Low level of dengue infection and transmission risk in Hong Kong: an integrated analysis of temporal seroprevalence results and corresponding meteorological data

ABSTRACT

Hong Kong is an Asia-Pacific City with low incidence but periodic local outbreaks of dengue. A mixed-method assessment of the risk of expansion of dengue endemicity in such setting was conducted. Archived blood samples of healthy adult blood donors were tested for anti-dengue virus IgG at 2 time-points of 2014 and 2018/2019. Data on the monthly notified dengue cases, meteorological and vector (ovitrap index) variables were collected. The dengue virus (DENV) IgG seroprevalence of healthy adults in 2014 was 2.2% (95%C.I. = 1.8–2.8%, n = 3827) whereas that in 2018/2019 was 1.7% (95%C.I. = 1.2–2.3%, n = 2320). Serotyping on 42 sera in 2018/2019 showed that 22 (52.4%) were DENV-2. In 2002–2019, importation accounted for 95.3% of all reported cases. By wavelet analysis, local cases were in weak or no association with meteorological and vector variables. Without strong association between local cases and meteorological/vector variables, there was no evidence of increasing level of dengue infection in Hong Kong.

KEYWORDS:

• Dengue
• Meteorological factors
• Time series

Acknowledgements

The authors wish to thank staff of Hong Kong Red Cross Blood Transfusion Service for supporting the conduct of the study. We would like to acknowledge the work of Poon CY and So KY for their contribution of collecting archived blood samples for DENV serological test, and Li Ka Shing Institute of Health Sciences of The Chinese University of Hong Kong provided technical support in conducting the research.

Disclosure statement

No potential conflict of interest was reported by the author(s).

Data availability statement

The sharing of data used in this study has been restricted by the Joint Chinese University of Hong Kong – New Territories East Cluster Clinical Research Ethics Committee due to confidentiality concerns.

Geolocation information

Hong Kong (22.3786502,114.202828)

Informed consent statement

Informed consent was waived as the samples were collected retrospectively and anonymously.

Additional information

Funding

This study was supported by the Health and Medical Research Fund (Project Reference: CU-18-C22) of the Health Bureau, Hong Kong Special Administrative Region Government.