Sociodemographic predictors of knowledge, mosquito bite patterns and protective behaviors concerning vector borne disease: The case of dengue fever in Chinese subtropical city, Hong Kong

Geographic pattern of dengue fever is changing due to the global environmental and climate changes in the 21st century. Evidence of community’s knowledge, mosquito bite patterns and protective behavior practices in non-endemic regions is limited. This study examined the knowledge of dengue, mosquito bite patterns, protective behavior practices and their associated factors in Hong Kong, a non-endemic subtropical city. A population-based random telephone survey (n = 590) was conducted three weeks after the government announcement of a local dengue outbreak in August 2018. Sociodemographic status, awareness, knowledge, protective measures, bite patterns of mosquito were collected. Results indicated high level of community awareness of the local outbreak (95.2%), symptom identification (84.0%) and adoption of at least one mosquito protective measures (nearly 80%). About 40% of respondents reported that they were bitten by mosquitoes during the study period, a high mosquito season in Hong Kong. Mosquito bites were prevalent near grassy area (63.4%), at home (42.6%) and at public transportation waiting spots (39.6%). Younger people (< 25 years old), female, those who lived on lower floors (≤the 6th) and near grassy area were at higher risk of mosquito bites at home. Respondents perceived higher threat of dengue to society were more likely to practice mosquito prevention. While residential factors affected their indoor prevention, other socio-demographic factors affected the outdoor prevention. Practicing prevention behaviors were associated with self-reported mosquito bite at home. Furthermore, the general prevention uptake rate unchanged after the announcement of local dengue outbreak. Although the uptake rate of protective measures during August was high, 40% participants reported they were bitten. Also public locations are more common area for bites, which suggested stronger mosquito prevention and control on public environments and more personal protective behaviors should be advocated.
Author summary Dengue is a mosquito-borne viral disease that has rapidly spread globally in recent years. It is transmitted by female mosquitoes by Aedes aegypti and Aedes albopictus. The best prevention method is to control mosquito population and avoid being bitten. This study is a telephone survey which examined the knowledge level towards dengue, patterns of mosquito bite and protective behavior among Hong Kong population, and is the first study examining subtropical urban knowledge, mosquito bite patterns and protective measures adoptions against mosquito. In August 2018, 590 Hong Kong residents were interviewed. Results indicated that about 4 out of 5 respondents could identify 1 symptom of dengue and adopt at least 1 mosquito prevention behavior. About 40% respondents claimed they were bitten by mosquitoes in August. The most prevalent places were near grassy area (63.4%), home (42.6%) and transportation waiting spots (39.6%). Younger age, female, living on lower level (6th floor or lower), and near grassy area were associated with self-reported mosquito bite at home. Respondents believing that dengue has a large impact to the society were more likely to adopt protective measures. While responders’ residential factors affected their adoption of indoor protective measures, other socio-demographic factors affected their outdoor adoption of protection.