PT  - JOURNAL ARTICLE
AU  - Hsiang-Yu Yuan
AU  - Jingbo Liang
AU  - Pei-Sheng Lin
AU  - Kathleen Sucipto
AU  - Mesfin Mengesha Tsegaye
AU  - Tzai-Hung Wen
AU  - Susanne Pfeiffer
AU  - Dirk Pfeiffer
TI  - The effects of seasonal climate variability on dengue annual incidence in Hong Kong: A modelling study
AID  - 10.1101/2020.01.20.912097
DP  - 2020 Jan 01
TA  - bioRxiv
PG  - 2020.01.20.912097
4099  - http://biorxiv.org/content/early/2020/01/21/2020.01.20.912097.short
4100  - http://biorxiv.org/content/early/2020/01/21/2020.01.20.912097.full
AB  - In recent years, dengue has been rapidly spreading and growing in the tropics and subtropics. Located in southern China, Hong Kong’s subtropical monsoon climate may favour dengue vector populations and increase the chance of disease transmissions during the rainy summer season. An increase in local dengue incidence has been observed in Hong Kong ever since the first case in 2002, with an outbreak reaching historically high case numbers in 2018. However, the effects of seasonal climate variability on recent outbreaks are unknown. As the local cases were found to be spatially clustered, we developed a Poisson generalized linear mixed model using pre-summer monthly total rainfall and mean temperature to predict annual dengue incidence (the majority of local cases occur during or after the summer months), over the period 2002-2018 in three pre-defined areas of Hong Kong. Using leave-one-out cross-validation, 5 out of 6 observations of area-specific outbreaks during the major outbreak years 2002 and 2018 were able to be predicted. 42 out of a total of 51 observations (82.4%) were within the 95% confidence interval of the annual incidence predicted by our model. Our study found that the rainfall before and during the East Asian monsoon (pre-summer) rainy season is negatively correlated with the annual incidence in Hong Kong while the temperature is positively correlated. Hence, as mosquito control measures in Hong Kong are intensified mainly when heavy rainfalls occur during or close to summer, our study suggests that a lower-than-average intensity of pre-summer rainfall should also be taken into account as an indicator of increased dengue risk.