The Effects of Weather and Climate Change on Dengue

Abstract

BackgroundThere is much uncertainty about the future impact of climate change on vector-borne diseases. Such uncertainty reflects the difficulties in modelling the complex interactions between disease, climatic and socioeconomic determinants. We used a comprehensive panel dataset from Mexico covering 23 years of province-specific dengue reports across nine climatic regions to estimate the impact of weather on dengue, accounting for the effects of non-climatic factors.Methods and FindingsUsing a Generalized Additive Model, we estimated statistically significant effects of weather and access to piped water on dengue. The effects of weather were highly nonlinear. Minimum temperature (Tmin) had almost no effect on dengue incidence below 5°C, but Tmin values above 18°C showed a rapidly increasing effect. Maximum temperature above 20°C also showed an increasing effect on dengue incidence with a peak around 32°C, after which the effect declined. There is also an increasing effect of precipitation as it rose to about 550 mm, beyond which such effect declines. Rising access to piped water was related to increasing dengue incidence. We used our model estimations to project the potential impact of climate change on dengue incidence under three emission scenarios by 2030, 2050, and 2080. An increase of up to 40% in dengue incidence by 2080 was estimated under climate change while holding the other driving factors constant.ConclusionsOur results indicate that weather significantly influences dengue incidence in Mexico and that such relationships are highly nonlinear. These findings highlight the importance of using flexible model specifications when analysing weather–health interactions. Climate change may contribute to an increase in dengue incidence. Rising access to piped water may aggravate dengue incidence if it leads to increased domestic water storage. Climate change may therefore influence the success or failure of future efforts against dengue.

Social and economic impacts of climate

“…These climatic factors affect the intensity of infection in areas where malaria and dengue are already endemic (59), as well as affect where the disease may spread to (60). These dynamics make measurement of climate-disease interaction challenging: Some studies aim to recover incidence as nonlinear functions of temperature and rainfall (61,62), while others parameterize ecological models of vector transmission, using model output as indices to predict cases with data (63) or simulation (64). Anthropogenic climate change is likely to shift disease ranges and increase exposure globally, but changing temperatures, rainfall, and intervention strategies complicate projections (60,65); more research in this area is needed to link climate, ecological models, and social data.…”

Assessing the effects of air temperature and rainfall on malaria incidence: an epidemiological study across Rwanda and Uganda

“…Second, we included the logarithm of the population/month at risk as an offset to adjust the malaria data by population to estimate relations on the crude incidence rate (CIR) rather than on the total number of cases as in Colón-González et al (2013). Third, whenever significant, we incorporated a smooth interaction function between the latitude and longitude coordinates of each district's centroid to model any spatial dependence in the data (Lowe et al, 2013;Wood, 2006).…”

“…Differences in the tools, criteria, and skills for diagnosis; and errors in data management may contribute to the spatiotemporal variability observed in malaria data as well (Kyabayinze et al, 2012;Yeka et al, 2012). Climate data are readily available at spatial and temporal resolutions that allow their incorporation in statistical disease models (Bouzid et al, 2014;Colón-González et al, 2013;Garske et al, 2013;Lowe et al, 2013). Socioeconomic and behavioural data, on the other hand, are often difficult to acquire at the same spatiotemporal resolution as the epidemiological data.…”

Mosquito Economics in Laboratory: a retrospective study in a tertiary care hospital in India

“…It has become a significant health problem due to expanding geographic distribution with climate change and gradual evolution from an epidemic with long year's interval into an epidemic with seasonal trend [8,9]. Vector development and survival rates are affected by temperature, precipitation and humidity although the associations of environmental factors are not consistently described in literature [10,11].…”