Crowded Household, Subdivided Flats, and Dilapidated Housing Are Risk Factors of Bedbug (Cimex Lectularius and Cimex Hemipterus) Infestation: a Cross-sectional Study of Hong Kong Households

Abstract

Background: Bedbugs have been a neglected issue globally, disproportionately affecting low-income households. The features of many deprived housing units in Hong Kong provide suitable habitats for bedbug infestations. This study aims to identify the housing risk factors for bedbug infestations in Hong Kong.Methods: Using a cross-sectional study design, online self-reported questionnaires in Chinese were distributed between June 2019 to July 2020. Data collected were socio-demographics, crowded household condition, housing type, dilapidated housing features, and frequency of noticing bedbugs in the participant’s place of residence in the past year. The latter was transformed into a dichotomous dependent variable, “bedbug infestation”. Weighted bivariate and multivariate analysis using binary logistic regression were performed on SPSS 24.Results: The study sampled N=696 participants, 63.7% have had bedbug infestations. Bivariate analysis shows a positive correlation between the number of dilapidated housing features and bedbug infestation (OR=1.28, 95% CI 1.18-1.39, p<0.001). N=663 were included in the multivariate analysis. Those aged 45-64 (OR=2.53, 95% CI 1.30-4.91, p=0.006) and have primary education or below (OR=9.43, 95% CI 3.12-28.44, p<0.001) have significantly greater odds of bedbug infestation compared to their respective reference groups, ≥65 and tertiary education. Having monthly household income ≤HKD30,000 (OR=1.69, 95% CI 1.15-2.5, p=0.008) and living in subdivided flats (OR=16.53, 95% CI 1.01-269.72, p=0.049) and crowded household (OR=1.55, 95% CI 1.06-2.28, p=0.024) increases the odds of bedbug infestation. Dilapidated housing features that significantly increase the odds of bedbug infestation are having second-hand furniture (OR=2.97, 95% CI 1.16-7.58, p=0.023), housing cleanliness issues (OR=2.66, 95% CI 1.13-6.25, p=0.024), presence of bedbugs in neighbouring residential units (OR=3.32, 95% CI 1.57-7.04, p=0.002), and presence of bedbugs on the streets (OR=1.9, 95% CI 1.12-3.23, p=0.018).Conclusions: Crowded household, subdivided flats, and dilapidated housing are risk factors for bedbug infestations. To better control bedbug infestations, there needs to be a shift from viewing infestations as a personal hygiene to a public health issue. Efforts and policies should focus on addressing the housing risk factors identified in this study and prioritise vulnerable groups such as the elderly, low education level, low-income groups, and occupants of subdivided flats.