Periodic synchronisation of dengue epidemics in Thailand over the last 5 decades driven by temperature and immunity.


Type
Article
Change log
Authors
García-Carreras, Bernardo  ORCID logo  https://orcid.org/0000-0002-0714-300X
Grabowski, Mary K 
Sheppard, Lawrence W 
Abstract

The spatial distribution of dengue and its vectors (spp. Aedes) may be the widest it has ever been, and projections suggest that climate change may allow the expansion to continue. However, less work has been done to understand how climate variability and change affects dengue in regions where the pathogen is already endemic. In these areas, the waxing and waning of immunity has a large impact on temporal dynamics of cases of dengue haemorrhagic fever. Here, we use 51 years of data across 72 provinces and characterise spatiotemporal patterns of dengue in Thailand, where dengue has caused almost 1.5 million cases over the last 30 years, and examine the roles played by temperature and dynamics of immunity in giving rise to those patterns. We find that timescales of multiannual oscillations in dengue vary in space and time and uncover an interesting spatial phenomenon: Thailand has experienced multiple, periodic synchronisation events. We show that although patterns in synchrony of dengue are similar to those observed in temperature, the relationship between the two is most consistent during synchronous periods, while during asynchronous periods, temperature plays a less prominent role. With simulations from temperature-driven models, we explore how dynamics of immunity interact with temperature to produce the observed patterns in synchrony. The simulations produced patterns in synchrony that were similar to observations, supporting an important role of immunity. We demonstrate that multiannual oscillations produced by immunity can lead to asynchronous dynamics and that synchrony in temperature can then synchronise these dengue dynamics. At higher mean temperatures, immune dynamics can be more predominant, and dengue dynamics more insensitive to multiannual fluctuations in temperature, suggesting that with rising mean temperatures, dengue dynamics may become increasingly asynchronous. These findings can help underpin predictions of disease patterns as global temperatures rise.

Description
Keywords
Dengue, Epidemics, Humans, Incidence, Mosquito Vectors, Temperature, Thailand
Journal Title
PLoS Biol
Conference Name
Journal ISSN
1544-9173
1545-7885
Volume Title
20
Publisher
Public Library of Science (PLoS)
Sponsorship
European Commission Horizon 2020 (H2020) ERC (804744)