June 2019, Volume 69, Issue 6


Dengue fever in Southern of Vietnam: A survey of reported knowledge, attitudes, and practices

Authors: Pol Van Nguyen  ( Department of Pharmacy Administration, Faculty of Pharmacy, University of Medicine and Pharmacy at Ho Chi Minh City, Vietnam )
Trung Quang Vo  ( Department of Economic and Administrative Pharmacy, Pham Ngoc Thach University of Medicine )
Thoai Dang Nguyen  ( Department of Pharmaceutics and Biopharmaceutics, Pham Ngoc Thach University of Medicine )
Thuy Tran Chung Phan  ( Ear-Nose-Throat Hospital, Ho Chi Minh City, Vietnam )
Nam Van Ho Phan  ( Department of Analytical Chemistry and Druf Quality Control, University of Medicine and Pharmacy, Ho Chi Minh City, Vietnam )


Objective: Dengue fever (DF) is an acute infectious disease with high incidence in tropical countries, such as Vietnam, where dengue prevention is a challenge for the health sector, government, and policy makers. The aim of this study was to assess the knowledge, attitudes, and practices in southern Vietnam and explore their relationships with the characteristics of the people.
Methods: A cross-sectional study was conducted, using interviews with 1,906 urban participants and 493 rural participants in southern Vietnam in July 2018.
Results: The study found a lack of knowledge regarding DF symptoms, with only 37.2% having a good level of knowledge, although 57.1% had good attitudes and 56.1% had good practices. Television (85.4 %) and the internet (69.5%) were the two main sources of information, and information provided by healthcare professionals was low. Participants with good knowledge had approximately 1.7 times the probability of having a good attitude and 5.0 times the probability of having good practices of those without. Urban participants had 1.3 times the level of knowledge than those in rural areas (p = 0.025), while the quality of attitude scores of rural participants was 1.3 times (p = 0.029) that of urban participants.
Conclusion: Improvements in knowledge of DF, as well as in attitudes and practices toward dengue, are required, such as might be achieved through increased publicity and knowledge dissemination.

Keywords: Community, Dengue, Knowledge, Attitude, Practice, Vietnam. (JPMA 69: S-118 (Suppl. 2); 2019)


Dengue fever (DF) is a disease caused by four dengue virus serotypes and transmitted mainly through mosquito bites, especially those of Aedes Aegypti.1 DF has emerged as an important problem which is prevalent in many countries worldwide, with an estimate of 2.5 billion people living in high-risk areas. In 2012, the World Health Organization (WHO) estimated that 50 to 100 million people were infected, with more than 22,000 deaths each year, mostly children. 1,2 Using a cartographic approach, Samir Bhatt et al estimated that there are 390 million dengue infections worldwide per year.3Vietnam is a tropical monsoon-climate country, which offers favourable conditions for mosquito breeding, and thus for developing infectious disease like dengue. 1 The incidence of dengue has increased continuously, from 32.5 cases per 100,000 people in 2000 (24,434) to 78 cases per 100,000 people in 2011 (69,680 cases). Over 85% of cases and 90% of deaths due to dengue are in southern Vietnam, 4 making Vietnam an endemic country for dengue. A study in Vietnam estimated that the economic burden of DF was at least 94.9 million USD, and the actual number could be much greater. 5 Due to Vietnam's dengue outbreaks, prevention is becoming a top social concern, particularly as there is no specific treatment for DF. The most promising approach, of finding vaccines against all four serotypes of dengue virus, has achieved some progress, but these are not yet available in the Vietnam market. DF-prevention programmes are therefore extremely important, much more so than treatments, and the Vietnamese government has instituted several strategies to promote the prevention of dengue by reducing dengue vectors. The critical role of community education in the improvement of knowledge, attitudes, and practices (KAP) has been demonstrated,6 and there were studies of interest on this issue in both high and low incidence countries, including France, India, Indonesia, Thailand, Malaysia, and Nepal.7-13 A study conducted by Dhimal et al, in Nepal, in areas with a similar climate to Vietnam, showed that only 12% of participants had good knowledge and only 37% good practices regarding DF, although 83% had a good attitude. 7A KAP study istherefore necessary to assess the effectiveness of educational efforts and to understand the KAP of people regarding the prevention of DF in light of WHO recommendations4 and the actual conditions and socioeconomic changes occurring in Vietnam.14-16 The knowledge gained from this survey will guide public administrators in planning, designing, and implementing initiatives, programmes, and policies related to dengue prevention, which may help to solve the growing problem of dengue infection. To date, there have been no studies on the KAP of the Vietnamese population; this study therefore aimed to assess the KAP among the Vietnamese residents regarding DF, in order to create a basis for improving and developing policies related to DF prevention in Vietnam.

Subjects and Methods

A cross-sectional survey was conducted from July to September 2018 in Southern Vietnam to measure the KAP regarding dengue and to identify predictive factors.

Study Setting and Geographic Location

At the time this study was conducted, the total population of Vietnam was approximately 92.6 million. According to government statistics, 32 southern locations (including three central cities and 29 provinces) were considered as endemic areas for dengue in Vietnam and were therefore chosen for data collection. These 32 provinces were divided into four areas, depending on their economic and geographic situations: central coastal area (total population 9.2 million in 2016), central highlands (5.7 million), south-eastern area (16.4 million), and Mekong River Delta (17.6 million).17 Sample size was calculated using the following formula

N = Zα/2 × P(1-P) (a)18 / d2

N'= Populationofthearea × 385 (b) / 5.7

A single population proportion formula (a) was used to estimate the minimum sample size. The following assumptions were made: 90% confidence interval (Zα/2 = 1.96), 50% with good dengue-related KAP, and 5% margin of error. The calculated sample sizes were 271 for the central highlands, 440 for the central coastal area, 780 for the south-eastern area, and 840 for the Mekong River Delta, based on formula (b). In total, the study required a minimum of 2,331 participants. Assuming 20% missing or invalid results, 2,797 questionnaires were administered. The study tool was a questionnaire used to explore the KAP regarding dengue was adapted and re-designed from two previous studies. 7,8The initial version was pre-tested on a pilot population of 200 rural and urban residents throughout the 32 provinces to determine validity and reliability, which was demonstrated by Cronbach's α of at least 0.7 for each of the sections of thequestionnaire. 19 The final 51-item questionnaire included four sections:

Section 1: Demographic characteristics of the respondent (11 items). Section 2: Knowledge regarding symptoms of dengue and prevention methods (19 items; α = 0.7).
Section 3: Attitudes toward DF (13 items; α = 0.8).
Section 4: Practices in dengue prevention (8 items;α = 0.7).

Study Subjects: The target population of this study was all adults living in southern Vietnam. Participants were recruited if they met the following inclusion criteria: i) age at least 18years ii) Vietnamese nationality, iii) able to communicatefluently in Vietnamese, and iv) self-reporting no symptoms or diagnosis of dengue at the time of enrollment. Volunteer participants were recruited through convenience sampling. Face-to-face interviews wereconducted by ten undergraduate pharmacy students, whowere trained for a week to manage the interviews confidently. To minimize collection-related bias, no overt cues or signs regarding correct answers were given to the respondents during the interview. Incomplete questionnaires were considered as missing values and excluded from data analysis.
Statistical Analysis: Answers from the questionnaires were tabulated using Microsoft Excel 2016 for Windows® to double-check input progress, then analyzed usingStatistical Package for the Social Sciences (SPSS® 20.0). In Section 2 (knowledge), correct answers were marked as one point and incorrect or unknown answers were marked as zero, resulting in a "K-score" range from 0 to 19. In Section 3 (attitudes), a five-point Likert scale was used, ranging from 1 (strongly disagree) to 5 (strongly agree), with the mid-point being "not sure". Responses of 4 or 5were marked as one point and the remainder marked as zero (''not sure'' was marked as zero because this was most commonly the response of participants who had the least knowledge or understanding of the statements20), resulting in an "A-score" range from 0 to 13. In Section 4 (practice), dichotomous choice (Yes/No) questions wereasked; "Yes" responses were marked as one point and "No" responses were marked as zero, resulting in a "Pscore"range from 0 to 8. The mean scores from each section-K, A, and P-were compared between demographic subgroups using Chisquare tests and Fisher exact tests. A binary logistic regression analysis was also performed to calculatecrude odds ratios and 95% confidence intervals. The aim of the regression analysis was to identify predictors of the KAP level (good or poor). The good level was assigned if the total score of the section was at least 80% of the maximum score, i.e., K-score of 16-19 points, A-score of 11-13 points, and P-score of 7-8 points. Statistical significance was considered to be a p-value less than 0.05.
Ethical Considerations: This study received approval from the Science Research Committee of the Faculty of Pharmacy at the University of Medicine and Pharmacy in Ho Chi Minh City. Participants were informed of the purpose and related methodology and were asked to sign an informed consent form prior to enrollment, to ensure voluntariness and anonymity. Participants were free to refuse to answer any question and to quit at any timed uring the interview.


Table-1 shows the characteristics of participants; from the total of 2,399 participants, 493 rural participants and 493 urban participants were needed. Most study participants were younger than 30 years age(69.3%) and unmarried (71.4%). The majority (71.8%) of participants had nopersonal experience of DF (71.8%) (Table-1, Figure-1).

Figure-1 summarizes the participants' resources for information on DF, with the two most common sources being television (85.4%) and the internet (69.5%). The proportion of internet-based information was statistically different between rural and urban areas (p<0.05) (Table- 2).

Table-2 presents scores for knowledge of symptoms and preventions for DF, analyzed using binary logistic regression to identify factors that affect knowledge. Thestudy found that 37.3% of participants had good knowledge levels, with occupation, education, personal experience of DF, and knowing people who have had DF being significantly associated with knowledge (Table-3).

Table-3 shows average scores for attitudes toward DF in urban areas, rural areas, and overall, and factors that affected those scores. Of the 2,399 participants, more than half had good attitude levels, which was more than those with good knowledge levels (Table-4).

Table-4 shows scores and logistic regression analysis of good practice levels. Participants who were married or had children were 1.5 to 2.0 times more likely to have good practice levels than unmarried people without children (Table-4).Spearman correlations showed a positive relationship between good knowledge and good practices in both rural (rs=.484, p<.001) and urban areas (rs=.507, p<.001) (Table-5), while the correlation with good attitudes was much weaker.


In general, southern Vietnamese residents appeared to lack knowledge of DF symptoms, especially joint pain and bone pain, with 71.9% and 86.1% incorrect answers, respectively, to these questions. This finding was consistent with other studies in Nepal, Jamaica, Thailand, India, and Pakistan.7,9,10,12 The gap in knowledge may be explained by three factors: the low proportion of individuals who have a history of dengue (28.2%); the similarity of DF symptoms with common causes of fever, such as influenza and typhoid, which are easily confused and so ignored;21 and the relatively little official information providedby schools (54%).The relationship between school-supplied information and good knowledge can be seen in studies in Nepal7 and Jamaica, 9 and in the current study. The higher the percentage of respondents who were informed byschools, the higher the K-score obtained. Similar results from univariate logistic regression analysis in a study inIndonesia indicated that good knowledge was associated with education level, that those who obtained a higher level of education had better knowledge of DF8 Surprisingly, there was a significant difference in mean K score between rural and urban groups (p=0.025), with people living in rural areas having better knowledge than those in urban areas, despite the opposite being the case for A-scores. In comparison with previous studies, the percentage of good A-scores in Vietnam (56.7%) was higher than in Indonesia (37%),8 but lower than in Nepal (83%). 7However, the proportion of participants who obtained good P-scores was 56.1%, higher than in Nepal, Indonesia,  Jamaica, and Thailand. 7-10 The better DF-prevention practices in Vietnam might be due to community oriented policies. 22 Though not excelling in medical treatment, the Vietnamese government has focused on improving awareness of DF prevention with the motto "An ounce of prevention is worth a pound of cure." The positive effects of training strategies toward DF attitudes and self-practice was demonstrated by the results of thelogistic regression. Individuals with good K-scores had 1.7 times higher than A-scores and 5.0 times higher than Pscores. The comparable figures from Indonesia were 2.7 times for A-scores and 2.2 times for P-scores. The growth of education and training and the dissemination of DF information appears to have led to better attitudes and practices. Television, as expected, was the most common source of DF information, which is consistent with studies from Jamaica, 9 Laos, 23 Philippines, 24 Indonesia, 8 and Nepal.7,25 Encouragingly, the internet was the second most common information source. The provision of information by healthcare professionals was higher than in Nepal (half vs. a third), 7 but needs to improve in the future. The explosion of multimedia and digital materials in Vietnam in the last few years has created more avenues for disseminating information. Governments should consider television channels and web pages as essential means of education for raising public awareness about DF, while also increasing connections between patients and healthcare professionals. This study has some limitations. Firstly, the study sample was slightly skewed toward younger participants, who have more opportunities to access information than older people, leading to better knowledge and practice, but lower A-scores due to lack of experience of dengue. Secondly, desirability bias might be a factor in attitude responses, which was identified as an issue in studies in Indonesia and Nepal.7,8 This bias exists when participants give socially preferred answers to questions that do not reflect their real-world behaviors. To minimize this bias, the 5-point Likert scale was used instead of dichotomous choice questions. Thirdly, socioeconomic status was not assessed in this study due to time constraints, although it was found in the study in Indonesia that this factor had a strong association with knowledge, attitudes, and practices. 8


The lack of knowledge regarding dengue indicates a target for future strategies. Education programmes should be designed to improve knowledge, attitudes, and preventive behaviours for DF in the community, prioritizing people's knowledge and coordinating community prevention activities. Such programmes will be important for gaining community support for the application of effective measures to prevent dengue virus infection, improving monitoring and healthcare-seeking behaviours, and better controlling outbreaks. At the same time, the link between individuals and health professionals is essential in national dengue prevention programmes.

Acknowledgment: We are indebted to staffs of Faculty of Pharmacy, Buon Ma Thuot University, and Lac Hong University for their support and co-operation during data collection.
Disclaimer: None to declare.
Conflict of Interest: None to declare.
Funding Disclosure: None to declare.


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