses for knowledge of malaria in the physician and nurse groups. The mean percentage for accurate responses to malaria questions was 67.3% (range, 16.8%–90.5%). The accuracy was lowest for the two questions: (1) duration of mefloquine use as prophylaxis for malaria, and (2) the longest incubation period of malaria due to the dormant phases of Plasmodium vivax and Plasmodium ovale. The most often chosen, incorrect answer (21.2% physicians and 33.5% nurses) regarding the duration of prophylactic mefloquine use was one week before travel and continue using until one week after leaving malarious area. The chosen answers to the question about malaria's incubation period were distributed evenly: 1 month (23.2%), 3 months (26.7%), 6 months (16.5%), 1 year (16.5%), and not sure (16.8%).

View this table:
Table 1

Comparison of physicians' and nurses' knowledge of malaria

Percentage of correct answers (%)
ItemsTotalPhysicians (n = 85)Nurses (n = 200)p Value*
1. Transmission mode98.998.899.01.000
2. Infectious agent 74.789.468.5<0.001
3. Common symptoms90.591.890.00.642
4. Behavior of disease vector82.877.6850.132
5. Duration of mefloquine use 406031.5<0.001
6. Incubation period16.822.414.50.105
  • Data are expressed as percentages.

  • *The p value was calculated using the chi‐square test for the analysis between the physician and nurse groups.

  • Items with p value <0.05.

Yellow Fever Questionnaire

The mean percentage of accurate responses for the yellow fever questions was 65.4% (range, 39.6%–79.3%), and Table 2 demonstrates the results of the two groups. There were four questions with an accuracy between 70 and 80%, and two questions with an accuracy less than 60%. Only 39.6% of health professionals knew the revaccination interval for the yellow fever vaccine. Approximately 22% of health‐care providers reported 5 years as the current suggested revaccination interval, and 24% answered not sure.

View this table:
Table 2

Comparison of physicians' and nurses' knowledge of yellow fever

Percentage of correct answers (%)
ItemsTotalPhysicians (n = 85)Nurses (n = 200)p Value*
1. Transmission mode74.483.570.50.021
2. Infectious agent 71.690.663.5<0.001
3. Common symptoms 79.392.973.5<0.001
4. Timing of initial vaccination before travel57.265.953.50.053
5. Revaccination interval39.643.538.00.383
6. Epidemic area 70.581.266.00.010
  • Data are expressed as percentages.

  • *The p value was calculated using the chi‐square test for the analysis between the physician and nurse groups.

  • Items with p value <0.05.

Dengue Fever Questionnaire

Table 3 shows the items surveyed and accurate response percentages for both groups regarding knowledge about dengue fever. The mean percentage of accurate responses to the dengue fever questions was 74.4% (range, 14.4%–96.5%). One item (the behavior of the vector Aedes aegypti mosquito) had a very low accuracy (14.4%). Approximately 60% of physicians and 58% of nurses selected the answer that the mosquito is only active at dusk.

View this table:
Table 3

Comparison of physicians' and nurses' knowledge of dengue fever

Percentage of correct answers (%)
ItemsTotalPhysicians (n = 85)Nurses (n = 200)p Value*
1. Transmission mode96.598.895.50.291
2. Infectious agent 78.292.972<0.001
3. Common symptoms 94.498.892.50.045
4. Behavior of disease vector 14.427.19.0<0.001
5. Epidemic area 88.496.5850.006
  • Data are expressed as percentages.

  • *The p value was calculated using the chi‐square test for analysis between the physician and nurse groups.

  • Items with p value <0.05.

Knowledge Scores

Figure 1 shows physicians had statistically significant, higher scores for all three diseases. The average score was highest for knowledge about dengue fever in both the physician (dengue fever vs yellow fever vs malaria = 0.83 vs 0.76 vs 0.73) and nurse (0.71 vs 0.61 vs 0.65) groups.

Figure 1

>Knowledge scores of the three diseases for physicians and nurses; *p value <0.05.


This study represents one of the first nationwide surveys focusing on health‐care professionals' knowledge of travel medicine and provides valuable information for the burgeoning travel medicine profession in Taiwan, as well as other countries looking to improve the quality of medical care for their traveling citizens.

Understanding the behavior of disease vectors can help health‐care professionals provide appropriate suggestions to travelers and help create a safe travel schedule. 16 Advising travelers to protect against vector‐borne diseases is a crucial component of any pre‐travel consultation. This advice is especially important in situations where there are no effective vaccines or prophylactic drugs available (eg, dengue fever). Travelers may be able to modify their schedules according to peak biting activity, such as twilight periods for malaria or daylight hours for dengue fever. Knowledge regarding the Anopheles mosquito was high (82.8% accuracy), while knowledge about the A aegypti mosquito was quite low (14.4%). Training programs in medical schools often place more emphasis on the diagnosis and treatment of disease than on the microbiology of disease and disease vector behavior. As a result, health‐care providers may prescribe appropriate medications or vaccines for travelers but are unable to provide individualized and comprehensive advice regarding suitable travel plans. These study results illustrate the weaknesses in medical education and serve as a reminder of the importance of adequate education on vector behaviors during travel medicine professional development.

Cases of dengue fever and dengue hemorrhagic fever had been reported, and are widespread in South Pacific Asia. National Statistics demonstrated that 550,000 Taiwan people travel to this area annually. There were a total of 488 dengue indigenous cases reported in Taiwan in 2008, especially southern part of Taiwan was affected the most. 19 Moreover, the imported cases increased from 109 in 2006 to 204 in 2009 (179 in 2007, 226 in 2008). Taiwan's government announced a 4‐year dengue fever plan with strategies for prevention as well as cooperation from other countries to control this disease. The government tried to strengthen education and training for the medical profession, and these government actions may account for the high dengue fever knowledge scores seen in this study. WHO declared Taiwan a malaria eradicated region in December of 1965. There are only a small number of imported cases since that time, and P ovale causes most infections here. According to the study results, physicians and nurses are not familiar with the use of antimalarial drugs or the incubation period of malaria. Health‐care professionals need to provide travelers with country‐specific information regarding the risks of infectious diseases. 20,21 Hence, each country might need to establish its own standard for the travel medicine profession based upon knowledge of certain infectious agents.

Incorrect answers to questions about malaria and yellow fever were common in this study, and the mean percentages of accurate responses were only 67.3 and 65.4%, respectively. Over 40% of physicians who could be responsible for prescribing antimalarial drugs and yellow fever vaccines gave wrong answers for questions dealing with mefloquine use, revaccination intervals for yellow fever, and the suggested timing of the initial yellow fever vaccine prior to travel. A previous study in Taiwan revealed that the yellow fever vaccine and prophylactic drugs for malaria were among the main needs of travelers visiting the travel medicine clinic. 22 Providing accurate and detailed information about the different vaccines and medications is the backbone of travel medicine, and health‐care providers should have adequate knowledge on these topics. These findings suggest that there is an urgent need to enhance medical staffs' knowledge and clinical experiences in the field of travel medicine and to develop standards for the field of travel medicine.

There are several limitations in this study. First, the clinical experience of each health‐care provider was not included or assessed in the survey. However, there were no formal training programs or certificate on travel medicine in Taiwan at the time of the study, and previous practices could not represent the related experiences in travel medicine. Second, the knowledge of pharmacists was not investigated in the survey. Given pharmacists are easily assessed by travelers, further study is needed. Third, different countries had different available vaccines and drugs, and the prevailing infectious diseases were also region‐specific. The findings here should be applied with modification to other countries. Fourth, those who attended the conferences may be particularly interested in travel health, and the generalizability of the results to the rest of the population of travel health providers should be of some concern. Finally, a post‐survey questionnaire would be informative to decide whether the proposed training significantly improved relevant knowledge which is not conducted in the current study.

In conclusion, this investigation revealed that health‐care providers did not have enough knowledge in travel medicine. The health professionals in Taiwan should actively participate in ISTM urgently and follow the international standards of travel medicine practitioners. The government and the Taiwan Association of International Health must work together to promote the professional development of travel medicine, which would ultimately improve the quality of care for travelers. A survey such as this one should be utilized in other countries where travel medicine is under development.


This study has been supported by the Center for Disease Control, Taiwan.

Declaration of Interests

The authors state that they have no conflicts of interest to declare.


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